contents 2003-3 - whitsunday discount marine boating... · contents 2003-3 columns 24 electrical...

C o n t e n t s 2003-3

C o l u m n s

24 ELECTRICALCharging To Spec: When youneed more juice to supply yourboat’s DC loads, consider installinga battery charger. Here’s how.By Kevin McGoldrick

28 POWERBOAT RIGGINGCommon Winterizing Mistakes:Winterizing a stern drive for cold-weather storage can result in costlyrepairs if the work is done too latein the season or done incorrectly.Here’s a look at what can anddoes go wrong. By Harry Swieca

46 MAINTENANCEUnderstanding Vented Loops:Knowing what a vented loop iscould save you considerableheartache and big bucks.By Susan Canfield

48 SAILBOAT RIGGING Low-Drag Props: Follow theseguidelines to inspect a folding propfor damage during the next haulout. By Harry Swieca

57 DIY PROJECTSCruise-Ready Tackle; Engine Saver;Trouble-free Head System.

64 GOOD BOATKEEPINGRestore Aged Plastic Port Frames.By David & Zora Aiken

D e p a r t m e n t s

2 CURRENTSLetters, News, Wanted

8 TALKBACK Q&A Questions from DIY Readers

10 DIY TECHNICAL HELPLINE FREE Technical Help with your subscription.See insert on page 49 or log onto DIYONLINE at www.diy-boat.com

13 Tech Tips

14 CLOSE ENCOUNTERSWhen a fiberglass boat sails into animmovable object or another boat under-way, the “glass” and anything attached toit will surrender to the impact. Read on tosee how a professional service yardrebuilt five badly damaged boats.By Nick Bailey

20 OIL TEST: TROUBLSHOOT-ING WITH OIL ANALYSISOil analysis is the most valuable tool youhave to discover problems before theyresult in major damage or failure to yourgasoline or diesel engine. Learn what oilanalysis includes, how it relates to poten-tial failure and how to properly take oilsamples. By Larry Blais

31 “HONEY I SHRUNK THECOVER”Considering the benefits and cost savings,it makes sense to master the art of shrink-wrapping. With the proper tools and fol-low these logical steps, it’s surprisingeasy.

40 BUILD A CUSTOM CANOPY A step-by-step guide to building aweather-tested cover that protects yourboat from the elements and lets you workonboard sheltered in relative comfort. By Susan Canfield

50 SOUND EFFECTSPerhaps you are considering upgradingthe factory supplied audio system on yourboat. Here’s how to design an aftermarketsystem for a small runabout, mid-sizecruiser or large yacht and install elec-tronic components, speakers and sub-woofers. By Robert Janis

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1-888-658-2628 ( w w w. d i y - b o a t . c o m ) © DIY boat owner 2003- #3 1

2 © DIY boat owner 2003- #3 ( w w w. d i y - b o a t . c o m ) 1-888-658-2628

EDITED BY JAN MUNDY

A Half Cell of Table Salt? “Corrosion Control,” written bySusan Canfield in DIY 2003-#2issue was certainly a winner as weheard from numerous readers abouta blatant and reoccurring error.

The article mentions the use of asilver/silver chloride half-cell, andthen gives the chemical symbol asNa/NaCl, which is the symbol forsodium/sodium chloride, more com-monly known as table salt, whichcertainly would yield differentresults. The chemical symbol for sil-ver/silver chloride should readAg/AgCl. Thanks for the heads-upfrom all readers who contacted us.

Styling Trends for 2004According to David McCracken,styling manager of OmnovaSolutions (web: www.omnova.com),conservative colors blended with tex-tured fabrics and graphics will ride

the wave on next year’s models. Marine color trends closely fol-

low those seen in the automotiveand home markets, which for nextyear are somewhat conservative.The traditional red, black and bluecolors return for another year withmore vibrant color limited to accentcolors of purple, teal and pastels.Classic colors remain the norm forboat interiors. An important additionis textures. Expect to see metallic,soft metal flake, diamond check pat-

terns, gator skin, geometrics, verti-cals, wovens and animal skins forthe more adventuresome.

Yes, Do Carry Expired FlaresIn DIY 2003-#2 issue there is a dis-cussion on expired flares (see “WhenSmoke Signals, Rockets and MeteorFlares Expire). I have been told thatthe Coast Guard bestows fines hav-ing outdated flares onboard, regard-less if there are the correct numberand type of in-date flares. I alwayskept the old ones to use first in anemergency but hesitate to do so now. Ion Barnes via email

Not true. The following is from theCoast Guard website (www.uscg-boating.org/safety/fed_reqs/equ_vds.htm).

“Pyrotechnic visual distress sig-nals must be Coast Guard approved,in serviceable condition, and readilyaccessible. They are marked with anexpiration date. Expired signals maybe carried as extra equipment, butcan not be counted toward meetingthe visual distress signal requirement,since they may be unreliable. Awatertight container, painted red ororange and prominently markedDistress Signals or Flares, is recom-mended.” To eliminate any confu-sion, it’s a good idea to segregateexpired and unexpired signals inseparate, clearly labeled containers.— Sue Canfield

When is a Captain not a Captain? Anyone can be a captain of a recre-ational boat, small or large. You cancall yourself “captain” or the “skip-per” with full confidence that the termapplies whether you are rowing askiff, steering a sloop or at the helmof a powerful motorboat. You canalso be the captain of a passenger-carrying vessel and, if you are acivilian, that will earn you the title of“licensed operator.” So, what’s a“captain’s license?”

This is a label that has beeninaccurately applied to the statusheld in the United States when a civil-

ian successfully completes therequirements to earn a license tooperate passenger-carrying vessels.There are many classes of theselicenses that define the boundaries ofthe holder’s legal limits of operation,such as size of vessel, waters inwhich the holder can legally operatea passenger vessel and the numberof persons onboard that vessel. To

CURRENTS

What brand of diesel engine powersyour boat?We thought we had the bulk of the most populardiesel engine brands listed in the survey postedon DIY ONLINE. But obviously not, as more than14% selected “Other” as their brand. Completeresults in alphabetical order were: Caterpillar,3%; Cummins, 5%; Detroit Diesel, 5%; JohnDeere, 2%; Kubota, 4%; Perkins, 11%; Vetus,2%, Volvo, 19%; Westerbeke, 8%; Yanmar, 27%.In the “Other” category would be Lister, Mann,Pathfinder, Nannidiesel, Farymann and others weneglected to list.

Diesel Engine Poll Results

Ever wondered why we don’t recommend usingautomotive or house paints in lieu of marinepaints? Or why marine paints are so much moreexpensive than other coatings? We questionedthis as well and asked Interlux for clarification,receiving a response from Jim Seidel.

“Resins used for house paints are generallydarker, which can effect the final color of thepaint. Bright colors, especially whites, are neces-sary for marine paints so resins, such as Soya orsafflower, are used to help achieve brighter col-ors. Less-expensive linseed oil resins are used inhousehold products and while you can get a goodwhite, it doesn’t have the same clarity (distinctionof image) or gloss. Automotive finishes are for-mulated for application techniques generally usedin that industry for production and refinishingand have greatly different properties. In reality,marine finishes are much better than automotivefinishes. Just look at the finish of a late modelcar, even an expensive one, and you’ll notice alot of orange peel in the finish. This is built intothe paint to help disguise small defects in themetal. I doubt a boat owner would accept thesame level of peel in the finish of his or herboat.”

WHY USE MARINE PAINTS?


the surprise of most boaters and to the consternation ofmany holders of these licenses, nowhere on the certificatedoes the word “captain” appear. The license does notaward or impose a rank of any kind. You are addressedas “Captain” if you hold rank in the military, CoastGuard, fire and police departments.

In the case of the licensed operator, the use of thecommon vernacular “captain” is fine to designate who isin charge. The captain is just that, the captain of the ves-sel but he or she is not a “licensed captain.” Holding anoperator’s license does not necessary mean that one is a“captain.”

Compasses were invented 4,000 years agoand until now, no manufacturerhas been able to solve theproblem of global balancing.The earth’s magnetic fieldscause compass cards to dipwhen traveling from Northernto Southern latitudes. Manufacturersmanually balance the cards for thedifferent locales. A compass, for exam-ple, that is balanced for New York maydip by the time the boat arrives in Australia. Danforth Compass has eliminated all card balancing with the development ofthe new patent-pending GlobalBalance Card System. By decoupling the mag-net and completely surrounding the card by dampening fluid within a floatchamber, the card is free to pivot north and south with the change in the mag-netic field. Effectively, the floatation chamber makes it neutrally bouyant sothe compass card remains perfectly level anywhere in the world. An addedbenefit of the floatation system is enhanced stability, particularly with smallercompasses that tend to rotate or spin in rough seas.

GlobalBalance Card System is available in a range of sizes from the 6.6cm(2-5/8") Skipper model up to the 11.4cm (4-1/2") Constellation in all cardstyles: flat, front reading and dual reading. Danforth can retrofit other exist-ing compasses. For the Corsair and Saturn modular compasses, you can pur-chase a replacement capsule.

The practical benefit of this innovation is that Danforth no longer needs tobalance cards in-house. The net savings to consumers, besides balancing andvibration-free operation, is no price increase. As with any compass, you stillneed to boat compensate the compass to allow for onboard deviation.

COMPASS SWINGS

“I was just following the Handicapped Parking sign.”

PAT

KEAR

NS

4 DIY boat owner 2003- #3 ( w w w. d i y - b o a t . c o m ) 1-888-658-2628

This may sound a bit like hair-splitting but being accurate about thenomenclature of the entitlement ispart of the responsibility. If you areseeking expert knowledge in mattersmarine, make sure that you are notmislead by the business card thatprefixes the card owner’s name withCaptain. That doesn’t happen untilthat operator takes command of avessel. Neither does this guaranteethat they are expert in all thingsmarine. Make sure the title suits thestatus. That’s where the real profes-sionalism lives. — Pat Kearns

Moisture Barrier for Bunks

Condensation is the bane that cre-ates moldy cushions or mattresses.Our boat was no exception.Installation of a few solar vents cer-tainly helped but the problemremained. While attending a boatshow in Florida, where combatingdampness is certainly more of aproblem than in Northern States, wediscovered HyperVent.

Unquestionably, this is the mostpractical solution for the preventionof condensation forming beneathberths and seats. HyperVent consistsof a rigid, 19mm- (3/4"-) thick,coarsely spun polymer that’s heat-

fused to a breathable fabric. Sincethis wire-like mesh doesn’t compress,it creates an airspace that allowsmoisture to escape, eliminating anychance of mildew build up.

Available in 99cm (39") andlengths up to 30.4m (100'), it sellsfor US$7.25 per linear 30.4cm(foot). Panels are easily cut with scis-sors and sections are glued togetherto form the desired shape.Lightweight, it weighs just 3.6 gramsper square meter (4.3 oz per squareyard). One note of caution: cut theHyperVent at least 25cm (1") under-sized to keep the material from peek-ing out from beneath cushions. Thecoarse wire-like mesh can easilyscrape legs and hands.

For the name of your nearest dis-tributor, contact Hypervent Marine,Tel: 619/224-5626, Web:www.hyperventmarine.com. — Jan Mundy

Recall from Blue Sea Blue Sea Systems has issued a volun-tary recall of its T-1 Circuit Breaker,citing a potential safety problem.There is a possible fire risk if theoperator holds the circuit breakerhandle in the “On” position after theunit has tripped, causing the contactsto weld together.

The company says that boaterswho own any of the surface mountor panel mount versions of this prod-uct (surface mount Part No. 7120-7133; panel mount Part No. 7020-7033) can arrange for a freereplacement by visiting the Blue SeaSystems Web site,www.bluesea.com, or call the com-pany at 800/222-7617. You’ll berequired to provide the part numberand serial number.

Publisher & Editor: Jan Mundy

VP Sales & Marketing: Steve Kalman

Designer: Guy Drinkwalter

Webmaster: Jeff Kalman

Circulation: Britton Hardy

Copy Editing: Pat Kearns

Technical Editing: Recreational Marine Experts

Cover design: Guy Drinkwalter

Contributors: David & Zora Aiken, Steve Auger,Nick Bailey, Larry Blais, Susan Canfield, RobJanis, Kevin McGoldrick, John Payne, WayneRedditt, Paul & Sheryl Shard, Harry Swieca

DIY boat owner™ and The Marine MaintenanceMagazine™ are registered trademarks of JMPublishing. DIY boat owner is published quarterlyby JM Publishing. ISSN 1201-5598

While all precautions have been taken to ensureaccuracy and safety in the execution of articles,plans and illustrations in this magazine, the pub-lisher accepts no responsibility for accidents, mate-rial losses or injuries resulting from the use of infor-mation supplied in these articles, plans or illustra-tions. All rights reserved. No part of this magazinemay be reprinted or used without the express writ-ten consent of the publisher.

Moisture Bagging Add moisture from condensation,humidity and warm temperatures inan enclosed, stagnant area and youhave the perfect recipe for mildew.Mildew is disguised as a usuallyblack, sometimes white growth pro-duced on surfaces by molds. Moldsare fungi, living plants that thrive in adamp, warm environment. Like ashower room, a boat offers the idealclimate for molds to grow. Optimumtemperatures range between 20°C to30°C (77°F to 86°F), relative humid-ity from 70% to 93%. (Below 62%humidity, mold growth stops.)

On boats, mildew molds feed onfabrics, painted surfaces, window

frames, woodand other sur-faces. Asmolds growand repro-duce, theycause consid-erable dam-age.

We dis-covered

Damp Rid (www.damprid.com)Hanging Closet Freshener at a RVstore in Florida and purchased a fewfor our project boats and the base-ment at home. It’s a non-electric mois-ture absorber filled with crystals thatyou hang in lockers, vee berths,engine compartments and anywherethere’s a build up of moisture. Eachcrystal absorbs more that twice itsown weight in air moisture and inabout 8 weeks or so, you have abag full of water. It makes a greataddition to your mildew combat kit.

Measuring PPMIn your article titled, “Water, Water,Just “Pure Water,’” on page 4 in DIY2003-#2 issue, you state to “fillentire system with a chlorine solutionhaving a strength of at least 100parts per million (PPM)…,” whichequates to about one tablespoon ofbleach per gallon (3.78L) of water.But how to calculate 100 PPM?

For those who don’t what to dothe math, DIY Reader Joel Albert ofPotomac, Maryland, sent us an eas-ier formula recommended by the


The article titled, “Water-Tight Fittings,” in DIY 2003-#1 issue, stated not to mix metal and plastic fit-tings: “An example of this is coupling a bronze thru-hull with a Marelon valve.”

According to Bill Mosher of Forespar, this is not the case. Bill explains: “This is a myth thatcontinues to appear in technical articles and we get frustrated when reading this informa-tion. Many builders have used this combination successfully for years.”

Before putting ink to paper, DIY wanted to verify the correct procedures so wearranged for a demonstration with Art Bandy, Forespar’s technical guru. If youplan to connect Marelon and bronze, carefully follow the guidelines below.

Before putting any synthetic valve onto bronze, the thread match is veryimportant. Bronze easily cross-threads into plastic. Bronze marine valveshave a parallel thread (as shown in photo). Valves sold for home and com-mercial use have a tapered thread. Coupling a tapered to a parallel threaddelivers limited engagement and a weak seal. Moreover, many thru-hull-valve-hose barb installations don’t pass ABYC’s 226.8kg (500lb) load test. [For a complete description, referto “Water-Tight Fittings” in DIY 2003-#1 issue.) Art suggests that smaller diameter assemblies, 12mm(1/2") and 19mm (3/4"), don’t pass this test. Because of this, Art recommends connecting only thelarger diameter thru-hulls and valves. Use Teflon tape, polyurethane sealant or pipe dope provided it’scompatible with nylon. Read the label carefully. There are some dopes with strong acid base that willattack nylon. The best installation and one that usually passes the load test and is fully compliant withABYC and ISO consists of a flange-mounted seacock, such as the type with a triangular base, mountedto the hull with a substantial backing block. — JM

ARE MARELON AND BRONZE COMPATIBLE?


Montgomery County, Marylandhealth department to disinfect drink-ing water systems.

Use one tablespoon bleach pergallon of water to disinfect. Joel lets itstand for a day but a shorter periodmight work as well. Flush thoroughlyas describe in the article. Thereafter,add 1/2 teaspoon for every 10 gal-lons (37.8L) of water should keep thenasties away.

No Foul FactsI saw your poll on bottom paint(page 2, DIY 2003-#2 issue), whichreminded me that I’ve been meaningto write you about a paint I tried onmy aluminum Marinette last year.NoFoul ZO, by Epaint(www.epaint.net), gave fabulousresults. The company claims its prod-uct produces barnacle-killing hydro-gen peroxide. For comparison, therewere patches of Trilux under thestands that weren’t recoated. Whenthe boat was hauled, these areaswere covered with barnacles whilethe Epaint was largely (not com-pletely) free of the nasty critters. It’s

worth including this prod-uct in any comparisonsDIY might undertake.Joel Albert, Potomac, Maryland

There are many variablesthat affect the success ofany bottom paint.

Substrate preparation,paint application,ambient temperature,

sea temperature and growth all con-tribute to a paint’s success or failure.Trilux is a hard antifouling, whichmeans it doesn’t wear off but doestime expire. Life span is nominally asingle season. Also, the biocide inthis paint oxidizes in the presence ofair, so the boat must be launchedsoon after painting. As you didn’tapply a fresh coat of Trilux, it’santifouling properties most likely hadexpired. A more direct comparisonwould be to recoat the Trilux as well.However, I’m a great believer thatthe best approach with any mainte-nance product is that if it works, useit!

DIY’s Helping Hand DIY’s Technical Helpline is freefor all subscribers. If youhave a problem, we’ll do ourvery best to help. Below is asampling of comments fromsome readers.

“We really appreciate the technicalsupport line. The magazine is won-derful and this service is a fabulousplus! “ Judy Taylor, “Allegro,” Minneapolis,Minnesota

“Thank you ever so much for takingthe time and energy to respond tomy questions I had about my boat’shull repair. You have helped me somuch to finalize my approach to therepair-replacement. It has taken meweeks of research and planningbefore I started this project and yourthoughts and suggestions haveanswered whether or not I’m on theright track. Even though my Switzer

was built in 1984, I love this boatand, since I have some knowledgeof laminates, I decided to give thisrepair a shot or the boat may haveended up in the bone yard, whichwould have been a sad day.” John Renner, Toronto, Ontario

“Thank you for your help! It’s reallynice to know if I have some type ofboat maintenance question, I havesomeone to ask without feelingembarrassed or stupid about askingthe question.”Steven J. Walke, “Kitty,” Panama City, Florida

“The only “stupid” question is theone that isn’t asked and those whofail to ask are the ones who shouldbe “embarrassed.” We all get anopportunity to learn something in theQ & A dialog. “

“Thank you for your assistance withthe leaking Volvo transmission. I did,in fact, have the tranny rebuiltbecause of oil leaking. However, themechanic, who was highly recom-mended by an individual in ourboating fraternity, did a rathersloppy job and has alreadyreplaced one seal that was pinchedon the installation. It would seem intalking to people that I’m not theonly one to experience shoddyworkmanship. You have a greatmagazine and a great tech service.” Bob Milsom, Sterling, Ontario

“I wanted to let you know that afterreceiving help from the TechnicalHelpline on my 1987 Catalina 30’sdeck delamination, I followed youradvice and replaced the core. Iremoved a 2m by 45.7cm (7' by18") wide piece on the port andstarboard sides. I was pleased withthe results. Also impressed were mydock neighbors who told me I wasnuts to take on this job. Unfortun-ately, I didn’t take pictures. Thanksfor the help. I’ll be a faithful sub-scriber for as long as I’m into boat-ing.” Randy Sherwood, Charlotte, Michigan

Q: When flushing a Mercury engine, do I run theengine in neutral or in gear and for how long?

A: Your engine service manual has the flushingprocess covered very well. It calls for neutralgear with the engine run at 1,300 rpm for 10minutes. During this time you must carefullymonitor the coolant temperature gauge toensure there is no overheating. — Steve Auger

TIPSALTWATER FLUSH

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The following is a small sampling ofthe numerous questions DIY receivesfrom its Technical Helpline. If youhave a boat maintenance questionand are a subscriber to DIY boatowner magazine, the TechnicalHelpline is free. It’s our way of giv-ing something back.

Please send your questions [email protected]. We try to replywithin two business days, though itmay take longer during peak times.

A Case of Weeping Core

Q: I’m meticulous about keepingthe engine room floor (bilge) cleanand painted on my 1990 Morgan44 center cockpit sailboat but I havea stain that appears, seemingly, atrandom. The weep (limber) hole inthe forward end of the engine bedhas, in the last several months,deposited a rusty water stain on the

floor, as shown in the attached pho-tos. Typically, I’ll leave the boat onSunday evening and, when I returna week later, there’s a dry stain.This occurs only every two or threemonths. I’m not experienced inengine bed fabrication techniques;so don’t really know what’s in there.Dudley Gibbs, Julsa, Oklahoma

A: I suspect you have a case of asaturated core in the sandwich lami-nate of the engine beds (stringers).Bilge water is migrating into the lam-inate from hardware not properlysealed or the limber (weep, drain)hole itself and the core has becomewater soaked. Regardless of the

leak source, you now have water inthe core and that water can breakdown the core, separate the corefrom the fiberglass skins and/orattack hardware that penetrates thecore. At some point, that waterreaches a saturation point and runsthrough the core via the path ofleast resistance, oozing the brownfluid at the lowest point, which is, inthis case, the engine bed drain hole.The staining you see could be fromrusted bolts that are now constantlywet within the core of the laminatestructure or it could be the coreitself, weeping the stain as it breaksdown structurally and chemically.You must locate the source of theleak and seal it or water will con-tinue to break down the laminate’score and eventually affect the struc-tural integrity of the hull. In the situa-tion you describe, the engine’s nor-mal operation and the related vibra-tion dynamics are aggravating theproblem. This becomes a more seri-ous concern on balsa or foam-coredhulls. Once the source of the wateringress is isolated and eliminated,you’ll need to check the enginemounting bolts and brackets for cor-rosion damage and, at the nexthaulout, you should plan on check-ing the hull and deck hardware andrebedding as needed. Whereverhardware penetrates a hull or decklaminate, there is potential for waterintrusion and subsequent core satu-ration. We recommend that all hard-ware is rebedded at least every 10years and spot-checked on newboats. A moisture meter will help toassess the extent of the problem andits source. You might want toengage a competent marine sur-veyor to do this. — Jan Mundy

Winterizing Fuel Systems

Q: I read in a DIY back issue aboutchanges in traditional winterizationprocedures of gasoline engine fuelsystems. These changes came aboutlargely, I think, as a result of ethanol

in gas. The recommendations, as Iremember, were to run carburetedengines dry and add gas mixedwith two-stroke oil to fuel injectedengines. When I spoke with aMercruiser technical rep about stor-ing my 1988 Mercruiser 5.7L stern-drive without fuel in the carburetor,he was aghast at the practice.Could you confirm what the latestrecommendations are? David Beach, “Knot Home,” Waupoos,Ontario

A: The recommendations remainthe same as we published but notexactly as you have stated. [Ed:Step-by-step sterndrive winterizingprocedures appears in DIY 1999-#3issue or on the MRT “Engines” CD-ROM.] Treating fuel systems is atwo-step process whereby you firsttreat the fuel to protect the fuel sys-tem components. Then carburetedengines are “fogged” and EFIengines are protected with a pre-

pared “soup.” To treat the fuel,remove the boat’s fuel source and ina portable tank mix up 1-gal high-octane fuel (the highest available),fuel stabilizer and two-cycle motoroil at a ratio of 24:1 or 1qt to5gals. Run the engine at idle for fiveminutes to distribute this “soup”through the fuel system. The alcoholeventually evaporates, leaving deter-gents and additives suspended inthe oil, which are then exhausted

TALK BACK Q&AHelp line 1 -888-658-2628

upon starting the engine after lay-up. You now have twochoices: drain the fuel tank or fill it full. On carburetedengines, protecting the cylinder walls and piston ringsfrom rust is done by a technique known as fogging.Remove the flame arrestor and, with the engine idling,spray storage seal, a lubricant containing an adhesivepropellant (alcohol), which evaporates and leaves agummy residue that sticks to the cylinder walls, into thecarburetors. Continue spraying until the engine stallsdue to lack of proper fuel mixture. Never use storageseal in fuel-injected engines. Instead, disconnect theboat’s fuel supply, remove fuel-water separating filterand empty the contents. Fill the filter with a 50/50 mixof fuel stabilizer and two-cycle motor oil. Reinstall the fil-ter and then run engine until it stalls. Remove the fuel-water filter and replace with a new one. If your engineis not equipped with a canister-type fuel-water separat-ing filter, mix up a “soup” of premium fuel, two-cyclemotor oil and fuel stabilizer. The motor oil suspendsadditives in the fuel and keeps fuel injectors and the fuelpump check valve from sticking. — Steve Auger

Outrage at Pump-Out Charges

Q: After damaging (hit a rock) the bottom of mycruiser, I was told by the fiberglass repairer that the fueltank must be removed in order to do the repair. On therepair bill there was a US$382 charge to “…pump outfuel tank, estimated amount 80 gallons (67L). Note thatgas will not be replaced.” When I disputed the charge Iwas told this task was a three-man job: one man to holdthe fire extinguisher, one to pump out and one for something else which I don’t remember. When I asked whathappened to the gas, I was told it was given away andthat it would have cost me more if I called a waste man-agement service. Is this charge and fuel disposal theusual or am I being taken? Alfred Mezquida, “La Familla,” Norwalk, Connecticut

A: Gas disposal is a nightmare! There are only twoways to dispose of fuel: give it away or bring in a toxicwaste disposal company, which will charge far moreper gallon than the gas was worth new. I can’t commenton the labor charge but it may be a requirement of theshop’s insurance company or a workplace regulation insome jurisdictions to have a dedicated “fire watch” per-son when handling gasoline. Gasoline is the most fright-fully dangerous stuff and most repair shops want toavoid handling it (and so do their insurance compa-nies!). Boaters should expect to pay a premium for anygas handling. Check with your insurance company tosee if these costs, as related to the repair process, arecovered in your policy. — Nick Bailey



Troubleshooting Ignition Switch

Q: How do I test an ignitionswitch? Jose Perez, “Seawolf,” Miami, Florida

A: Most carburated outboards usethe ignition switch to control theground side of the ignition. Thismeans that if the key is in the “off”position it grounds the ignition lead.If it’s a “no spark” condition (termi-nals are marked with “M” on igni-tion switch), on smaller outboardsyou can disconnect the wiring har-ness to the key switch and use themanual coil starter. On larger out-boards, disconnect the wiring har-ness and use a remote starter switchattached to the starter solenoid. Ifthe motor starts, there is a shortwithin the key switch or wiring har-ness. Be aware that the lanyardsafety kill switch, if equipped, is alsotied into the ignition and must betemporarily disconnected beforetroubleshooting. If it’s an EFI orOptimax (direct fuel injection)engine, have it serviced by a dealer

so you don’t fry the $2,000 enginecontrol unit (ECU). If it’s a “nocrank” condition, the key switchtakes battery voltage and sends it tothe starter solenoid. Have someonehold the key in the start position andcheck for voltage on the “S” termi-nal of the starter solenoid. If there ispower, there’s a problem with thestarter or solenoid. If there is nopower, the fault is in the key switchor wiring harness. As always, refer-ring to a service manual will preventdestroying more systems than youare attempting to fix. — Steve Auger

Polarity Indicator Mystery

Q: When I’m at anchor using thegenerator, occasionally a reversepolarity light comes on the AC con-trol panel. There are 50 amps com-ing into the boat with two separatecircuits. The light activates on onlyone circuit at a time. If I have bothswitches on “gen” only one warninglight comes on. If I turn off one cir-cuit, the light comes on for the other.Sometimes it just flickers and it does-n’t matter if there’s a load on the cir-cuit. It never happens when pluggedinto dockside power. Bob Long, “Ariel,” Port Washington, NewYork

A: There is a situation where falsereverse polarity indication is given.This applies to LED-type indicatorswith a resistor inserted in one leg ofthe LED. This may occur when volt-age drop increases causing the LEDto faintly glow. The causes are usu-ally due to wiring being under rated

for the load,either fromshore or onboard. Itmay also bean indica-tion of abad connec-tion increas-ing the volt-age drop. In

some cases, this may be either tothe ground connection or the neutralconnection. Your first task is to turneverything off and examine andtighten every connection. Thencheck that all ground points are cor-rect. Perhaps the generator safetyground wire is not properly attachedto the boat ground anymore. Basedon the information, it’s possibly gen-erator-related connections that haveto be examined. When somethingjust starts to occur, usually somethingelse is degrading. — John Payne

Fuse links

Q: I’m changing battery chargersand the install information requires abreaker and disconnect or a fusedisconnect on each positive cablegoing from the battery charger toeach battery. These are AWG 6 andI cannot find a fuse, maximum 25amp, for this wire size. Robert E. Rayburn, “Georgie Girl,” CatabwaIsland, Ohio

A: Complete instructions for select-ing the type and size of fuse or cir-cuit breaker for an electrical circuitappears in DIY 2002-#2 issue. Yourchoices are limited to the Blue Sea5006 MAXI Fuse Block, rated at 80amperes maximum and 32 volts DC,or a Blue Sea 7000-series thermalcircuit breaker that has a 3,000ampere DC interrupt rating and 30-volt DC rating. Where circuit protec-

tion installs in agasoline enginecompartment,battery orpropane locker,you require the T-1 series. Thesebreakers areavailable withampere ratingsfrom 25 to 150,a DC voltage rat-ing of 48 volts,and 5,000amperes at 24-

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volt DC interrupt rating. Check if your local chandlerywill order this part for you or log onto the Blue Sea web-site at www.bluesea.com.

How to Paint Arborite

Q: I have just purchased an Allied Princess with largevertical expanses of simulated teak arborite. I would liketo paint this white to transform the cave-like interior.How do I prepare, prime and paint this surface? Brian Bishop, Goderich, Ontario

A: While I have not painted Arborite, I have paintedFormica and the steps are essentially the same. Tobegin, clean well with soap and water using a stiffbrush or Scotch-Brite pad. Wipe with Interlux 202 or216 thinner (or similar) to remove all surface oil or waxresidue. Sand with 120-grit sandpaper. Because youare going from a dark to a light color, you’ll need toapply a primer. Use Prekote if you are using Brightsideor Toplac and Epoxy Barrier-Kote 404/414, ifInterthane Plus is the choice for the finish. Sand theprimer with 220-grit paper. Wipe down to remove thesanding residue and apply two or three coats of finish.You could use a yacht enamel but, for a lower gloss fin-ish, I would use the Toplac or the Interthane Plus with theflattening agent (4317 for Toplac, 2317 for theInterthane Plus) simply because they stay whiter longerindoors than does Brightside or other single-partpolyurethane paint. If you were using any color otherthan white, it doesn’t matter.— Jim Seidel, Interlux

Running Radar Interference

Q: Whenever I run my old Furuno radar with an openantenna and Garmin GPS, the GPS loses its signal. Theradar antenna is mounted approximately 61cm (2') for-ward of the GPS receiver on the flybridge hardtop.Raising the GPS receiver on a 61cm (2') extension did-n’t help. I see other boats with this arrangement anddon’t know why mine does not work.Daryl DeLullo, “SavannahSam,” Boca Raton, Florida

A: There are three different issues here. One is where aGPS antenna is mounted close to or within thebeamwidth or output of the radar scanner. It’s alwaysrecommended that antennas clear outside the transmis-sion beam. The second is that the rotating scanner maybe physically blocking or inferring with the visibility ofsome satellites and, to avoid obscuring, the antennamust be mounted well clear so it has a clear horizon.The third issue is that when radar is switched on theremay be induced interference from radar cables to theGPS antenna cable. This is often overlooked so youshould look carefully at the cable routings and


rearrange if close. This may actuallybe a problem given that physicalrelocation has not altered things. Inaddition, look at radar and GPSgrounds and ensure they are actu-ally connected and to the sameground point. — John Payne

In-Hull or Thru-Hull?

Q: I’ve read a lot about thru-hullversus in-hull transducers and now Iwant your opinion. I prefer in-hull forobvious reasons and hull bubblesshould not affect my trawler-type dis-placement boat. Stephen Camp, “Argo,” Greece

A: It’s technically possible to mountyour depth sounder transducerinside of uncored fiberglass hulls ina tube or chamber filled with non-toxic antifreeze (water only in south-ern climes), castor oil or even in ablob of silicone sealant. Such instal-lations will avoid the dreaded holecutting and reduce drag, especially

on high-speed powerboats,but don’t expect

top perfor-mance fromyoursounder,especiallyin deep

water.Inside trans-ducerswon’t work

with coredhulls or evensolid fiber-

glass ones ifair bubbles or

voids are present in the lay up.You’ll have to locally cut away thecore and inner laminate. This maycompromise the structural integrity ofthe hull, so don’t do this without con-

sulting a surveyor or boatyard.Antifouling on the outside of the hullmay also negatively affect the instru-ment’s accuracy. On the plus side, atransducer mounted in the bilge iseasily accessible for repair orreplacement. Having said this,Airmar (www.airmar.com) offers a“smart” in-hull transducer, the P79,designed specifically for fiberglasshulls. It apparently overcomes theproblems of signal loss caused bytrapped air bubbles and beambending to compensate for dead-rise. — Jan Mundy

Some Slick Coating

Q: I have what I thought was peel-ing Vertglas on my hull. After scrub-bing with the recommended removerand then floor stripper followed byMEK and getting nowhere, I havedetermined that it must be a differentcoating. Someone told me about aTeflon coating that was sprayed onto make a hull look new. Is it possi-ble to remove this? Am I stuck with apeeling coating for the next severalyears? William Hundley, “Reel Love,” Baltimore,Maryland

A: It’s highly unlikely that the coat-ing is Teflon, more likely a clear-sprayed finish. It appears you havetwo options: paint stripper or sand-ing. The concern, of course, is tominimize gelcoat damage. It wassuggested that you first try puremethylene chloride but this is nastystuff, as is the MEK, which I’m sureyou’ve already discovered, so Idon’t recommend it. Instead, applyInterlux Interstrip (which doesn’t con-tain this solvent). It is apparentlysafe for use on fiberglass, neverthe-less, I would first do a spot test in aninconspicuous area. Follow theapplication instructions carefully toavoid gelcoat damage. If this does-n’t work and I suspect it will, you’ll

have to go the mechanical route.Begin sanding with 220-grit paperand go coarser only if it’s notremoved. Use sandpaper for metalabrasives to reduce plugging of thepaper. One way to test for Teflon?It’s difficult to sand and very, veryslick. If it’s Teflon, you’ll need bun-dles of sandpaper. — Jan Mundy

Mating Jabsco with Raritan

A: I own a 2000 Harbormaster 52Widebody that has Jabsco designerseries toilets, models DS14 370752.I want to hook a Raritan Purasanwaste treatment system to theseMSDs. Do you have any suggestionson how to do this?George Hillebrand, “Get Over It,”Edwardsville, Illinois

Q: According to a senior technicaladvisor at Raritan Engineering, thePurasan is only configured and U.S.Coast Guard certified for use in con-junction with a Raritan toilet. Threemodels are acceptable for its use:the Atlantes, Crown Head andCrown Head II. However, Raritanmanufactures another certified Type IMSD, the Lectra/San MC, whichrequires the addition of salt to theflush water. The saltwater is con-verted electrochemically into a bac-tericide that reverts back to saltwater once the process has beencompleted. The Lectra/San MC willwork with your DS14 series Jabscotoilet. A step-by-step install of theLectra/San appears in DIY 2002-#1issue. Also, log onto Raritan’s web-site at www.raritaneng.com for moredetails and information regardingthe Lectra/San and its process. Boththe Lectra/San and Purasan systemsare Type I MSDs, which are onlylegal for use in areas of water notdeclared Federal no dischargezones and only on boats up to 20m(65').

Talk back Q&A

A HELPING HAND: Wheninstalling deck hardware over theforedeck or aftcabin, use extra longbolts that pass through the deck, abacking plate and add a customwooden handhold and secure withcap (a.k.a. acorn) nuts. Use this new

handhold onthe undersideof the deck topull yourselfthrough, inthis case, thevee berth.

Sandy Turney, “Sandy’s Beach,” currently inBrunswick, Georgia.

HEAT ‘N PEEL: To remove oldfaded vinyl boat names or boat reg-istrations (not painted) use a heatgun or hair dryer. Apply just a littleheat while hand peeling off thegraphic. Remove any residual gluewith 3M General Purpose AdhesiveRemover, then apply rubbing com-pound and Finesse-it to restore thegelcoat finish. [Ed: having tried theheat-and-peel technique, I still preferusing a Ferro Stripe Eliminator forthis job.]Craig Smith, “Norumbega,” Kittery Point,Maine

LAVENDER FRESH: To preventcondensation and mildew whenyou’re away from your boat, fillsmall plastic containers (e.g. yogurtor cream cheese size) about half fullof silica sand available at most craftor hobby stores (US$9 for 450gram/1 lb bag). You’ll need abouteight containers for a 9.7m (32')boat, placed in the vee birth, head,bilge, galley, engine compartment,under sinks and anywhere that mois-ture might be a problem. Purchase amedium size bag of pot pourri, andplace that around the boat in fourpie tins. The silica draws moistureout of the air while the Pot Pourrileaves a pleasant fragrance in the

boat. You can reuse the silica everyyear; just buy fresh pot pourri.Paul Murphy, “Taboma Too,” Severn BoatHaven, Ontario

NAILED AWLGRIP: Sometimes thechemical method of undoing asmall, accidental spill is not a bestchoice. I dripped a dime-size spot ofwhite Easypoxy on a recentlyAwlgrip painted hull and was ableto remove it by lightly scraping it offwith my fingernail and wet sandingwith 400-grit paper. Steve Walke, Mary Esther, Florida

CRUISERS’ EYEBROWS: If waterdrips down from the cockpit or fly-bridge and stains the cabin win-dows, install stick-on “eyebrows”available at www.marinegutters.com.Made of plastic and fitted with 3Mweather-resistant adhesive bondingtape, these gutters are easily cut tosize, bend around corners effort-lessly and attach without screws.

BELT TUNE-UP: V-belts, especiallythose driving high-output alternators,are often overworked. A slightamount of slippage can glaze beltsides resulting in low output. Besidesthe visual evidence of the black dustresidue that indicates belt wear, youcan also check for wear by grippingthe alternator pulley with both handsand trying to turn it. If the pulleyturns, adjust or replace the belt.Make sure the engine ignition is offbefore doing this test. George van Nostrand, “Dream Catcher,”Keswick, Ontario

IF THE SHEET FITS: To tell if yourjib sheets are too small, tie a figureeight knot in the end of the line andif it pulls through the sheet block, it’stoo small. Rob MacLeod, author of “From Landfalls toLegacies”

SAIL CLEANER: To remove rust,mold or blood from nylon or Dacronsails, apply a very mild oxalic acidsolution, let it sit for about 30 min-utes, then rinse off. Do a compatibil-ity check in an inconspicuous areafirst.

HEAT TO FIT: When you need toremove a plastic hose that refuses toseparate from ahose barb or installa new one thatappears too small tofit the hose end, usea hair dryer to applyenough heat tosoften the hose end.

TELLTALE SMEAR: When cleaningwindows, clean the inside by mov-ing the rag in a back and forthdirection. Clean the outside in anup/down motion. If you have smear,you be able to tell which side of thepane it’s on by the direction of thesmear. Jim Adams, Orillia, Ontario

REMEMBER THE THRU-HULLS:Next time you haul out for bottompainting, use a small paint brush andpaint as far as the paintbrush willreach inside thru-hulls to prevent sealife from growing inside the fitting.

1-888-658-2628 ( w w w. d i y - b o a t . c o m ) DIY boat owner 2003- #3 13

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TECH TIPS WANTEDDo you have a boat-tested tip or technique?Send us a photo (if available) and a description,your name, boat name and homeport and mailto: DIY TECH TIPS P.O. Box 22473 Alexandria, VA 22304

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Bristol Marine Gallery of CollisionRepairs (clockwise top left) Viking 34 withcrunched hull, deck and toerail, bent bowrail and compression fracturing of deck;C&C 25 with hull, deck and toerailcrunched; Dufour 38 has punctured hullamidships starboard side, damaged toerailand cracked deck; C&C 35’s hull torn openamidships starboard side, interior derangedand broken bow casting from a rampagingBeneteau still embedded in the hull; C&C27 received a punctured port bow, benttoerail, fractured deck and damaged inte-rior.

CLOSEENCOUNTERS The physics are inevitable.When a fiberglass boat sailsinto an immovable object oranother boat underway, the“glass” and anything attached toit will surrender to the impact.Read on to see how a profes-sional service yard rebuilt fivebadly damaged boats.

Story by Nick Bailey.Photos courtesy of Bristol Marine.

Collision repair is a staple of anymarine service yard in an area witha large sailboat population.Sailboats collide with other sailboatsbut the speed at impact is relativelylow and damage is usually limitedto property. Powerboat collisions,because of the relatively highspeeds at impact can elevate theconsequences to create work for sal-vage companies, lawyers and, tragi-cally, sometimes the coroner, ratherthan the repair yard.

Repair and replacement oftoerails, as discussed in DIY 2003-#2, is often just the beginning.Punctured topsides, cracked decks,

crushed hull-to-deck joints andderanged interiors are not uncom-mon. Deck hardware damageranges from broken lifelines to com-plete dismasting.

Phase 1 DamageAssessment andEst imat ingInsurance companies claim depart-ments have specific procedures thatapply to handling a claim for dam-age cost reimbursement so makesure you know your rights andresponsibilities under your insurancepolicy contract. The company will,very likely, assign a marine surveyorto assess the damage and to betheir “eyes” in the process. In amajor collision not all damage isimmediately obvious so some prelim-inary work may have to ensue todetermine the full extent of the dam-

age prior to finalizing the estimate.The first priority and responsibilityyou have, as the insured, is to makesure the boat is protected from fur-ther damage. That may mean theboat needs to be hauled out of thewater and put under cover. Obviousdamage is relatively easy to definebut interior removals may berequired to gain access to obscureddamage and to make sure the dam-age is fully assessed. There may beother destructive work needed toensure that all damage that may bebeyond the obvious point of impactis identified.

Finding Hidden DamageStress cracks in gelcoat are a bug-bear in collision repairs. Whenfresh, they are often nearly invisibleand result from glass laminatesbeing flexed but not obviously dam-aged in a collision. Some “blunttrauma” collisions (such as whentwo boats bump together heavilywhile traveling side by side) mayshow little obvious impact damagebut a year later the resulting stresscracks have picked up enough dirtto become plainly visible over alarge area. A hole at the hull-deckjoint, resulting from a 90°, “T-bone,”

Dufour 38: Core exposed at hull puncturecreates danger of water entry into core.

P R O S E R I E S

type collision may appear to havebeen successfully repaired but nextseason multiple stress cracks appearthrough antifouling paint and wellbelow an/or surrounding the pointof impact. Painted boats are a par-ticular problem for it can takemonths for cracks to work their waythrough the paint. In such cases, theinsurance company will be asked toreopen the file and repair the hid-den damage. It’s far better to deter-mine the extent of the damage priorto any repair effort.

Deck hardware and rigging isanother area where damage can besubtle. Lifelines are very strong andtransfer a lot of load to the bow andstern rails in a collision. If the life-lines and stanchions have beenwiped out it’s common for the bowand stern rails to be distorted.Anytime standing rigging is dam-aged, the mast should be unsteppedfor careful inspection. The mast stepand related support structures shouldalso be checked for damage fromcompression and stress loads trans-mitted by the mast.

Bulkheads do shift, secondarybond tabbing can delaminate andinterior modules can undergo subtlerelocations. Complaints such as“The head door is jammed shut” or“I can’t get the lid off the icebox”give clues. All these things requirevery careful examination. A pro willlook below and adjacent to theimpact for hints of stress cracks thatshow only under specific lightingconditions. Seams and joints in theinterior get checked for signs ofmovement. Tabbing at bulkheads,stringers and liners are checked for

delamination. It also helps to pro-vide the repair shop with a completedamage list. The shop (and the sur-veyor) may have no idea that theeight-track stereo, the late ‘70s VHF,vintage Loran and Atomic 4 allstopped working because of the col-lision shock!

Phase 2 PrepOnce a repair is authorized all ofthe damage assessment describedabove usually proceeds at the sametime as the boat is prepped forrepair. If the work requires signifi-cant glass repairs, it’s important toremove or relocated cushions andall personal gear in dust proof bagsor other dust barriers that can betaped in place in the cabin. Next,any damaged hardware such astoerails, stanchions, jib tracks, pul-pits, etc., are removed for repair orreplacement. If the hull (or deck) hasbeen holed, it’s best to do the glassrepair from both the outside andinside.

Sometimes the bow of the collid-ing vessel penetrates far enough todamage the interior of the “col-lidee.” This demands carefull dis-mantling and removals of interiorjoinery as required for either accessor repair. Interior work can presentdifficulties. Boat interior furnishingsare commonly prefabricated asmodules and installed beforeinstalling the deck. The builder neverplanned on their removal. Wherefasteners are not accessible, carefulcutting is required. These conun-drums require compromises thatmean extra moldings and trim to

cover necessary surgery and extralabor. If it proves completely imprac-tical to access the inside skin it’spossible to do an adequate outside-only glass repair, but this option isnot the first choice.

Phase 3 Structura lRepair sOnce full access to the glass dam-age has been gained glass repairsbegin. By now, the surveyor’s tech-nique of percussion sounding (tap-ping with a hammer and listeningfor the distinctive sounds that indi-cate changes in the laminate struc-ture) has been used to determinehow far delamination extends


left) Viking 34: Sometimes stress cracks arehard to spot. This photo represents about1.8 square meters (2 square feet) of hull,.6m (2') below the impact point. (right)Other stress cracks are easy to see but mayjust be the tip of the iceberg.

Grinding fiberglass inside requires protect-ing the interior with a dust barrier of plasticsheets.

(top left) C&C25: Impactcame close butdid not dis-lodge shelf inV-berth. (top

right) Dufour 38 was not as lucky. Notebroken mahogany inner liner and crackedglass headliner. (bottom) C&C 35 sufferedshifted shelving, bulkheads and broken inte-rior trim.

(top) Dufour 38:Where practical,damaged upperlaminate and coreis removed andinner layer pre-served as a base for rebuilding the laminate;(left) C&C 27: Deck core and upper lami-nate are cut back to sound material; deckflange is damaged beyond salvage.


beyond the obvious point of impact.Sometimes, this method of non-destructive damage detection isinadequate to the task and other,more sophisticated equipment isrequired, such as infrared imagery.This perimeter is marked with agrease pencil and an air-powereddiamond–edged cutting disc (or ajigsaw, carbide circular saw, Dremeltool) is used to cut away the dam-aged glass skin. If liners or joineryare still in place behind the dam-age, care is taken to not cut anydeeper than needed. In the case ofdamage to a cored laminate theouter skin and debonded core is cutaway and as much of the inner skinas possible is preserved as a basefor rebuilding the laminate.

The cutout removes any severelydelaminated glass; however, outsidethis perimeter, there remains aregion of stressed glass that hasbeen flexed heavily and micro-frac-tured. This is where the stress cracks,currently not detectible, willinevitably appear. This damaged,but not delaminated area can belarge if the hull is an easily flexedmolding. An angle grinder with a36-grit disc removes gelcoat fromthe area surrounding the cutout toreveal the condition of the laminate.If any whitish areas indicating frac-tures or subtle delamination are visi-ble in laminate, additional grindingis required to remove the damaged

glass. In this manner, the perimeterof gelcoat removal is extended out-wards until sound laminate isexposed. Gelcoat stripping canextend from a few centimeters(inches) to a few meters (yards)wide.

The next step involves grindingthe exposed laminate around theperimeter and feathering it to atapered bevel. This provides ascarfed bonding surface for newlaminates. The minimum scarf lengthis no less than six times the thicknessof the laminate; for example, a3.8cm (1.5") scarf for a 6mm(1/4") laminate thickness. Largerscarf ratios, 12:1 to 20:1, are pre-ferred for the best bond strength,especially if the boat is built withmodern DCPD (dicyclopentadiene)polyester resins. In practice, if theperimeter band of stripped gelcoatis quite wide, the scarf ratios of therepair end up being huge, which isa bonus. When repairing smaller

puncture holes, the old guideline ofkeeping the scarf to at least half thehole diameter applies. Whereaccess to the inside is possible, theinner surface receives a shallowbevel or is, at least, roughed up withcoarse sandpaper. Usually, only afew layers go on the inside.

Once the repair area is fullyground, it’s blasted with compressedair and wiped with acetone toremove dust and any contaminates.Masking paper (or 3M Ready Mask)is applied to protect the hull fromresin drips.

Any hole repair requires a back-ing attached to the inside of the hullto act as a plug and contact mold.Formica works well in this applica-tion. If the only access is outside,then an insertable plug is needed.This consists of a piece of cello-phane covered cardboard 1.5 timesthe hole diameter with a wirethreaded through the center as ahandle. A dry piece of fiberglassmaterial is cut the same size as thecardboard and is placed on top ofthe cardboard plug and alsothreaded through the wire. The glassis wetted out with resin, the plugbent and inserted into the hole, thenheld in place with the wire until itcures. After the plug cures, the wireis cut off or pushed through into theboat.

Now layers of mat and roving,roughly duplicating the original lami-nate stack and any replacementcore materials are sized and cut.Beginning with the smallest patchesfirst and proceeding to the largest,maintains a multiple bond linebetween the new and old layers.

Glass lay-up proceeds in theusual way with care being taken tochase out air bubbles. Any core isdealt with first and allowed to curebefore the outer lay-up begins. [Ed:see deck repairs in previous issue].It’s common practice to lay multiplelayers at once, though allowingeach layer to cure before applyingthe next achieves the best quality.

Pro Series

(top) Viking34: Grindingaway damagedglass. Noteexposed core.It better notrain. (bottom)C&C 25: Removing deck laminate — see

the dust fly!

C&C 25: After prep grinding, the repair isready for new glass lay-up. Note bevelededge, which represents a scarf ratio rangingfrom 8:1 to 12:1 for this 6mm (1/4") thickhull.

(top) C&C 25:Glass lay-up.Note the hulland deck flangeis kept separatedso the vinylrubrail can be reinserted. (bottom) Dufour38: Note new PVC core just visible throughthe new laminate. (top) C&C 27: Largeoverlap around location of original hole dic-tated by extensive stress cracking.

The last two layers are 1.5 oz mat.This prevents cutting into the rovingor other material when sanding andfairing the new patch.

Any boat constructed using vac-uum bag technology and advancedcomposites, such as epoxy resins,thin exotic laminates and thickcores, utilize the same repair meth-ods. A vacuum bag is also helpfulapplying clamping pressure to anoverhead lay-up.

Fiberglass repairs to interiorbulkhead tabbing, etc. are techni-cally straightforward. Just grind offthe delaminated tabbing and lay up

new tabbing but working in a hardto reach location makes it tricky.

Phase 4 Cosmet icsUsing a 1,500-rpm, 20cm (8")sander-polisher the glass patch isleveled for application of fairingputty. In many cases, the filler is sim-ply gelcoat thickened with colloidalsilica but below the waterline avinylester or epoxy putty is preferredfor better durability. Shops use bluedye, long boards and sandingblocks to create a smooth shape.

Each filler application uses a finer(less viscous) compound to fill finepinholes and air bubbles. The finalsanding uses 150-grit sandpaper.[Ed: detailed filling and fairing pro-cedures appears in “18 steps to aSmooth Finish,” in DIY 2003-#1issue.]


Dufour 38: Chasing bubbles out of a (rela-tively) small glass repair on a deck flange.

(top) Filling and fairing: First fill on Dufour38 ready for sanding. More fills will beneeded. (bottom) First fill on C&C 27repair.

C&C 35: Broken tabbing in a hanginglocker.

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Where theboat has a whitegelcoat finish, thefinal gelcoat top-coat can be colormatched success-fully. Gelcoat issprayed on, thenwet sanded andbuffed to a highsheen. If the boatwas once a boldgelcoat color thathas now faded,there is no hopeof an exact colormatch and therepair will beobvious. Someinsurers will takethis into considera-tion and may allowrepainting butdon’t be surprisedif you’re faced withthe limits of policyprovisions that ref-erence “better-ment.” If your insurance company allows, painting oneside of the hull usually costs 67% of the full price andmost people are pleased to pay the remaining 33% andcome away with a spectacular paint job. If the boat hasa painted finish, the repair is primed with two or threecoats of an appropriate epoxy primer, fine filled,sanded with 320-grit paper and painted with a two-partpolyurethane. This is buffed and blended to match therest of the hull. Even in this case color match issues oftenarise and it’s sometimes best to prep-sand and recoatthe entire side.[Ed: for more information on paintinghulls refer to “10 Steps to a Perfect Paint Job” in DIY2002-#2 issue.]

New “stucco” style deck anti-skid applied by roller on the C&C 25.

(top) Dufour 38: After spraying and cure,new gelcoat is dry sanded initially up to a400-grit finish with a dual-action sander.(middle) The repair is then block sanded byhand with progressively finer wet sandpaperup to an 800 or 1,000 grit finish. (bottomleft) Finally buffed to a gloss with polishingcompounds. (bottom right) 3M Marinemakes a full range of polishes for eachstage of the process.

Repairs on deck non-skid areashave their own issues with matchingan existing non-skid pattern. [Ed:deck refinishing options appears inDIY 2002-#4 issue.]

Phase 5 Hardware

Reinst a l l a t ionAlbeit the boat’s structure is nowrepaired and refinished, in manycollision repairs there may be stilllots to do. Stainless steel bow andstern rails often require straighteningor rebuilding with careful cuttingand welding of stainless tube fol-lowed by hours of polishing. Insome cases, it’s worthwhile to buy anew pulpit rather than rework anexisting one. Lifelines and stanchionsthat have been severely stressed arealways replaced.

Toerails always take a beatingand repairing them is an art untoitself. [Ed: refer to DIY 2003-#2issue for how to repair aluminumtoerails.] Vinyl rubrails have theirown family of repair materials andare amenable to filling, fairing andpainting. New sections of teakcaprail often need to be createdand scarfed into place. All of theseitems must be refastened and rebed-ded before the job is done to saynothing of launch, rerigging and

cleaning, all at professional laborrates.

When properly done the repairwork should be seamless and nearlyinvisible. Resale value should remainintact and the repair should surveywith flying colors.

About the author: Nick Bailey has spent25 years in the boat repair business andis service manager of Bristol Marine inMississauga, Ontario.


(left) A broken vinyl rubrail is rejoined andbonded together in the hull-to-deck joint onthe C&C 25. (right) Gouges in vinyl can befilled, faired and painted using special vinylrepair products. C&C 25 hull repair after priming. Ready

for final sand and polyurethane painting.

C&C 25: After painting, launch rerigging.Hull still needs a final buff to blend in theedges of the repair.

(Don’t Fear the Reaper)

What happens when the repair costs are toohigh? If you were unfortunate enough to be dis-masted or sunk in a collision or have some otherlarge-scale disaster befall your boat, it’s notuncommon, especially with an older boat, to findthat repair costs exceed the value of the boat.

When a repair quote approaches the net pay-out of the insured value, less the amount theinsurance company can recover by selling thewreck as salvage, the insurance company calls ita “constructive total loss” and writes off the boat.You receive a check for the insured value fromthe insurance company. If you are a skilled anddedicated do-it-yourselfer, you may find it worth-while to buy the boat back from the insurancecompany and do your own repair. The insurancemoney may not pay the cost of a professionalrepair but it may cover your costs and thensome. There might even be enough left to havecritical items done professionally while you lookafter the rest. In this situation, always have theboat surveyed by a marine surveyor beforeundertaking the repair and continue consultingwith the surveyor during and after completingthe repair. —NB

Opportunities in a Write Off

Damaged areas of teak caprail are replacedby new teak glued and scarfed into placeand then given the necessary multiple coatsof varnish.

(bottom) New tubing is cut and shaped forfit prior to welding. (left) Welding stainlesssteel is followed by careful polishing.

A new toerail is bent and fastened intoplace with lots of sealant.


OIL TEST:TROUBLE-SHOOTINGWITH OILANALYSIS

Oil analysis is the mostvaluable tool you have todiscover problems beforethey result in major dam-age or failure to your gaso-line or diesel engine. Learnwhat oil analysis includes,how it relates to potentialfailure and how to properlytake oil samples.

Story and Photos By Larry Blais

For many years fleet operators haveused oil analysis to discover devel-oping internal problems in enginesbefore they suffer major damage orfailure. Boat owners and even per-spective boat buyers are finding thatthey too can benefit from oil analy-sis.

A Spectrometer, such as anAtomic Absorption Spectrometer, anInductive Coupled PlasmaSpectrometer or a Direct CurrentPlasma Spectrometer are used todetect wear metal particles less thanfive microns (a micron is one mil-lionth of a meter). Aluminum,chromium, copper, iron, lead,molybdenum and tin are the primarytroubleshooting wear metals. It alsodetects silicon, sodium and zinc.(See sidebar, “Data: Wear Metals”on page 21.)

Wear often occurs when the oil

itself has deteriorated due to deple-tion of its additives or has becomecontaminated from outside sources.An instrument called a FourierTransform-Infrared Analyzer (FT-IR)focuses a beam of light through afilm of used oil and compares thelight transmitted at certain wave-lengths to those of the same oilwhen new. To receive the greatestbenefit from this test, a sample ofunused oil saved from the samebatch as was drawn from theengine is sent to the lab to be usedas a reference in the analysis. An FT-IR can detect soot, oxidation, nitra-tion and sulfonation.

The rate that soot (partiallyburned fuel) accumulates in the oilindicates the quality of combustionin the engine. A rich fuel-to-air mix-ture, low compression, low runningtemperature or fouled injector(s) willaccelerate the accumulation of sootin the oil. Excessive soot degradesand thickens the oil and will lead tobearing damage as well as acceler-ated piston, ring and liner wear.

Oxidation and nitration nor-mally increase at a steady ratethroughout the life of the oil.Excessive oxidation or nitration mayindicate that the optimum drain inter-val has been exceeded. If the oil isstill fairly new, it may indicatehigher than recommended operatingtemperatures or overheating.Oxidation and nitration of the oilincreases its viscosity and leads toplugged filters, lacquering, pistondeposits, ring sticking and bore pol-ishing.

Sulfonation relates to the oil’salkalinity reserves, measured byTotal Base Number (TBN), and theoil’s acidic property or Total AcidNumber (TAN). The TBN indicateswhether enough of these additivesremain to protect the engine fromacid formation and the TAN indi-cates the relative level of acid forma-tion. Rapid alkalinity reserve deple-tion and acid formation can resultfrom high air humidity, low running

temperature and/or high idle time.Corrosive acids formed duringengine operation can etch metalparts causing rapid wear.

The FT-IR instrument also scans

E N G I N E

Very high aluminum levels in the oil helpeddetermine how badly this engine was over-heat damaged when the raw-water pumpdrive belt broke.

High lead and tin levels in the oil showedthe extent of the damage to the main bear-ings after this engine ran low on oil whenthe hose to the oil cooler failed after chaf-ing on the oil filter bracket.

High iron, lead, tin and oxidation levelspredicted the debris damage to this mainbearing and its cause. Several camshaftlobes distempered from friction and woreflat because the oil broke down after aworn-down raw-water pump impeller camcaused the engine to run at an elevated tem-perature.

for the presence of water, glycol (antifreeze) and fuel. Ifthe possibility of any of these is indicated, a separatephysical test is performed for verification.

Water sometimes contaminates engine oil through aleaking gasket or seal. However, low running tempera-ture can allow condensation of combustion blow-bygases (mostly H2O steam that passes from the combus-tion chamber past the piston into the crankcase).Exhaust elbows that are too low to the waterline in wetexhaust systems and water lift muffler equipped systemslacking an anti-siphon vacuum break are far too often asource of water contamination.


Aluminum originates mostly from pistons; however, it also can come from theoverlay of the crankshaft and camshaft bearings. Aluminum should notexceed 15 parts per million (PPM) in most marine engines during the normallife of the oil.

Chromium wears from piston rings, and ball and roller bearings. Chromiumshould not exceed 15 PPM in most marine engines during the normal life ofthe oil.

Copper normally leaches from the oil cooler core especially during periods ofdormancy. A much more serious source of copper is the underlay of mainbearings and rod bearings. Other sources of copper are wrist pin and rockerarm bushings, turbocharger shaft bushings, and oil pump drive. Coppershould not exceed 25 PPM in most marine engines during the normal life ofthe oil.

Iron is a wear metal from cylinder liners, piston rings, oil pumps, crank-shafts, gears, camshafts and several other parts of the valve train. Ironshould not exceed 100 PPM in most marine engines during the normal lifeof the oil.

Lead comes from the overlay on main bearings, rod bearings, and camshaftbearings. Lead should not exceed 25 PPM in most marine engines during thenormal life of the oil.

Molybdenum comes from the top piston ring on some engines. Molybdenumshould not exceed trace amounts, however greases containing molybdenummay find their way into the oil.

Silicon in a special form is used as an oil additive to retard foaming of theoil. Silicon in the form of “dirt” should not exceed 15 PPM in most enginesduring the normal life of the oil.

Sodium in a special form is used as an oil additive. Sodium as a salt is foundin antifreeze and saltwater and may indicate a coolant leak or wet exhaustsystem problem.

Tin can come from the overlay on main bearings, rod bearings and camshaftbearings. Tin should not exceed 15 PPM in most marine engines during thenormal life of the oil.

Zinc is an oil additive and often exceeds 1,000 PPM in better oils.

DATA: WEAR METALS


Glycol contamination of the oilindicates an antifreeze coolant leak.Pressure testing the cooling systemmay reveal the location of the leak.

Fuel contamination of the oilindicates a fuel system problem suchas a leaking fuel injector(s) or a rup-tured diaphragm in the fuel supplypump. Fuel dilutes the oil reducingits viscosity and lubricity resulting inbearing damage and acceleratedpiston, ring and liner wear.

Sampl ing Formula To get the greatest benefit from oilanalysis there are four things youneed to do. First, provide all theinformation about the engine asrequested on the sampling label.The make and model, the hourmeter reading, hours on the oil andthe brand and weight of the oil arecritical for a complete analysis. Thedate the sample was taken is alsoimportant. The serial number helpsdetermine the vintage of the engineand identify the engine for trendingwith later sampling. Was any make-up oil added that would affect theanalysis? Was the filter and/or oilchanged at time of sampling? Don’tforget to include the boat’s identityand contact information. If the boat

has morethan one

engine, identify which engine thesample is from. Filling out the labelbefore taking the sample may helpkeep the label clean.

Take oil samples at regular inter-vals. As the number of samplingsincrease, chart the results to findtrends that would indicate trouble.

Use oil analysis to help deter-mine the most cost-effective oilchange interval for this particularengine.

Lastly, use oil analysis to dis-cover problems, then confirm thesource(s) through further testing andinspection before they result inmajor damage or failure. Exhaustsmoke, fuel consumption, loss ofpower and internal noises can helpto establish engine problems. Oilanalysis should not have to be usedas the sole indicator of trouble.

Other F luid Che cksEngine coolant analysis can be quitehelpful in discovering engine prob-lems such as a leaking oil cooler, anair leak into the coolant, defects inelectrical ground connections, spentmetal pitting protection, leakinghead gaskets and destruction ofiron, copper and aluminum compo-nents.

Marine gear fluid analysis candetect impending failure from sev-eral sources including overheat,excessive wear and water intrusion.Hydraulic fluid analysis helps dis-

cover sys-tem wearand possi-ble dam-age.Diesel fuelanalysiscan reveala microor-ganisminfestationand othercontami-nates.

Manylaborato-

ries offer all these analysis and gen-erously provide help to those need-ing these services. For dieselengines, I have found the Caterpillardealerships that operate Cat’s S-O-Sprogram to be especially helpful.

About the author: A master mechanic, mastershipwright and marine surveyor, Larry Blaishas operated boatyards for more than 30years. He teaches classes for the UnitedStates Coast Guard, Havorn Marine Surveyand Shipwright’s School, University ofWashington’s Sea Grant program and hostsworkshops in diesel care for the NorthwestSchool of Wooden Boatbuilding.

Engines

(left) Elevated iron, lead, tin and copperhelped discover the bent rod that thisengine suffered when water intrudedthrough a poorly installed exhaust systemand hydraulic-locked the piston when itwas started. (above) Note the wear patterninto the copper layer of the bearing. This isdue to the rod being bent and is calledradius ride.

Oil that tested positive for water, glycol andhigh levels of sodium revealed the perfora-tion of this cylinder wet liner from corro-sive pitting that allowed coolant to leak intothe crankcase.

The engine containing the top main bearingtested positive for water and showed ele-vated lead and tin indicating excessive bear-ing wear. If it hadn’t been caught and thesource of water repaired, this bearing wouldhave worn until it looked like the bottombearing. The engine containing the bottommain bearing was showing elevated copperafter the overlay was worn away exposingthe copper. If this problem had not beendiscovered, the prospective buyer wouldhave unknowingly purchased a vessel need-ing extensive repair.


Vacuum extraction is the recommended methodof taking an oil sample if the engine is notequipped with an oil sampling probe valve. Thisvalve allows insertion of a probe while theengine is running. The engine’s oil pump pumpsa metered amount of oil through the probe intothe sampling bottle. With vacuum extraction, alength of plastic tubing is inserted into the oilsump (usually down the dipstick pipe). The vac-uum created in the bottle by a hand-operatedvacuum pump draws oil up the tube into thesampling bottle.

Never take samples from the drain stream,the waste oil container or the used filter asdoing so usually results in an unrepresentativesample. Don’t take samples from a cold engine,as wear components tend to settle over time.Run the engine until it’s warm (usually 15 min-utes is sufficient) to assure that the oil compo-nents and any contaminants are thoroughlymixed and in suspension.

Supplies needed include a sampling kit, a vac-uum pump, a length of clean tubing, and a tub-ing cutter. The sampling kit typically includes asampling bottle, “New Oil” bottle, identificationlabel and shipping cylinder. All supplies are read-ily available from an oil analysis laboratory.

Step 1 Mark the new tubing to the length of the dip-stick. This mark is used later as a reference

TAKING AN OIL SAMPLEwhen inserting the tubing into the engine’s oil sumpthrough the dipstick pipe.

Step 2From this mark add enough tubing to reach fromthe dipstick pipe to the vacuum pump (upright) andcut with a clean tubing cutter. Cutting the tubingwith a pocketknife is not only difficult but oftenintroduces contaminates into the sample.

Step 3Insert the tubing into the head of the vacuum pumpuntil it extends about 25mm (1”) beyond the pumpbase and gently tighten the retaining nut.

Step 4Remove the lid from the clean new sampling bottle

and screw the bottle onto the pump. Protect the lidfrom contamination and minimize the length oftime that the lid is off the bottle.

Step 5Insert the tubing into the dipstick pipe to the markmade earlier. Don’t let the tubing touch the bottomof the sump where it could pick up concentratedcontaminates.

Step 6Hold the pump upright and slowly pull the handleto draw the oil. Fill the bottle to the proper mark(usually about 3/4 full).

Step 7Withdraw the tubing from the engine.

Step 8Unscrew the bottle from the pump and screw on thelid. Make sure the outside of the bottle is clean andinsert it into the mailing cylinder with the completedlabel. Most labs recommend that a sample ofunused oil saved from the same batch as wasdrawn from the engine be also sent. This is used asa reference in the analysis. The “New Oil” bottle fitsin the mailing cylinder with the drawn sample.

Step 9Remove the tubing from the pump and properlydiscard. Never reuse the tubing.

Important Note: Never use the samevacuum pump for extracting coolantsamples and oil samples. Glycolresidue can cause a “false positive”in oil samples taken later.


CHARGINGTO SPEC

When you need more juiceto supply your boat’s DCloads, consider installing abattery charger. Here’show.

By Kevin McGoldrick

It’s almost a given these days thatmost vessels will have a plethora ofelectricity hungry goodies onboardfrom an anchor windless to exten-sive cabin lighting and electronicnavigation devices. Advances ininverter design have allowed manyto enjoy the convenience of ACpower without the expense andinstallation problems of a genset.

All of these modern day won-ders have one thing in common —the need for DC power and lots ofit. Large battery banks and a meansto recharge them are required to getthe most from youronboard electrical sys-tem. Even vessels withmodest power require-ments need a safe andconvenient means torecharge batteries. Asidefrom an engine-drivenalternator, most boatowners add additionalcharging capacity in theform of an AC batterycharger to meet thisneed.

This was exactly thetask I had before me onmy own vessel, a vintage11m (36') Luhrs sedancruiser. I had determinedthat a dual battery bank

configuration would work best. Bankone is the house bank dedicated toall DC loads on the boat with theexception of starting the engines. Itconsists of two 6-volt Trojan, deepcycle, lead acid batteries wired inseries with a capacity of 400 amp-hours. Bank two is the engine-start-ing bank, con-sisting of twoGroup 27,lead-acid bat-teries and isdedicated tostarting thetwin engines.Batteryswitches allowme to crossconnect thebanks to allowthe engines tobe started withthe house bankand the start-ing bank tosupply thehouse loads. Ahigh-outputalternator on the starboard enginerecharges the house bank, while astock alternator on the port enginecharges the engine bank.

Before we begin let me provide

a word of warning. Working withAC power is dangerous, especiallyon a boat with confined workspacethat is surrounded by water. If youhave any reservation about whatyou are doing, hire a competentmarine electrician (ABYC-certified isbest). Use this article to review your

installation withyour electricianbefore work startsto be sure yourboat will stand upto a compliancesurvey when thetime comes.

Qual i fy ingFactorsA battery charger isa unique piece ofonboard electricalequipment becauseit’s connected toboth AC and DCelectrical systemsthat subject it to alaundry list of elec-trical requirements

under ABYC standards. Of majorconcern is where the unit is located.On gas-powered boats, locating acharger in an area that requiresignition protection, such as the fuel

EL E C T R I C A L

Battery charger during installation. Notethat additional AC and DC case groundingwires are not installed yet.

Typical battery charger installation as recommended by ABYC Standards A-20.

FIGURE 1

ABYC

tank or engine compartment, means that it must meet theignition-protection requirements of SAE J1171 orUL1500. On all boats, the charger must be securely fas-tened to a bulkhead or other structure and the bottom ofthe charger must be positioned at least 61cm (24") fromthe normal accumulation of bilge water to protect it fromsplashing.

The charger’s input current (AC) and output current(DC) must be protected with fuses. Another fuse isrequired at the point where the positive lead from thebattery charger connects to the DC system (refer toFigure 1). If your charger uses a three-prong AC con-nection plug, as mine did, an additional grounding wireis required from the charger case to the AC groundingpoint. Similarly, an additional grounding cable isrequired from the charger case to the boat’s commonDC ground. Finally, the most overlooked aspect of acharger installation is to appropriately size the cablefrom the battery charger to the point where it connectswith the DC system. To be conservative, I sized thesecables to keep voltage drop to less than 3% at the bat-teries. [Ed: for ABYC voltage sizing charts and to deter-mining conductor size in 24-volt and 32-volt systemsrefer to’DC Wiring Handbook” in 1998-#4 issue orMRT “DC Electrical Systems” CD-ROM. ]

Which Charger? I purchased a Newmar model PT40, 40-amp batterycharger capable of charging up to three battery banks.It’s a multi-stage or “smart” battery charger thatrecharges batteries in three stages resulting in a fastercharge and maximum battery life (Figure 3). The bulkstage applies maximum current to the batteries whenthey can best tolerate it to bring them up to about 80%of a full charge. The absorption stage then maintains thehigher charge voltage as the current gradually reducesuntil the battery plates are “saturated,” meaning theyare at approximately 100% or fully charged. Finally,the float stage takes over at a slightly lower voltage,applying only a small amount of current to the batteriesto overcome their natural discharge rate and safelymaintain them at 100% charge.

The PT40 is ignition protected and comes with inputand output fuses built into the case. This charger iscapable of charging battery banks up to 400 amp-hours


Three-phase “smart” battery chargers results in a faster charge max-imum battery life.

FIGURE 3

NEW

MAR

A custom installation of a batterycharger usually requires that youmake your own cables rather thanpurchasing pre-made cables in stan-dard lengths. Installing lugs ontothick marine cable is not difficult ifyou have the proper tools.

By Kevin McGoldrick

You’ll need the following tools andmaterials to make one cable. Pricesare approximate and in U.S. dollars.

• Cable cutter, to produce a $36smooth straight cut

• Lug crimping tool $29

• Butane torch or heat gun $22to shrink tubing to $70

• Hammer

• Sharp utility knife

• Cable

• Lugs sized for the cable and connecting stud

• Adhesive-lined, heat-shrink tubing

Determine the length of the cable by actuallyrouting it and supporting it every 45.7cm (18").Allow extra length at each connection point tocreate a drip loop so that water cannot travel thecable to the connection point. Make sure the endsof the cable are cut cleanly and evenly with thecable cutter. Remove the cable and cut approxi-

EASY-TO-MAKE BATTERY CABLES

in capacity. On my boat, it safelycharges my batteries and suppliesall DC loads at the same time. Aselector switch allows the user tocharge AGM, gel cell or lead-acidtype batteries. It’s important that thisswitch be set to the correct batterytype before charging begins.Charging AGM or gel cell batteriesas if they are lead acid could dryout their electrolyte and cause pre-mature failure or possibly cause thebatteries to meltdown.

Wiring IssuesAs this charger uses a three-prong


Position the crimp tool in the middle of thelug barrel.

Little or no wire should be visible outsidethe lug.

Example of what a good crimp looks likeafter the hammer blows. Note how thestrands of the wire and the walls of the lugappear as solid copper.

A heat gun produces the best results whenshrinking tubing. Note how the adhesive issqueezed out forming a watertight seal.

plug for connection to the boat’s ACsystem, I had to install an outlet inthe engine compartment. I was ableto daisy chain off an existing GFCIAC outlet in the cabin and installeda standard receptacle in a water-resistant Carlen outlet box (a brandname of plastic electrical boxesmade for outdoor use). By installingthe engine compartment outletdownstream of a GFCI outlet, it toois protected. With the exception ofspecialized hospital equipment, I’mnot aware of ignition protectedGFCI outlets for marine applications.Similarly on/off switches or breakers

serving the engine compartment aremore easily installed outside of theengine compartment in areas whereignition protection is not an issue.

ABYC Standards (A-20.7.3)state that the charger must remainconnected via the AC groundingwire (the green wire) during servic-ing even when the hot and neutrallegs have been disconnected. This isdone to prevent electrical shock atthe unit should AC power energizethe charger via the DC groundingwire (presuming the AC and DCgrounding systems are connected asper ABYC standards). Since this

mately 16cm (5/8") of the vinyl cover off eachend. Be careful not to nick the wire strands with theknife when removing the cover. It’s best to cut thecover around the circumference of the cable, thenmake one cut from there to the cable end. This willallow you to peel the cover off rather than attempt-ing to slide it off as is done with smaller wire. Theexposed wire should bottom out in the lug with littlebare wire visible.

Using the crimping tool select the correct size slotfor your wire and align the lug so that it crimps atits midpoint. Strike the crimping tool with a ham-mer, using multiple blows if necessary, until the toolis fully compressed. Be sure to hold the tool and lugin place so that subsequent blows strike the lug inthe same spot each time.

Next, cut a length of shrink tubing long enoughto extend from the barrel of the lug to about aninch over the vinyl cover. Be sure to purchase adhe-sive-lined shrink tubing. During shrinking the adhe-sive melts to form a strong and watertight seal.Shrink the tubing using a heat gun, butane torch orsimilar device until a bead of adhesive is formedaround the ends of the tubing. Be careful not toburn the wire cover. Use caution when using anopen flame on a boat especially in compartmentsthat may contain explosive gases. Ventilate thework area well before starting the flame andalways have a fire extinguisher at hand for instantuse. Allow the lug to cool completely before disturb-ing the wire. This gives the adhesive time to set andproduce a strong bond. Reinstall the cable andstand back and admire your work. A cable createdin this manner will likely last the life of the boat.

charger uses a typical three-pronged plug, the ground-ing wire is disconnected when I unplug the unit for ser-vicing. As a result, I had to add an additional ground-ing cable from the case of the charger to the groundingwire of the outlet, which always remains connected.

Wiring the DC side of the charger is similar to theAC side. The negative output cable connects to the DCcommon ground point; the positive output cable con-nects to the battery positive post. A DC-grounding cableconnects the charger case to common ground. The posi-tive cable from the charger to the battery is energizedvia the battery when the charger is off. Since this cableis not fuse protected at the power source (the battery inthis case), ABYC Standards (A-20.6.3) require that afuse be installed within 18cm (7”) of the battery. Shoulda short occur when the charger is off, this fuse protectsthe cable.

All cables must be sup-ported throughout their runat least every 45.7" (18").It’s good practice to createa drip loop where thecables attach to the batter-ies and charger so thatwater is less likely to travelthe cable and cause ashort.

Siz ing for Vo l t ageDropOne of the most commonmistakes is to install thewrong size cable from thebattery charger to the bat-


teries. Usually, this involves cable that is too small creat-ing a large voltage drop at the batteries but I have alsoseen massive cables installed, which is just a big wasteof money. In my installation, the charger output is 40amps and is 2.4m (8') from the batteries making a totalcable run of 4.8m (16'). Using this information andallowing for a 3% voltage drop at the batteries, thecable sizing chart calls for 6 AWG cable. [Completetables to determine wire size requirements based onvoltage drop are found in DIY 1998-#4 issue and theMRT “DC Electrical Systems” CD-ROM.]

About the author: Kevin McGoldrick is a freelance writer and amarine surveyor located in Long Island, New York. His website(www.mmsurveying.com) features information on getting the most outof your next survey.

-

+

Shore Power Inlet

Two pole breaker Engine room outletCharger three prong plug

Battery charger

Case Ground

Battery 1

AC common grounding bus

DC common grounding bus

Additional AC & DCgrounding (alwaysconnected)

Fuse

Battery 2

To vessel DC loads

AC DC

Hot

Neutral

Ground

-+

H

N

G

-

+

H

N

G

Wiring schematic shows author’s installation of 40 amp-hours charger.

GUY

DRI

NKW

ALTE

R


COMMON WINTERIZINGMISTAKES

Winterizing a stern drivefor cold-weather storagecan result in costly repairsif the work is done too latein the season or doneincorrectly. A marine sur-veyor provides a first-handlook at what can and doesgo wrong.

By Harry Swieca

Gas prices and the yearly rituals ofstoring my boat are two things I dis-like most about boating. If you arein the less fortunate group that boatwhere winter temps drop belowfreezing, the best you can do ismake the winterizing job as painlessas possible.

It’s now fall. Your boat sits “onthe hard.” You’ve been too busy towinterize the engine but plan to doit some weekend soon. All it takes isa one night of below-freezing tem-peratures and you risk freeze dam-age to your engine. As a surveyorI’m often asked to inspect engineswith freeze damage. (Many insur-ance companies don’t cover freezedamage.) Even during a mild winter,like the winter of 2002 (in Illinios), Irecorded the highest number offrozen engines on record. So what’severyone doing wrong?

Co ol ing ProblemsBeyond the nuts, bolts and comput-ers on the most sophisticated

engines, your engine relies on water(raw or fresh) to remove heat. Afreshwater or closed-cooled systemincorporates a heat exchanger(Figure 1). This has two separatechambers, one holds the internalengine anti-freeze, the other hasnumerous cooling tubes throughwhich is pumped cold freshwater.As freshwater passes through thetubes, heat is removed from theantifreeze mixture (Figure 2).Closed cooling systems are easy towinterize. Only the raw-water sideof the exchanger and the raw-waterpump are serviced. The main cool-ing chamber and engine block arenot tampered with other than tocheck the coolant concentration orreplace the coolant every few years.

Raw-water cooling is a differentmatter. This setup requires winteriz-ing of the engine and all its parts incontact with water. All are protectedin one of two ways: either by drain-ing the entire system or by pumpingantifreeze through the system. Ratherthan dwell on the aftermarket winter-izing and pumping systems avail-able, your service manual will rec-ommend the best method for you toemploy. If not, have it winterized assoon as possible by your dealer andwatch how it’s done. Pay closeattention to the products they use.

Myth about Freeze Plugs During my fledgling car mechanicdays, I was taught that all engineshad freeze plugs and when temper-atures drop the plugs pop out tokeep the block from cracking. Onlyafter becoming a marine mechanicdid I learn the truth. Freeze plugsare in fact called welch plugs. Theyare round mushroom type caps thatare pressed into the large holes onthe sides of the cylinder block andcylinder heads (Figure 3). Marineengines use brass plugs to minimizerust. What’s important is they do notpop when the engine freezes. Suchplugs just seal the holes used toremove sand from the block after

casting. They are not designed asfreeze plugs. If a plug happens topop out, it was only because it wasnot installed properly or the ownerwas just lucky.

P O W E R B O A TR i g g i n g

Typical heat exchanger located on the topof an engine usually towards the back. Capis used to fill and maintain the system.

Inner metal tubes allow water to passthrough, cooling the antifreeze. View alsoshows location of the internal sacrificialanode for corrosion protection of the sys-tem.

1

2

Because of the design of the internal cool-ing chambers, freeze damage in cylinderblocks usually shows in the same areas.

What was left of a 454 engine block after aquick cold snap. Note that both welch plugsare still in place.

3

4

When water freezes in an engine, you’ll typicallyfind cracks in the block and manifolds and always inthe same location. The block cracks just above the pet-cock or just below the cylinder head (Figure 4), themanifolds crack at the lowest point of the casting(Figure 5). Where it cracks is not important, if it’scracked, it’s trash.

Proper Dra ining Pro ceduresCarefully follow the service manual when winterizingyour engine and don’t take shortcuts. On the sides ofthe cylinder block and on each side of the exhaust mani-folds are metal or plastic petcock drains or brass pipeplugs (Figure 6).

While opening the valves does allow water frominside the engine to drain, it isn’t enough to keep it fromfreezing. The inside of the block and manifolds fill withantifreeze residue, silt, sand or mud during normal oper-ation. This sediment accumulates at the bottom of theblock or base of the manifolds. Opening the petcock isnot enough. The best way to insure complete drainageis to remove the petcock or plug completely, and probethe hole with a small screwdriver as it drains (Figure7). When a solid stream of clear water or antifreeze isvisible, allow it to drain completely. As a final step


Manifolds alsocrack in the sameareas.

Drain cocks arebrass pipe plugs,or brass or plasticinserts. All shouldbe removed, ratherthan opened.

Using a smallscrewdriver as aprobe will open ablockage of sand orsilt and allow com-plete drainage.

5

6

7


probe each hole again to make sureit has drained completely. With theblock and manifolds completelydrained, look for other low areassuch as the main circulating pumphoses (Figure 8). Oil and transmis-sion coolers should also be drained.Check the hoses or drain plugs andprobe for plugged holes (Figure 9).Remember to pull the plug on theraw-water pump or the housing willcrack. If you follow the manual, thismethod is safe and inexpensive.After the water is drained, it’s goodpractice to reconnect all hoses, butleave all plugs out and on top of theengine until spring just in case thereis an air bubble in the system thatneeds longer to drain.

Ant i fre eze Fact sUsing antifreeze to winterize andprotect your closed-cooling or raw-water engine is the safest way ifdone correctly. It not only protectsthe internal parts of the block fromfreezing, it also provides rust protec-tion. Again, follow your manualcarefully if it recommends thismethod. The most common mistakeswhen using antifreeze are listedbelow.

Never use straight (undiluted)antifreeze. It doesn’t provide betterprotection than the required 50/50ratio of water-to-antifreeze mix.Antifreeze just doesn’t work until it’smixed with water. [Ed: make sure

the antifreeze that you use is thenon-toxic plumbing type, known aspropylene glycol, that will not pol-lute the environment.]

Always drain the engine block

and manifolds prior to using yourpremixed antifreeze solution. Waterin the engine further dilutes the solu-tion and decreases protection.

Never run the engine on waterand then add antifreeze through theengine’s thermostat hose. Thechange in coolant temperaturecloses the thermostat not allowingenough of the solution to enter thecylinder block, which may still befilled with water.

Always run the engine for atleast 15-minutes to circulate theantifreeze. Take the time to checkthe protection level of the closed sys-tem coolant before winterizing(Figure 10). [Ed: always use “oper-ating” antifreeze or ethylene glycolin the heat exchanger. Bottleslabeled “contains silicates” or “low-silicate formula” are clues that theproduct is an operating antifreeze.]

Never use a high-poweredpump to force the antifreeze solutionthrough the engine. This can feedback through the exhaust systemand hydro-lock the engine causingserious damage.

Whatever way you choose towinterize your engine, either bydraining, pumping antifreezethrough the system or an aftermarkettank and gravity kit, read the instruc-tions carefully and don’t take short-cuts. Remember, don’t wait, do itnow!

About the author: Harry Swieca specializes inarticles on engine maintenance and serviceand is a frequent contributor to DIY.

Powerboat Rigging

Remove the filler cap on the heat exchangerand use an antifreeze tester to check thestrength of the coolant. Change coolant asneeded, depending on storage temperatures.

Your engine may have several engine oilcoolers and or transmission oil coolers.Disconnect and drain the hoses is the mostpositive way to be sure the unit is protected.

The main water circulation pump may haveseveral low hoses that must be removed tocompletely drain the pump.

9

Story and photos by Jan Mundy

MaterialsInstallation kitHardware kitEnd capsVents Access door (optional)Ladder 9kg (20lb) propane tank, Fire extinguisherGloves (fire-proof)2x4 studs SawStaplerWrench Tape measure

Walk about the boatyards and yousee all types of boat covers. Framesmade of 2x4s, conduit, ABS piping,often draped with cheap tarps invarious stages of decline. A scarcefew boats are fitted with custom-made covers. I’ve engineered threecovers based on yard designs forour 6.7m (22') powerboat, all withmediocre results.

Year one, I didn’t want to paythe $20 per foot (per 30.4cm)quoted to shrink-wrap the boat, so Ihung a tarp over wood supports.Year two, a rope gridwork sup-ported the boat’s trailering cover.Year three consisted of an elaborate

support structure made of ABS pip-ing that was covered with the worn,patched boat cover and numeroustarps. Three strikes equal an out. Ado-it-yourself shrink-wrapped coverappeared to be the best option and,from what I’d observed, it didn’tseem beyond my capability.

I’d heard lots of “wharf chat”about other boater’s experienceswith taking on the task but ratherthan rely on the war stories, Idecided to check it out for myself.

Paul Murray, store manager ofBoat/U.S. in Mt. Clemens,Michigan, agreed to organize ashrink-wrapping demonstration withMike Stenberg of Dr. Shrink(www.dr-shrink.com). Mike has“wrapped” hundreds of boats whileinstructing boatbuilders and duringdemonstrations at trade shows. Wemet Paul and Mike early at the storeon a calm, windless day.McMachen Marine (www.mcmachenmarine.com), a nearbyboat dealer supplied the demo boat,a 6.7 (22') Four Winns bowrider.Before we show you the steps towrapping like a pro, let’s review thecomponents of the job.

Not a l l F i lm i s EqualShrinkwrap (also referred to as“film”) is available in various widths,lengths and thickness and comes inblue, white or clear.

Blue film performs best in north-ern climates as it absorbs heat,which allows snow to slide off.White transmits natural light, anadvantage for brokerage boats orworking on the boat in warm cli-mates as it doesn’t shed snow. Theclear film is also best used in warmclimates but is the most difficult tohandle as it doesn’t show the telltaledistortion that precedes a burnthrough. Amateur “shrinkers” shouldstick with blue or white.

Shrinkwrap, like most plasticsheeting, is rated in mls. The higherthe ml, the thicker the material. A6ml or 7ml are strong enough towithstand hail, rain or snow and arerecommended for boat storage cov-ers. Thinner films, typically used byboat manufacturers when transport-ing boats, are tricky to use as theypuncture easily during the shrinkingprocess. The thickest film is 12ml, aspecialized flame-retardant materialfor commercial use.

Some films are better than oth-ers; purchase buy the best gradeyou can afford. Inexpensive filmstend to burn through easily, causingholes and requiring mending. It’sshortsighted to cheap out on theprice when the difference betweenbarely adequate and adequate qual-ity may be relatively insignificant ona 12m (40') boat. Quality films havehigh opacity (not transparent) and


REFIT

need toclip

“HONEY, I SHRUNKTHE COVER”Shrink-wrapping a boat is an enigma to some people,even to those that have previously tackled this task.Considering the benefits and cost savings, it makes senseto master the art of shrink-wrapping. With the propertools and these logical steps, it’s surprising easy.


are UV protected. Dr. Shrink films,for example, are warrantied againstUV breakdown for 12 months.

To ols for SuccessTwo tools are key to a successfulshrink-wrapped cover: a tensioningtool to tighten the perimeter bandand a propane-fired heat gun toshrink the film.

The perimeter band is a verytight piece of strapping that runs hor-izontally below the boat’s rubrail(sheer) to secure the entire cover.This band must be extremely tight soit doesn’t move up and down andchafe the hull. A heavy snow loadcan also weigh down the cover andlift the band, causing the cover tocollapse and possibly damagingwindshields, railings or other hard-ware. On smaller boats, you maybe able to hand tighten the band.On larger boats, it’s impossible toget the band tight enough withoutusing a tensioning tool.

Shrinking film is not a job forthe handheld, propane-fired paintstripper sold at hardware stores. Toomuch heat and an uncontrolledflame can result in a cover thatresembles a pincushion. The righttools are worth the investment, par-ticularly if shrink-wrapping is anannual event. What you spend onthe right equipment, you’ll save onthe cost of the film destroyed by thewrong torch. If shrink wrapping isan annual event in your area, con-sider splitting the costs with a boat-

ing buddy or suggest that your clubpurchase the tools.

Dr. Shrink has designed otherspecialty tools that expedite cutting.A film cutter with replaceable bladesand a protective end won’t damagethe gelcoat, graphics, etc. when cut-ting. A ring cutter is a handy deviceto cut strapping and it fits tidily onthe thumb.

Inst a l l a t ion Component sA web of straps and uprights makeup the support frame. Woven poly-ester strapping, preferably 19mm(3/4") wide, joined together withbuckles, comprises the frame. Lookfor heavy-duty strapping that istightly woven and doesn’t break eas-ily when you give it the tug test.

Adhesive-backed tapes, used tosecure folds in the film and accessdoors and repair holes, come in fourwidths and are color-matched to thefilm. Preservation tape has UVinhibitors and it’s ideal for applyingdirectly to the hull, as it doesn’ttransfer a messy adhesive residue.Shrink-wrap tape is less expensiveand commonly used on the film butit tends to break down, much likeduct tape does.

Reusable, padded end caps thatmount over 2x4 posts to preventposts from poking through the cover

are now available. In the past,installers would bundle a blob ofshrinkwrap and staple it to the postbut this padding was inconsistentwith sometimes damaging results.Other options include reusableaccess doors in three sizes and self-adhesive vents, an important add-onto reduce condensation buildup andsubsequent mildew growth. In north-ern climates, vents are placed aslow as possible. On a powerboatthey install close to the gunwales, ona sailboat, close to the deck. Inwarmer climates, vents mount ashigh as possible to eliminate heatbuild-up. Our demo boat neededfour vents; a 15m (50') boat wouldrequire eight vents or more. To reusevents, stick on with double-sidedtape. For maximum airflow, considermounting on the cover a solar-pow-ered vent using double-sided tape.

Gett ing Star te d Dr. Shrink installation and hardwarekits and film are sold at Boat/USand West Marine stores. Three sizesof installation kits, containing strap-ping, self-locking buckles, tape,vents and a recycling bag, fit boatsup to 11.5m (38'). Custom sizes areavailable by special order.

While assembly of the compo-nents is easy, operating the heat toolrequires some skill to ensure adurable, tightly fitted cover. Purchaseextra film and, before covering yourboat, Mike urges that you practicewrapping and shrinking a box ortrash pail, the barbecue, patio furni-ture, garden tractor, whatever. Tooperate the heat gun, open the maingas inlet on the tank, turn on thepilot light on the gun and ignite it.The trigger adjusts the heat from3,000 to a blazing 300,000 BTUs.For better heat control, Mike sug-gests placing a finger or two underthe trigger to act as a cushion toprevent the flame-thrower effect thatmelts the film. Watch the trainingvideo; reread the instructions andpractice until you are comfortable

(above) The key to success is in having the right tools and knowing how to use them cor-rectly. (top right) Dr. Shrink’s handy ring cutter.

with the gun. Shrinking film is similar to rolling

paint on a wall. Start at the bottomand just keep “rolling” it out, mov-ing upwards and side to side. Thegoal is to apply just enough heat toremove as many wrinkles as possi-

ble. Always have a fire extinguisherhandy in case you ignite the plastic,though most times it tends to smol-der. There are also other com-bustibles in the area that can go upin flames. It’s a good idea to wear along-sleeve shirt to avoid singing thehair on your arms.

Design of the frame is critical toprevent accumulation of rain, snowor ice on the storage cover A typicaldesign has one fore-and-aft strap,three or more tied from side to side,three or more vertical posts, aperimeter band and tie-downs (bellybands) for the band located on eachside behind the windshield andtowards the stern. When complete,the objective is to have a frame thatslopes front to back and side to sidewith a 5-pole pitch, like on a houseroof. Smaller boats are often moredifficult than large ones because ofthe shape and deck obstructions,such as fishing boats with rod hold-ers. Cabin cruisers with high aftdecks or flybridge require a morecomplex setup. Sailboats requirethree fore-and-aft straps, one on thecenterline and one on each side,half the distance to the deck edge.Using only one center strap or theboom presents too much unsup-ported material, resulting in lowspots and a loose cover. Sailboatsand boats with more rounded hull

shape also require bellybands at thekeel and then every 1.8m (6’) alongthe bottom.

The support frame, posts andend caps, vents and access doorsare all reusable. When it comestime to cover your boat again, allyou need to purchase is the film, aroll of tape and some webbing toreplace the perimeter band. Todetermine the width of film needed,measure the distance from the maxi-mum height on deck at the center-line to about 45.7cm to 63.5cm(18" to 25") down from the rubrailor just below any graphics plus15cm (6"), at the maximum beam(width) and multiply by two. On ourdemo boat, the band rested 2.3m(7-1/2') from the centerline. Thisallows the film to tuck under theband. Length is measured along thecenterline from bow to stern at thehighest point, adding the extraamount below the rubrail.

Helpful Hint s“Anyone can shrink-wrap a boatcover if they follow a series of logi-cal steps,” says Mike. Skimping onthe materials, using the impropertools or rushing through the jobcauses most shrink-wrapping prob-lems experienced by DIYers. “Using2x2s rather than 2x4s, substitutingpolyethylene rope, which stretches10% or more, for the nylon webbingthat stretches only 2.5% just before itbreaks at 499kg (1100lb) of ten-sion,” explains Mike. “If you don’ttake the time to build a supportframe or make a straight and tightbottom band, the cover collapses.Another problem is too much heat,which causes the shrinkwrap to sep-arate or creates pinholes.”

Plan your frame design onpaper before installing. Whenyou’re ready to shrink-wrap yourboat, wait for a windless day andinvite some buddies to help. Strive toconstruct a cover that is as tight andwrinkle-free as possible so rain, hailand snow just bounces off.


Proper throttle control.


Remove convertible top and bow tonneau cover. Never leave on any covers as they chafe. Moreover, theytrap moisture under the shrinkwrap layer.

Make a yoke at the bow that spans the width plus about 30cm (12"). Tie the ends to side cleats. Wherethere are no side cleats, tie a big loop to the center bow cleat or to the bow eye on the hull. Remove thetwist in the strapping so it lies flat. No fancy knots here; just tie whatever holds. Make a yoke at the stern,again adding about 30cm (12") to the width. String a strap from end to end, tying it to the middle (high-est point) of both the bow and stern yoke.

Measure for wooden vertical supports. This boat has three: one close behind thewindshield to take the pressure off the windshield; one in the bow compartment;and one just forward of the sundeck. Measure distance from floor to centerlinestrap behind the windshield, extending the strap to maximum height. Do the sameat the the bow and stern.

Cut 2x4s to size and push on padded endcaps. Cut two crosspieces of scrap having alength of the distance from the centerline strapto a tie off point on the side plus 30.4cm(12"). If there are no springline cleats, tie to therail or trailer (if equipped) or run a continuousstrap underneath the hull. Line up the post withthe crosspieces. Lay centerline strap in slots inthe end cap and securely staple to cap.

Cut posts for bow and stern supports and attach cross-pieces.

Join crosspieces with a buckle. Remove twists thenthread strapping through the buckle, around andback through and pull as tight as feasible. Cut offends for neatness. Staple crosspiece to the cap.

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Buckles absorb heat sooner than theshrinkwrap and can burn a hole throughthe film. To prevent this, tape buckleslocated near the centerline of the supportframe.

Tape thevent holeon thegas tank

vent fitting to elimi-nate any chanceof escapingvolatile vaporsencounteringflames from theheat gun. If youcannot locate thevent, call yourdealer or the man-ufacturer. Put a strip of tape on the hullbottom directly below the vent as amarker so you can easily locate the gasvent after the boat is wrapped.

Beginning at the stern, thread strapping through the loops, laying it as flat as possible, though a few twists won’tcause problems. Check alignment and adjust loop heights on ties as needed to form a relatively straight line.

Lay the perimeter band above the lower unit sothe cover protects it. Leave extra length, cut theend, install a buckle and hand tighten. Checkthat the band isn’t wrapped around the trailer,jack stands or cradle. Tuck a couple pieces ofscrap film under the band at the corners toallow some slack in the band.

Using the tensioning tool, tightenthe band until you think it’s tightenough, then give it a few moreturns on the tool. It’s tight whenyou can pull out the band just25mm (1") at amidships;absolutely no slack in the band atthe bow.


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Attach ties for the perime-ter band. Measure fromthe rubrail at the highestpoint at the deck edge (the windshield on this boat) to 15cm(6") below any graphics.

Cut two pieces of strapping to lengthand secure each one to cleats on bothsides. Remove twists in these ties andthen make a small loop on the end.Attach ties to each side at the bow andtransom. Tie loops in the ends, also.When sighted, all ties should form anear horizontal line around the boat.The straighter the band, the easier it is

to install the film. Larger boats require an extra two or three loops perside, as do sailboats because of their pear shape.

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Beginning at the stern, drag the filmover the support frame until it extendsat least 15cm (6") below the perimeterband at the bow. Best to unroll in on a

stick or somehow support the film off the groundto keep it clean for it attracts debris through staticelectricity. Unfold the film and tuck it under theband in a few places to temporarily anchor it.

Check that there is enough overlap on both sides and then, using thefilm cutter, cut away the excess 15cm (6") or so below the band.

Pick a starting point (in thiscase the windshield) and, work-ing towards the stern, pull outthe band and tuck the film over-hang underneath. Then go backto your starting point and workforward, tucking the film underthe band.

Form pleats in the film where the hull width begins to decrease (the windshield onour demo boat) and tuck under the band. Do the same on the other side. Pleats arerequired wherever there’s excess film, such as windshields, transom corners, thebow, flybridge, arch, etc.

To shape the bow, grab the film about 15cm(6") below the rubrail and pull it straight out.Cut if off about 15cm (6") beyond the rubrail(deck edge) at an angle that follows theshape of the hull and tuck it under the band.

Depending on the shape of the stern, pull the film back and cut it off 6'below the band. Tuck in the film at the corners, forming small pleats.

Cover any exposed carpet on the trailerwith pieces of shrinkwrap to protectfrom igniting.

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When your boat is ready to come out of storage, cut off the cover just above theperimeter band. Use the film cutter to prevent damaging the hull finish. Gather up thecover and place in the supplied recycling bag. Call UPS and it’s shipped prepaid to Dr.Shrink. Unfortunately, this service is only available in the U.S.

Don’t Trash Your Wrap

Beginning at the transom (ifyou’re right-handed start on thestarboard side; lefthanders starton port.), heat weld the perime-

ter band to the shrinkwrap. Using the heatgun, just lightly touch the film to form a7.6cm- (3"-) high weld. About a second is

all it takes to weld the layers, then follow by lightly tapping the weldedarea with a gloved hand to flatten the film. Go slowly! Be sure a fire extin-guisher is handy. Continue welding and tapping, slowing moving aroundthe bow and down the other side, and around the transom. When com-pleted, if the band was tightened sufficiently, you cannot pull it away fromthe hull.

Securely fasten the perimeter band to the trailer or cradle or attachbellybands where a strap runs underneath the hull to connect theband on each side. (Never tie to jack stands. Any wind that getsunder the cover can pull out a stand.) Our demo boat required two

ties per side: one located behind the windshield, the other towards the stern.Make a small horizontal cut above the perimeter band. Thread a strap throughfrom the back, remove any twist and snug it down until the band is in its origi-nal location. Don’t overtension as you can cause pressure points in the cover.


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Ready to shrink the cover. Sectionalize the cover, pick-ing a starting and stopping point. A good referencepoint is the straps. Shrink from the perimeter band or

from lifelines and rails if equipped, towards the windshield or theboat’s centerline. This pulls all the flab out of the top. Always startat the bottom, never the top. As heat rises and builds up in theapex, it assists in pulling out the wrinkles.

“Herding the wrinkles.”When the film starts toshrink, wrinkles formaround the edge. Usingthe heat gun herd the wrinkles towards the centerline.

Our demo boat was easy as the top was within reach. Larger boats requireusing a ladder, which cancause problems. Should asection cool between laddermoves, it may harbor wrin-kles, which may affect covertightness. If you see wrinkles,apply a little more heat, havesome patience and goslowly.

Obviously, there are wrinkles around any curvesand pleats, but this won’t affect the cover’s tight-ness or durability.

No cover is complete without a hole or two. We didn’t have any, so we fudged one toshow you the repair process. For small pinholes, cut a piece of tape, round the ends,place over the hole and press towards the edges to remove all air bubbles. For a “man”sized hole (refer to photos, top left, clockwise), cut a piece of scrap film that is about 5cm(2") larger than thehole. Lay over thehole and tape allfour sides to thecover. If the coveris cold or wet thetape won’t bond.To tack it down,use the heat gun towarm the adhesiveon the tape. Don’tapply too muchheat or the tapeturns into a gum-ball.

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As the cover cools and heat dissipates, thewrinkles disappear, resulting in a smooth,tight cover. This is proof of a quality film.

Tape all pleatsso they layflat.


To install a self-adhe-sive, two-part vent,remove the backingpaper from the base

and stick it to the cover. Cut outthe center portion, run fingersaround the inside to firmly press

thevent tothe cover, then snap on thecover. Our demo boat usedfour vents: two on the bowand two near the stern, allmounted just above the gun-wales.

Lay the accessdoor flat on thecover and tapearound the

perimeter, smoothing theedges to remove all airbubbles trapped under the tape. If cold or damp, lightlytouch the tape with the heat gun to activate the adhesive.Unzip the door (it has a two-way zipper) and cut out theinside, being careful not to cut through any strapping.

Locate the gas tankvent fitting and cut asmall hole in the filmhere using hook on

the film cutter. Remove the tapeplaced over the vent hole in theinitial preparations, and theneither tape over the small holeor mount a vent. Remove reminder tape on the hull.

Below is the cost to shrink-wrap our demo boat. Note that tools and somecomponents are a one-time purchase and are reusable for subsequent covers. Prices are in U.S. dollars.

Hardware KitDS-789 propane-fired heat gun with 7.6m (25') hose, $315.00adjustable regulator, pair of long cuff leather safety gloves, safety glasses, written application instructions and training movie on DVD.

Installation Kit1 roll 19mm x 91m (3/4" x 300') woven cord strapping, $18.50 10 19mm (3/4") buckles, 1 roll 5cm x 10.6m (2" x 35') shrink-wrap tape, 4 self-adhesive vents, 1 Dr. Shrink Rebag kit

Access Door, reusable, 76cmW x 91cmL (30"W x 36'L) $19.95Other available sizes: 76cmW x 122cmL (30"W x 48"L), 91cm x 182cm (36"W x 72"L)

End Caps 3, 23cm (9") diameter padded $3.00

Posts 3, 2x4sx8' $3.00

Shrinkwrap5.1m x 9.4m (17' x 31') blue 6ml shrinkwrap $37.50Fits boats up to 7.3m (24')

Total shrink-wrapping cost for demo boat (first year) $396.95Total shrink-wrapping cost for subsequent years (estimated) $47.50

DIY BILL

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TOTAL TIME = 2 hours 40 minutes

�


Story and photos by Susan CanfieldIllustrations by Guy Drinkwalter

Tools • Tape measure, 3m & 15m (10' & 50')• Chalk line• Colored chalk sticks• Permanent markers• Tubing bender, 3/4"• Tubing cutter• Drill, 12V 9mm (3/8") cordless• Drill bit, 5.5m (7/32")• Tap, 1/4"-28• Screwdriver, phillips• Socket wrench with 12mm (1/2") deep • socket • Stepladder• Torpedo level• String• Knife• Lead sinker

If you live in an area where boatingis a seasonal activity, covering yourboat for the winter should be a no-brainer. A good cover pays for itselfby preventing damage that occurswhen a boat is left uncovered: gel-coat weathering and cracks, deckleaks and delamination, water-stainedinteriors, corrosion, mildew and rot.Most often, a winter cover is tightlyfitted to the boat to keep the covermaterial from flogging itself to deathin high winds. Often, you can’t workon the topsides when the cover is fit-ted or move around on deck freely.Ventilation under a winter cover isusually limited at best.

Before starting phase two of my22-year-old boat’s ongoing overhaul,I built a working cover frame thatallows unfettered access and excel-lent ventilation. It’s shrinkwrappedextended canopy is tall enough that Ican work anywhere on deck (rein-stalling deck fittings and varnishing)

and wide enough for access to thecaprails (varnishing) and topsides(paint touch-up).

Having used the Kover Klamp(KK) framing system to support myboat’s winter cover for many years, Iknew I could build an extended-canopy frame using the same compo-nents. The greater challenge was tomake the new frame freestanding,since I’d removed my boat’s lifelinestanchions during overhaul. In theend, I accomplished both objectives.The extended canopy, in particular, isa great improvement over the stan-dard boat cover frame and one well

worth the additional complexity andexpense involved. A freestandingframe, on the other hand, is rarelyneeded and adds considerableexpense. It also requires alternativeanchor points (in lieu of lifelineand/or handrail stanchions) so thatthe frame can be secured to the deck.

The standard KK boat coverframe (Figure 1) uses 19mm (3/4")electrical conduit (EMT) held in placewith patented steel clamps (Figure2). It’s like Tinker Toys on steroids!While a KK frame costs more thanone made of wood, it’s far easier towork with, stores compactly and is

REFIT

BUILD A CUSTOM CANOPYA step-by-step guide to building a weather-tested cover that protects your boat from theelements and lets you work onboard sheltered in relative comfort.

(top) When it comes to a weatherproof workingcover, it doesn’t get much better than this. (bottom)White shrink-wrap was my cover of choice. It letsin plenty of light, provides shade from the hot sum-mer sun, and sloughs off rain and snow. If I want towork at night, I can clip a couple of lights to thecover frame and the white shrinkwrap becomes abig lampshade. Note the wood blocks positionedunder each vertical support.

certainly economical in the long run.If a standard frame meets your needs, you can simply

refer to the KK website (www.koverklampframes.com),their printed materials and the instructional video includedwith their boat cover kits. If you’re interested in buildingan extended-canopy frame, that may or may not be free-standing, a “how-to” guide is provided below.

DesignWeather must be the first consideration when developinga design and choosing materials for a boat cover. OnChesapeake Bay, where I live (and boat), winds typicallyrange from calm to 15 knots. Violent thunderstorms canproduce wind gusts of up to about 50 knots. Fortunately,hurricanes are infrequent. One winter, we may get 1.8m(6’) of snow, the next virtually none. I chose a framedesign (60° slope) and cover material (shrinkwrap) thatreadily shed snow and ice. In the event winds over 50

knots are forecast, I’mprepared to removethe cover.

Determine thelength of your frame’s

Figure 1

The author’s 12m (40')extended-canopy frame(overhead view). Rib #1 isaft of the bow, rib #8 is30cm (12") forward of thestern. Pocket braces keepthe ribs parallel with eachother and prevent thecover material from pock-eting between ribs. Thepocket braces extend fromthe first to last rib,halfway between theridgepole and the bend ofthe rib legs.

The standard Kover Klamp cover frame is anchored to a boat’s life-line stanchions or deck railings.

Kover Klamps are designed to hold19mm (3/4") ID electrical conduit(EMT) at any desired angle. A rubbertab between the clamp’s two metalplates grips the conduit, a single boltlocks everything in place. Assembly iseasy with a socket wrench.

Figure 2

Rib #1

Ridges Pole / ???

Between Ribs5'

Gunwale

Skirt

Pocket Braces

Overhang for access/ Ventilation

Rib #2

Rib #3

Rib #4

Rib #5

Rib #6

18"

Rib #7

Rib #8

Figure 3


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stanchions or railings, ribspacing must correspond. Ifadjacent stanchions aremore than 1.5m (5') apart,however, add a floating ribin the middle. If the framemust support heavy snowand/or ice, space the ribs atshorter intervals. My frame,for example, is freestandingwith ribs 1.5m (5') apart(Figure 3). Measure the dis-tance between gunwales ateach rib station. Divide bytwo to obtain the centerline-to-gunwale distance, and

then add the desired amount of over-hang. Record your calculations asshown in Figure 4.

Determine the desired rib legheight. Don’t make your cover frameany taller than it needs to be asheight creates windage, a disadvan-tage when the winds blow. Since I’m160cm (63") tall, a rib leg height of1.6m (63") makes it easy for me tomove about on deck.

Construct ionAn extended-canopy frame is far eas-ier to build on a level surface than ondeck. Lacking a suitable paved areanear my boat, I used a neighborhoodtennis court during the off-season. ButI then had to disassemble, move andreassemble the frame at my boat.Fortunately, the disassembled frameand all its components could be trans-ported by car in a single trip.

Draw the canopy frame in over-head view. Using a chalk line (flores-cent colors work best), mark the cen-terline of your canopy frame on alevel paved surface. With a tapemeasure and colored chalk, markeach rib station along the centerline.Next, draw each rib perpendicular tothe centerline (Figure 5). Put an “X”at the appropriate centerline-to-gun-wale plus overhang distance in both(port and starboard) directions alongeach rib. Use the chalk line to markthe canopy’s skirt. Connect the X’s atthe end of each rib moving from bowto stern, then back along the opposite

side.Assemble the longitudinal ele-

ments. Connect lengths of EMT withKK couplings (standard EMT cou-plings lack the strength needed forframe construction) to form the ridge-pole. With the tubing fully seated inthe coupling, drill and tap the conduitto accept the setscrews (6mm x1.0mm). If you don’t have a metricbit and tap, you can use a 7/32" bitand a 1/4"-28 tap. Ensure that allthe setscrews face in the same direc-tion so they can be oriented awayfrom the cover.

If you’re building a freestandingstructure, you’ll need to separate theassembled canopy frame into self-sup-porting modules for installation ondeck. I separated my boat’s canopyframe into five self-supporting sec-tions: three-legged bow and stern sec-tions, and three four-legged rib pairs(2-3, 4-5, 6-7). Ensure that yourridgepole’s couplings fall whereneeded. If your frame’s vertical sup-ports will clamp to deck stanchionsand/or railings, coupling location isnot an issue.

With the ridgepole (and cou-plings as appropriate) correctly posi-tioned on your pattern, use a broad

Figure 4 Rib spacing and spans. The author’s canopy frame is 12m(40') long; her boat’s length on deck is 11.2m (37')(CL=Centerline).

Station# Distance Distance Plus 18"From Bow CL-Gunwale Overhang

1 1' 25" 43"2 6' 44" 62"3 11' 61" 79"4 16' 68" 86"5 21' 68" 86"6 26' 66" 84"7 31' 55" 73"8 36' 32" 50"

Figure 6

extended canopy. Verify your boat’soverall length on deck (LOD), typi-cally listed in the manufacturer’s spec-ifications, by taking your own mea-surements. Then add the desired over-hang at bow and stern. Example:since my boat’s LOD is 11.2m (37'),and I wanted its working cover toextend 45cm (18") beyond the gun-wales, my canopy frame needed tobe 12m (40') long.

Determine the number of ribs,their spacing and spans. How manyribs will be needed to support thecanopy? If the canopy’s vertical sup-ports will be anchored to the deck

Centerline

Rib station

Rib

Equal distancearcs drawnfrom points A & B

B

A2'

2'

Rib Construction: Place two rib legs onyour chalked pattern. Align the rib archwith its center on the pattern’s centerlinewith the rib legs. Mark and cut the conduitwhere the arch and legs overlap (about20cm/8" above the bend). The measure-ments given here are for rib #1 in theauthor’s frame.

To accurately draw each rib perpendicularto the centerline, first draw short intersect-ing arcs using a string and chalk that areequidistant from two points along the cen-terline. These points must be equidistantfrom and on opposite sides of each rib sta-tion. Finally, draw the perpendicular line(rib) so that it extends through the rib sta-tion and intersecting arcs.


Figure 6

tipped 12mm (1/2") permanent marker to mark each ribstation, circling the EMT. Assemble both pocket braces inthe same fashion, however, you needn’t mark the rib sta-tions. Don’t worry about cutting the ridgepole and pocketbraces to their proper length; just set them aside for now.

Next, assemble the canopy’s skirt. Bend and connectlengths of EMT to conform to your pattern. Remember toposition the couplings for modular installation if you’rebuilding a freestanding frame. Drill and tap the tubing atcouplings. Finally, with the assembled skirt lying on yourpattern, use the broad-tipped marker to indicate whereeach rib leg should land.

Draw the rib patterns. In a clear area, use your chalkline to make a straight line longer than your canopy’slongest rib span including overhangs. This is the baselineused for rib construction. Starting in the center of thebaseline and working in both directions, mark the center-line-to-gunwale (without overhang) distance for rib #1.Next, draw lines perpendicular to the baseline at the cen-ter point and gunwale distances. Then mark your desiredrib leg height above each gunwale, and desired over-hangs along the baseline (Figure 6).

Assemble the ribs. Using a separate length of EMT foreach rib arch, mark the center and bend 60°. Using aseparate length of EMT for each rib leg, mark the desiredheight and bend as needed to fit your pattern (approxi-mately 50°). Placed a pair of rib legs on your chalkedpattern as shown in Figure 6. Then align a rib arch withits center mark on the pattern’s centerline with the rib legs.Mark and cut the EMT where the rib arch and rib legsoverlap (about 20cm/8" above the bend).

Join the rib segments; drill and tap for the setscrews.Again, ensure that the screw heads face inward so theywon’t poke holes in the cover. Repeat this process foreach rib. Use a permanent marker to draw lines around

each rib halfwaybetween its cen-ter and the bendin each leg.These are refer-ence marks forthe pocketbraces that willbe fit later.


(above) Frame assembly on deckrequires a minimum of tools (fromleft): torpedo level, tubing cutter, tapwrench, Phillips screwdriver and socket wrench with 12mm (1/2")deep socket. A canvas waist apron provides pockets for carryingclamps, slide locks, hand tools and a marking pen.(right) TheKover Klamp framing system includes (clockwise from left): pro-tection pads, plastic plugs, rubber tips, slide locks, couplings andpatented clamps.

If you’re building alongside yourboat, it’s time to run a tie-down linethrough each rib. Otherwise, waituntil you reassemble the frame forinstallation on your boat. A one-ounce lead sinker on a string can beused to fish the line through each rib.Before tying a bowline in both endsof each tie-down (where they exit theconduit), slip a length of clear plastic

tubing over the line for chafeprotection. Make sure yourknots are large enough to pre-vent the tie-down loops frombeing pulled back through theEMT. I used 4.7mm (3/16")line that has a breakingstrength of 544kg (1,200lb)and added a rolling hitchabove each bowline.

AssemblyAssemble the canopy frame. Positionrib #1; clamp the end of each leginside the skirt. Use temporary diago-nals to keep the rib vertical. Try to fitthe clamps in a consistent way.Repeat the process for the next rib.Once two ribs are standing, fit theappropriate ridgepole segment abovethe ribs; ensure that the ribs areplumb. As you assemble the canopy

frame, cut and fit diagonal supportsas appropriate (Figure 7). If all fourdiagonal braces for a rib pair are cutto the same length, they’ll be inter-changeable on reassembly.

After clamping the ribs, ridge-pole and diagonal supports in place,clamp the pocket braces under theribs. Bend and fit the bow and sternlegs and attach them to the ridge-pole. Drill and tap for the setscrews.Next, install a wind brace at each ribto prevent the canopy from deformingin high winds. Use a slide lock insideeach clamp to prevent it from slippinginward. If your frame is to be free-standing, you’ll also need to fit acompression post on the centerlinebetween each rib and its wind brace.A post is not needed if the rib hasjust one vertical support.

Label ingBefore disassembling your canopyframe, clearly label its various seg-ments. The KK people sell color-coded and numbered waterprooflabels for this purpose. Take picturesand/or notes for reassembly.

Set UpIf the canopy’s vertical supportsclamp to deck stanchions and/or rail-ings, disassemble the ridgepole,pocket braces and skirt. Don’t disas-semble the ribs. Fit plastic end plugsand protective rubber tips at one endof two lengths of EMT; clamp the tub-ing to opposing stanchions (rubber

tips down). Clamp the appro-priate rib to the vertical sup-ports and adjust rib height asdesired. Repeat this processuntil all the ribs have beenclamped in place. Fit thecanopy’s ridgepole, pocketbraces and skirt. Then mark,bend, cut and clamp each verti-cal support (Figure 8).

Bow

Skirt

Side View

Ridge Pole

Wind Braces (???)

Pocket Brace

Ribs

stern

Diagonals betweenrib pairs

Couplings allowcanopy frame tobe broken into 5sections for instalation

1 2 3 4 5 6 7 8

Skirt

Wood block

AlternatingDiagonals

Vertical Supports

Wind Brace

???? Post

??? Pole (Above Ribs)Cross Section

Figure 7

(above) The author’s extended-canopy frame breaks into five freestanding sections, asshown below, for modular installation on deck.(below) Extended-canopy frame with free-standing supports (cross section view). Frame and canopy tie-downs are not shown.

(top left) My good friend, Tom Kauffman, persevered throughout my frame-building project.Here he’s fitting the final vertical support for rib #7. Notice how the ladder on the left hasbeen slipped in under the canopy frame. There’ll be no need to cut an access door in theshrinkwrap. (above) With the completed frame in place, the foredeck, side decks and cockpitare unobstructed. (bottom left) When setting up the frame on deck, we used sawhorses to holdeach rib pair securely as vertical supports were being attached. If you don’t own suitablesawhorses, make your own using electrical conduit (EMT), Kover Klamps and rubber tips.


Figure 8


each rib. Slip a KK slide lock ontoeach support. After lifting the canopyto the desired height and extendingthe vertical supports, tighten each ver-tical’s upper clamp. Position the slidelock immediately beneath the upperclamp and tighten both setscrews.Then tighten the lower clamp. Repeatthis process for each vertical support.When the center section has been lev-eled at the proper height, mark andcut each vertical support above thepocket brace. Install cross bracingbetween all four verticals supportingthe center module. Finally, secure thecenter module in place by running ten-sioned lines to cleats, perforatedtoerails and/or bulwark scuppers.

Repeat thisprocess with thenext module, build-ing outward fromthe center. As eachmodule is lifted tothe proper level,connect the ridge-pole, pocketbraces and skirt (inthat order). Installdiagonal crossbraces athwartshipbetween verticalsupports. Installdiagonal braceslongitudinally as

warranted by localweather conditions.Install tie-downs toanchor the frame mod-ules on deck to cleats,

perforated toerails, caprail scuppers,etc. These lines must be tensionedwhenever the boat is left unattended.

With all extended-canopy frames,run a tie-down line under the keelbetween each rib’s tie-down loops.These lines too must be tensionedwhenever the boat is left unattended.

Time LineHow long does it take to constructand set up an extended-canopyframe? Under optimum conditions (fairweather, all tools and materials athand, a paved area adjacent to theboat and two assistants), I’d estimatetwo to three days for a 12m (40')canopy. Subsequent set ups, where nocutting or fitting is needed, would takeone to two days. Cost is directlyrelated to a frame’s size and complex-ity (Figures 9 and 10). Caution:Kover Klamps, like Tinker Toys, areaddictive. Once you discover howhandy they can be, you’ll want to usethem to build a temporary garage,workshop or greenhouse. Then you’llhave to buy more when it’s time tocover the boat again.About the author: Susan Canfield is a NAMS-certified, SAMS-accredited marine surveyor inAnnapolis, Maryland. A frequent DIY contrib-utor, she also teaches marine surveying atWoodenBoat School in Brooklin, Maine.

(top) Using a single piece ofshrinkwrap, Dan Hughes(left) and Mike Myers ofGem Polishing, Deale,

Maryland, covered theframe in just twohours. (middle) KoverKlamp’s reusable pro-tection pads are madeof a heavy-duty non-absorbent, non-chafingmaterial. Corner snapsmake the pads easy tofit or remove if clampadjustments need to bemade. Waterproof,

color-coded and numberedlabels, like the one seenhere, simplify framereassembly. (bottom) Withthe cover in place, the author makes final adjustments to thelines securing the frame to the boat. Tie down lines run insideeach rib and under the boat’s keel. Clear plastic tubing protectsthe line from chafe as it exits from the bottom of the rib.

�

Figure 9 Materials required for the author’s 12mLx4.4mWx2.7mH(40'Lx14.4'Wx9'H) boat cover frame. Extended-canopy components are high-lighted in blue, those unique to the freestanding support structure in red.

Structural Lengths Couplings Clamps Slide End Rubber PadsElement Conduit Locks Plugs TipsRidgepole 6 5 8 0 0 0 0Ribs 8 0 0 0 0 0 0Rib Legs 16 16 0 0 0 0 0Pocket Braces 8 8 16 0 0 0 0Wind Braces 8 0 16 0 6 0 16Skirt 8 8 18 0 0 0 0Diagonals/Canopy 12 0 24 0 0 0 0Vertical Supports 14 0 28 14 14 14 0Center Posts 0 0 12 0 0 0 6Diagonals/V. Supports 20 0 40 0 0 0 0TOTALS 100 37 16 20 14 14 22

Figure 10 Cost of materials. (Kover Klamp components are in red)

Frame Component Quantity Price TotalClamps (5/pack) 33 19.99 659.67Couplings (5/pack) 8 6.99 55.92Slide locks (5/pack) 6 7.25 43.50Plastic end plugs (25/pack) 1 5.50 5.50Rubber tips (5/pack) 3 4.95 14.85Protection pads (2/pack) 11 6.50 71.50Electrical conduit (EMT) 100 2.19 219.0019mm (3/4”) x 3m (10')Line, 4.7mm (3/16") braided 1 110.00 110.00(152m/500' spool)Plastic tubing, 6 .14 .846mm (1/4") ID /footTOTAL COST US$1180.78

Bending the vertical supports to con-form to the rib arches enhancesframe rigidity and prevents coverpunctures. Install the wind braces.Don’t forget to label the vertical sup-ports prior to disassembly.

If your frame is free standing,separate the pre-assembled canopyinto modules as discussed above. Liftthe center module into position ondeck. I found it helpful to pre-positiontwo sawhorses (each fitted with pipeholders) on deck. The wind braces ofeach rib pair rest on the sawhorseswhile vertical supports (with plasticplugs and rubber tips fitted at theirlower ends) loosely clamp to thepocket braces and wind brace at

STORY AND PHOTOS By Sue Canfield

Vented loops, also known as siphonbreaks, are essential components inmany marine plumbing systems.They prevent back flooding, due toa natural phenomenon known as thesiphon effect, which can drown apropulsion engine or generator orsink a boat.

The physics behind a liquid’stendency to flow is related to both

gravity and pressure. Gravity causesliquids to flow downhill. However,liquids also tend to flow from highpressure toward low pressure.“Siphon” refers to the ability of a liq-uid to flow uphill through a loopedhose (or pipe) when one end of thathose is lower than the liquid level.The liquid rises inside the hose


because pressure decreases withaltitude and the weight of any liquidin the descending portion of thehose further decreases the pressureinside the rising portion. This siphoneffect can lift water up to a height ofapproximately 9.1m (30'), at whichpoint pressure at the top of the loopreaches zero.

On boats, siphoning is poten-tially a hazard with any hoseplumbed to a thru-hull fitting belowthe waterline, if the other end of thathose is also located below thewaterline. Affected plumbing sys-tems include, but are not limited to:the cooling water injection line onpropulsion engines and generatorswhere the exhaust manifold islocated below the waterline; intakeand discharge lines plumbed to toi-lets located below the water-line; and bilge and sumppumps.

In evaluating the poten-tial for siphoning, be sure to use yourboat’s maximum-heeledwaterline rather thanits static (floating)waterline. ABYC defines maximum-heeled waterline as “the level ofthe water on the hull when the hullis inclined to an angle of 7°, forpowerboats. Many boaters find ithard to imagine thattheir boats could beinclined to that angleand don’t consider thehazard a real one.Unfortunately, manyboat builders subscribe

to the samefantasy.Marine survey-ors will testifyto the damagethey see whena powerboattakes on waterwhile tied to adock andwhen sub-jected to abeam sea or wind action. This“inclined” the boat so that thru-hullfittings installed just above the water-line were, for some time, put belowthe waterline. For sailboats, the max-imum-heeled waterline is at the levelof the sheer amidships. Sailboatsexperience water at this level whenthey are excessively heeled under

sail but other combinations of

MAINTENANCE

waste deck plate

Vent

overboat discharge

intake

holdingtank

Y-valve

ventedloop

12" min

head

A MSD located below the waterline should have ventedloops installed in both its intake and discharge lines. If nec-essary, a U-trap can be used in the intake line near the toiletto prevent a loss of prime at the suction pump due to airbeing drawn in through the vented loop. With electric suctionpumps, a solenoid valve may be needed to close the ventedloop’s air valve whenever the MSD is flushed.

Each of the loops above is intended forinstallation with 19mm (3/4") ID hose (leftto right top to bottom): Wilcox Crittenden,Forespar, Buck Algonquin, and Groco.Before buying, it’s a good idea to disassem-ble several different loops to see how theirvalves work.

ABYC

WITH

MO

DIFIC

ATIO

NS

To be effective, avented loop must beinstalled above themaximum-heeledwaterline, at the high-est point in the hoserun.

UNDERSTANDING

How many vented loops are there on your boat? Where are theylocated? When were they last serviced? If you’ve answered, “What’s avented loop?” or “I don’t know,” read on. Doing so could save youconsiderable heartache and big bucks.

VENTED LOOPS

wind and waves can put the rail down, too. Consider, for example, your boat’s electric bilge

pump system. If the pump and its discharge thru-hull fit-ting are both located at or below the maximum-heeledwaterline (even if only under extreme circumstances), thepotential for siphoning exists and a vented loop shouldbe installed. Unless a thru-hull fitting is well above (e.g.,20cm to 30.4cm/8" to 12") the maximum-heeled water-line, a vented loop is simply cheap insurance in theevent of unexpected immersion due to heavy seas, over-loading or flooding not attributed to the siphon effect.

Inst a l l a t ionWhile vented loops on boats built in the Far East areoften made of stainless steel, those widely available inthe North America are typically cast bronze or nylonreinforced plastic. To be effective, a vented loop must beinstalled above the maximum-heeled waterline, at thehighest point in the hose run. Vented loops preventsiphoning by allowing air to enter the hose and the sys-

tem then pres-sures to equal-ize.

If the ventedloop in anexhaust system’swater injectionline tends to spitcorrosive saltwa-ter all over theengine, replacethe valve with abarbed fitting,then attach ahose that isvented wellabove the water-

line, such as into a cockpit locker. Likewise, if the ventedloop in a waste discharge line emanates foul odors intothe boat, replace the valve with a barbed fitting andattach a hose that’s vented overboard, well above thewaterline.

MaintenanceSince vented loops are typically located behind joineryor at the top and/or back of lockers, they are largelyout of sight and, unfortunately, out of mind when itcomes to maintenance. This can pose a serious problemas the valve in a vented loop can get plugged with saltcrystals and become inoperative. At least annually,check these valves, unscrew and clean. Marine insur-ance companies typically do not pay for damage thatresults from a boat owner’s “failure to maintain.” In theevent your engine fills with water or your boat sinks dueto a vented loop’s clogged valve, your damage claimcould well be denied if you haven’t met your mainte-nance responsibility.

So, if you haven’t already answered the questionsposed earlier, be sure to do so on your next visit to yourboat.

About the author: Susan Canfield is a NAMS-certified, SAMS-accred-ited marine surveyor in Annapolis, Maryland. A frequent DIY contribu-tor, she also teaches at WoodenBoat School in Brooklin, Maine.


From ABYC P-1, Installation of Exhaust Systems for Propulsionand Auxiliary Engines. Whenever an engine’s exhaust manifold isbelow the waterline at any angle of heel, a vented loop (siphonbreak) should be installed in the cooling water injection line.

Maximum heeled waterline as defined byABYC is rail down for sailboats, 7° forpowerboats.

ABYC

7°

GUY

DRI

NKW

ALTE

R

�

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LOW-DRAGPROPS

Follow these guidelines toinspect a folding prop fordamage during the nexthaul out.Story and Photos By Harry Swieca

Folding propellers, often referred toas low-drag, are typically installed onboats whose owner wants to tweakspeed under sail by minimizing dragfrom a fixed prop. Although foldingpropellers vary in blade size, pitchand gearbox ratio, they all have onething in common: under sail the for-ward motion of the boat collapses thehinged blades to streamline the run-ning gear. By minimizing drag in thismanner, you can increase sailingspeed by up to a full knot. You knowwhen a fixed-blade prop is damagedbut it’s not so easy to determine whena folding prop isn’t at its best.

Sure signs that something iswrong with the folding blades includeloss of top speed, poor performancein reverse and excessive hull vibrationwhile under load. Since repairing afolding prop requires removal andconsiderable expense, it’s importantto confirm that the prop is wornenough to warrant the repair.

Examination of the prop begins

with a pressure wash and scraping toclean the entire prop and shaft area.Visually inspect the shaft for corrosionor pitting. If the sacrificial zinc is dis-solved, replace it. Inspect the shaftsupport strut for damage. Move itside to side to see if it’s loose. Graspthe prop and shaft and lift upwardwhile viewing the cutlass bearing (seephoto above). If the clearancebetween the shaft outside diameterand the inside diameter of the rubberinsert is more than 1.5mm (1/16"),the cutlass bearing is worn andneeds replacing. [Ed: For completestep-by-step details on replacing acutlass bearing refer to DIY 2002-#1issue.]

Inspect the prop blades and hub.The hub should be secure with nomovement on the shaft. The bladesshould be void of dents and chips.Close the tips of the blades andgrasp them at the very end. The gapbetween the inside of the blade tips

should be approxi-mately 6mm (1/4”),though this distancevaries with thebrand. If the bladesare touching, theblade stops areworn.

While holdingthe end of theblades, rotate the

tips in a circle. If they rotate, the cen-ter tabs and pins are worn. Finally,open the blades and push them asfar forward as possible. Turn theblades so they are paralleled with thestrut. When viewing from the side,the leading edges of the bladesshould not exceed the centerline ofthe hub. If they do, the blade stopsare worn.

If your prop failed two or moreof these tests, it’s time for a rebuild.Unless you are experienced with fold-ing prop removal and you have theright types of tools such as anextended jaw puller and a very largeadjustable wrench, I suggest commis-sioning a repair yard to perform thejob. If the prop is not removed orinstalled properly, your engine ortransmission could be damaged. Tobring the prop back to original speci-fications, send it to the manufacturerfor repairs. When the prop isreturned, record the new dimensionsfor use as a baseline during yournext inspection.

SA I L B O A TR i g g i n g

Blade clearance between the edges of the blades should be at least6mm (1/4") on a Martec prop. (bottom) The two blades should layparallel, the gap the same at the tip as at the base.

Close the blades and inspect for a gapbetween the inside of the blade tips. Theyshould not touch.

To check for center pin and hub wear, holdthe tip of the blades together and then lift andslowly rotate the blades in a circle.Movement indicates a worn pin and hub.

If the hub and pin are worn the hub will showa gap between the blade core and hub.

54 BoatU.S. Magazine November 2006

Why Outboard-Powered Boats Sink at the Dockclamp, or a cross-thread-ed seacock for the live well to allow seawater into the bilge. At this point, it’s only a matter of time until the bilge pump quits and the boat sinks.

Other potential problems occur with hard-ware-store PVC valves, through-hulls with no sea-cocks, and installations that allow back-siphoning into the live well. A couple of sinkings were embar-rassing — forgotten drain plugs. Tying your drain plug to your boat’s key is an easy way to avoid being red-faced at the launch ramp.

Above-waterline fit-tings accounted for 10% of dock sinkings. Many owners install new four-stroke engines to replace the two-stroke engines that came with the boat, but four-stroke engines are heavier and will force a stern down further into the water — maybe far enough that the self-bail-ing cockpit scuppers are at the waterline. Rain or a forgotten cooler could be just enough to force the scuppers under and sink the boat. Other sinkings were attributed to a leaking jack plate, a missing rigging boot that allowed rain to enter the bilge, and a cracked and leaking scupper. Also, the white plastic transom fittings used for scuppers become brittle and crack in the sun — and cracks in a fitting have the same effect as a small hole in the boat. Bronze or Marelon fittings are immune to the weather and are an easy replacement.

Nine percent of all dock sinkings were caused by poor docking arrangements. In areas with significant tidal ranges and fixed docks, loosely tied boats can get the gun-wale or transom stuck under a dock as the tide rises; the boat is pinned down and the cockpit drains backfill into the boat. Lines must be taut to prevent the boat from mov-ing under the dock but also loose enough to accommodate tide changes. Crossing bow

Damage avoiDance

seaworthy

Any boat can, theoretically, sink in a heavy rain storm. But a recent Seaworthy study found that this is the most common reason outboard-powered boats sink at the dock, accounting for 47% of sinkings.

Here’s why: Most outboard-powered boats typically have low freeboard (distance from the gunwales to the waterline), large cockpits and just a couple of drains aft to carry water overboard. In a heavy rainstorm, water can quickly back up and flood the cockpit, especially when drains are full of gunk. The additional weight then shoves the stern down and water begins to flood back through the drains.

What can you do to stop your boat from sinking in a heavy rain, besides moving to Arizona? For one thing, drains should rou-tinely be cleared of debris (use a water hose with a lot of pressure). The best defense, however, if you think your boat is vulner-able, is to keep water from getting into the cockpit in the first place. Keep a cover over the cockpit so that rainwater (or snow) is directed overboard.

Another 20% of dock sinkings were caused by failed underwater through-hull fittings, the majority of which were plastic. (The latter do not meet the American Boat & Yacht Council standards and were likely added by dealers or do-it-yourself owners. Only bronze or Marelon fittings meet the standards for use below the waterline.) A recent marine insurance claim involved a plastic fitting on a 23-foot fiberglass fish-ing boat that, according to the surveyor, became brittle and broke. The boat itself had been well maintained. The through-hull leaked into a small area of the bilge until the weight of the extra water forced the cockpit scuppers under and the boat sank.

Don’t be penny wise and pound fool-ish. Plastic through-hulls are easily broken and should be replaced with bronze or Marelon fittings. The latter are much stur-dier and the difference in cost is only a few dollars.

A significant number of boats also sank at the dock due to problems with live wells, which are a common feature in fishing boats. Live wells are often plumbed to an underwater through-hull fitting to bring water into the box and sometimes have drains that empty into the bilge (a poor arrange-ment, as anyone with a nose can attest). All it takes is a leaking fitting, loose hose

and stern lines can help. So too can moor-ing whips (flexible fiberglass poles that hold a boat away from the dock). There are also devices on lines or pilings that allow lines to remain taut through rising and falling tides. Chronic docking headaches can almost always be remedied by moving the boat to a larger slip.

Finally, boats that were overexposed to waves at the dock accounted for another 9% of sinkings. Most were being kept at private docks, which are often far more exposed to waves than marina docks. If the boat must be kept at an exposed dock, the bow should be facing open water. An even better alter-native, especially if your boat has low free-board, is a trailer or storage rack.

— By Chuck Fort

Water from the sky—not from below—is the most common reason out-board boats sink at the dock. A partially clogged drain is all it takes to make a boat’s stern heavy enough to allow water to backflow through scupper drains. The best defense (aside from hauling out) is a close fitting cover that directs water overboard.

Subscriptions to the quarterly magazine Seaworthy are $10 per year. For more informa-tion go to BoatUS.com/Seaworthy or call 703-823-9550, ext. 3276.

STORY AND PHOTOS BY Robert Janis

You can replicate the distortion-freesound quality of a home stereo byaugmenting your boat’s existingaudio system. Whether it’s aspeaker upgrade, adding a tweetercombo or a subwoofer or two, ahead replacement that’s satelliteradio ready or a multi-channel high-watt amp. There are myriad possibil-ities depending on your budget andavailable installation space.

Let’s first look at the componentsthat make up an audio system andavailable features. The head unit isconsidered the source unit of the sys-tem. This is where the audio signalis introduced into the system. Headunits include the radio tuner, a CDplayer or cassette player. Most headunits also have the capability of con-trolling a CD changer. More sophis-ticated units can accept a satelliteradio receiver (available from XMRadio or Sirius) or take in audio

from a video source through an aux-iliary input. This permits the additionof a DVD player or videocassetterecorder. Moreover, many moreexpensive head units include somekind of built-in equalizer and low-pass and highpass crossover. Theequalizer portion allows the user toboost or cut particular frequencies tobalance the sound in order toachieve a good sound quality. Thelowpass crossover feeds the low fre-quencies or bass frequencies to thesubwoofers of the sound system. Thehighpass crossover feeds the properhigh frequencies to the speakers thatplay the midrange, midbass frequen-cies and to the tweeters that play thehighest frequencies of a sound sys-tem. Head units that include a radioand cassette player range in pricefrom US$130 to US$240. Units withradio and CD player averageUS$200 to US$400.

Most head units come with abuilt-in, four-channel amplifier topower speakers. This makes it possi-ble to create a sound system withoutan outboard amplifier (explained

The most likely location of listenersshould be considered when mountingspeakers in the cockpit.

If you want superior sound, you need to positionspeakers so to maximize their acoustics and pro-vide the most direct sound path to the listeners. A speaker produces sound when its cone movesback and forth compressing air in waves thatultimately strike the ear drum. The best sound isproduced along a line projecting outward fromthe center of the cones, its central axis. Soundalso radiates approximately 45° from the mainaxis in a pattern that resembles a cone. If the lis-tener is not in this radiating zone, sound mustbounce off of a reflecting surface to be heard.This is not a problem in the cabin below deck butin the cockpit there are few reflecting surfaces.Cockpit-mounted speakers should be positionedin the direct listening path of the occupants.

TIPIn the Zone

Perhaps you are considering upgrading the factory supplied audio system on your boat. Here’s how to design an aftermarket system for a small runabout,mid-size cruiser or large yacht and install electronic components, speakers and subwoofers.

PUMP UP THE VOLPUMP UP THE VOLUMEUPGRADE

later). A built-in amplifier offers aminimal amount of power, perhaps45 watts per channel or enough topower a couple of speaker pairs.Since a boat needs a lot of soundpower to hear the music above theambient noise of wind, waves andengines, the addition of an outboardamplifier would be more practical.

An outboard amplifier takes theaudio signal from the head unit andboosts it, then passes it on to thespeakers. There are one channel,two channel, four channel, and evenfive channel amplifiers available.Each channel feeds power, mea-sured in watts, to one or a series ofspeakers. For example, on a two-channel amplifier, one channel

(top left and right) Examples of coaxialspeakers mounted to the cockpit sides. (bot-tom right) Speaker mounted next to seatsfor maximum sound penetration. Use anadhesive sealant and stainless-steel screwsto secure speakers.


sends power to speakers on theportside; the other channel feedspower to the starboard-mountedspeakers. A four-channel outboardamplifier can feed speakers in fourlocations. Commonly, a one-channelamplifier, also referred to as a monoamplifier, offers power to the sub-woofer or subwoofers. A two-chan-nel or four-channel amplifier usuallyprovides power to the midrange,midbass and tweeter speakers.

Amplifiers are offered with avariety of power ratings, defined inwatts. The higher the wattage, themore the power. Some units haveprotection circuits that shut thedevice off if it gets too hot or isforced beyond its power capabilityand if speaker wires short out.Another protection feature is a sub-sonic filter. This assures that frequen-cies that are too low for a sub-woofer to play are blocked fromreaching the speaker, which coulddamage it. Amplifiers also comewith built-in variable crossovers andbass equalizers. “Variable” means

that the user can set the crossoverpoint between two parameters. Forexample, a variable crossover in anamplifier allows the user to set thelowpass crossover point between 50Hz and 150 Hz. The bass equalizerboosts the bass volume level beingplayed by the subwoofer(s).Amplifiers range in price fromUS$200 to US$500.

Speakers specifically designedfor boats are made of polypropy-lene cones, mylar tweeters andinclude an UV-resistant, high-impactplastic grille with water drainagechannels and stainless-steel mount-ing hardware. A word of caution:as speakers use magnets to producesound, sometimes the magnetic fieldis strong enough to have an effecton navigational electronics and com-passes.

Component sets are available,which include a pair of 16.5cm (6-1/2") midrange speakers and3.8cm (1-1/2") titanium tweeters.Also available are subwoofers andcoaxial speakers, which combine

Ohm is a term that describes the amount ofresistance on the wire that feeds power from theamplifier to the speaker or speakers. The higherthe ohm rating, the more the resistance. Thelower the ohm rating the lower the resistanceand the more power that gets to the speaker.

TIPPowered by Ohms

both speakers in one assembly.Speaker prices range from US$69to US$200.

Many marine audio manufactur-ers offer a remote control. This trans-fers control of the entire audio sys-tem from one unit. Wired remotecontrols range in price from $40 to$200.

Shop AroundThere are three ways to start yoursearch for a shop: contact the audiomanufacturers who offer marineproducts and have them suggest afew dealers in your area; check outthe yellow pages; and the Internet.Products designed for automotive

use can be appro-priate for use onyour boat.Moreover, installersof audio systems incars are familiarwith the harsh envi-ronment a movingplatform can offerand have come upwith skillful ways tosecurely mount and

A bench seat or a stor-age cabinet doubles as agood location for thesubwoofer. (top left,clockwise)To cut thehole, tape or support thewoofer in place andtrace the inner circle ofthe speaker (within themounting frame). Cutthe hole within themarked circle. (far left)More examples of sub-woofer installations.


protect products from the elements.Then there are some of you who

are do-it-yourselfers who may belooking for a project to take upsome time on a Saturday or Sundayafternoon. Those of you who arefamiliar with electronics and installa-tion can buy the equipment from areputable audio specialty store andthen do the installation of theequipment yourself. Visit thestore. It should have marineproducts prominently show-cased on display. Ask thesalesperson about the marineproducts the store offers andhow long the store has beencatering to marine customers.Ask to see photos detailingthe work it’s done on boats.It there aren’t any, move on.Ask if the shop has the capa-bility of having an installertravel to your boat. Manyshops don’t send out theirinstallers to the boat for insur-ance reasons. You may haveto bring a trailerable boat tothe shop to have the workdone. Choose the shop basedon the answers you get andhow comfortable you are withits personnel.

Design Pl anning“Designing an audio systembegins with you making awish list of what you want thesystem to do,” noted IsaacGoren, owner of SoundsGood Stereo and Marine,

Woodland Hills, California. Issachas been involved in the car audiomarket for more than 20 years andhe is a pioneer in the retailing andinstallation of products for boats.

Do you want a head unit thatplays just CDs or do you want ahead unit that plays cassettes andcontrols a CD changer? How loudwill you be playing the system? Doyou want satellite radio? Where doyou want the music heard? Do youwant to control the system from morethan one location onboard?

Issac suggests choosing a headunit or amplifier with a built in low-pass and highpass crossover andequalizer to eliminate the need foradditional outboard components. Afour- or five-channel amplifier, whichis 2 ohm stable (refer to definitionon page 51), is the most efficient.The 2-ohm stable provides enough

UPGRADE

A panel makes a good location for acoaxial speaker.

In this case, the amps are screwed down toa carpet-covered Ozite board mounted in astorage compartment. Notice the wires aretied together with wire ties to assure aclean installation.

A tower is the perfect mount for speakers.These speakers from MB Quart were cus-tom installed in enclosures then mountedon stainless steel brackets that bolt to thetower. All speakers face toward the backof the boat.

A large nook like this one stows the headunit, a speaker and amplifier. The compart-ment is away from water, dry and sealed.Fans were installed to cool the amplifier.

A wired remote control could be mountedjust about anywhere in the boat. This allowsthe user to control the sound system fromthe cabin, not just the cockpit where thehead unit is probably mounted.

Wires should be tied and secured. A very neat job!

Head unit securely mounted. An optional plasticcover fits over the unit to protect it from water.


power to feed energy to the speak-ers through an extremely long run ofwire. With a four-channel amplifier,the front two channels play the midand high speakers with a highpasscrossover and the rear four channels

are bridged to play asubwoofer with a low-pass crossover. Boatswith a multiple cabinsoften need two or moreamplifiers to play speak-ers in the main cabin,aft cabin and masterbedroom.

Walk through yourboat and decide whereto install the compo-

nents. You’ll need tolocate a dry storage area

for mounting the amplifier. Also,check that there is access toroute wires from the amplifier toeach selected speaker mounting.You’ll need to determine the lengthof wire runs from the amp(s) to thespeakers. More important is the

length of the power and groundcables to the amp. This may influ-ence your decision of where toinstall the amplifier. Make a sketchthat shows the locations of all com-ponents, the routing of wires andcables. This way you’ll know exactlywhat you need and where every-thing goes long before you start theinstallation.

If your boat is equipped with asingle battery bank, you should addanother battery. This way one bat-tery is dedicated to engine startingand the other one, a deep cycle bat-tery, to power the audio system,electronics, etc. Some boats mayalso need upgrading to a high-out-put alternator to replenish the extradrain of the audio equipment.

Mo del SystemsYou start with a basic system forsmall boats and then keep building,adding components as the size ofboat increases. For small runaboutswithout a cabin, Issac suggests hav-ing four speakers spread out andmounted as high as possible. Thiscould be a coaxial or midrange withtweeter and subwoofer. Storagearea under a seat or bench is easilyconverted into a speaker enclosureand the front portion cut out toaccommodate the speaker cover. Asubwoofer is commonly installed inthe main cockpit seating area.Many newer boats come with four


Amplifiers are mounted horizontally (or verti-cally) in an area that is dry and well ventilated. Acapacitor (shown on the left) assures that theamps get continuous power. Fuses appear atright.

Speakers can be covered with grille cloth to provideesthetics.

Runabout (no cabin)Head unit with equalizer4 16.5cm (6-1/2") coaxial speakers or 4 16.5cm (6-1/2") speakers withtweeter and mounted to the cockpit sides near seats1 Four-channel amplifier with a highpass and lowpass crossover 1 25cm (10") subwoofer mounted under a seat or bench

Mid-size Cruiser, Cuddy Cabin, Daysailer Head unit with equalizer in cockpit2 four-channel amplifiers in cockpit4 16.5cm (6-1/2") coaxial speakers or 16.5cm (6-1/2") speakers withtweeters placed in the cockpit near the seats1 25cm (10") subwoofer placed under a seat in the cockpit 2 16.5cm (6-1/2") coaxial speakers placed in the cabin1 25cm (10") subwoofer placed in a bench or seat in the cabin 1 wired remote control

Multi-level Yacht Head unit with equalizer in cockpit4 16.5cm (6-1/2") coaxial speakers or 4 16.5cm (6-1/2") speakers withtweeter and mounted to the cockpit sides near seats2 four-channel amplifiers with a highpass and lowpass crossover 1 25cm (10") subwoofer mounted under a seat or bench in the cockpit4 16.5cm (6-1/2") coaxial speakers placed in the cabin1 25cm (10”) subwoofer placed in a bench or seat in the cabin 1 four-channel amplifier mounted on the flybridge 4 16.5cm (6-1/2") coaxial speakers on the flybridge1 25cm (10") subwoofer on the flybridge2 wired remote controls

TIPSample Systems


speakers. So to upgrade, just substi-tuting these speakers with aftermar-ket speakers will be sufficient withoutcutting any holes. A dry place undera seat, underneath the helm or

behind a panel is ideal for mountingthe four- or five-channel amplifier.Where there’s adequate dry storageyou can add a six-disc CD changer.The new head unit likely fits in the

cavity that housed thefactory head unit. If not,you’ll need to resize thehole or reposition on thehelm.

A mid-sized cuddy,daysailer or weekenderwith a cabin has thesame components in thecockpit as mentionedabove for the runabout.For interior sound, add

S o u r c e s

Alpine Electronics800/421-2284; www.alpine-usa.com

Audiovox Specialty Applications800/688-3135; www.asaelectronics.com

Babb800/892-2221; www.babbspeakers.com

Bose800/999-2673; www.bose.com

JL Audio954/443-1100; www.jlaudio.com

JVC 800/252-5722; www.jvc.com

Kenwood Marine Audio800/456-3340

Marine Audio Engineering & Sales800/754-9876; www.marineaudio.com

Maxxima Marine631/434-1200

MB Quart800/ 962-7757; www.mbquart.com

Ocean Equipment949/588-1470; www.oceanequipment.com

Pioneer Electronics800/421-1404; www.pioneerelectronics.com

Poly-Planar215/675-7805; www.polyplanar.com

Prospec Electronics800/394-1914; www.prospec.com

Sony Marine800/ 844-2774; www.cpsdistributorsin.com

Sounds Good Stereo and Marine818/999-4523; www.sounds-good-stereo.com

(above) Sounds Good Stereo installer wires three MB Quart 8-inch two-way coaxial speak-ers on to a side panel of a ski boat. The panel was removed from the boat, the speakers weremounted on it and then the panel was reinstalled (left). That’s plenty ‘o sound mon!

(left) Compartment constructed of medium-density fiberboard covered with fiberglass on theoutside and carpet on the inside to serve as a mount and protection for a CD changer. (bot-tom) A custom panel holds two 6x9 speakers.

a four-channel amplifier to powertwo coaxial or midrange withtweeter speakers mounted on thecabin ceiling, and a subwooferinstalled under a bench in cabinand another one hidden in a pro-tected cockpit locker. Adding awired remote control in the cabingives control of the audio systemthere rather than from the cockpit.

Audio installations on largerboats with several levels are morecomplicated. You’ll have to decidewhether you want each level to bewired for sound. The main cockpitor lower helm station is set up likethe small runabout, the main saloonequipped like the cuddy cabin. Theflybridge typically includes two tofour coaxial speakers and one sub-woofer with a four-channel amplifier.A wired remote control for eachlevel of the boat transfers completecontrol to the user. If your boat hasan AC electrical system you can

include 110-volt homeaudio products in pro-tected areas in the cabinaway from water.

Inst a l l a t ion TipsTools and materialsneeded to perform theinstallation include a jig-saw, drill with bits, stain-less-steel screws and bolts,sealant, marine-gradetinned stranded copperwire and terminals plus awire stripper, crimper, heat-

shrink tubing to guard against corro-sion and heat gun. Cable and wiresizes are based on ABYC recom-mendations and determined by thelength of the run and a 10% voltagedrop. Wires routed through anengine compartment will need to belarger. [Ed: refer to voltage droptables in DIY 1998-#4 issue or theMRT “DC Electrical Systems” CD-ROM.]

Most likely you’ll have to routewires behind a bulkhead, gunwaleor cockpit sides. Use an electrician’ssnake or a bendable rod, referred toas a “fishing tool,” to accomplishthis. Take advantage of access holesalready present, such as drink hold-ers, and remove them as needed.Cutting out the holes for speakersbefore you route wires providesanother access hole for fishing thewires. Bundling wires in split loomtubing, especially in the engine com-

partment, gives a profes-sional finish and helpsguard against heat andwater. Cable tie all wiresso they don’t hang loose.Be sure to include aninline circuit breaker (orfuse) for the head unit andamplifier.

When mounting theamplifier, be certain thatthe heatsinks are properlyconfigured on the top.

Their location on the highest part ofthe amplifier is no accident.Heatsinks are made of metal anddraw out the heat generated fromthe amplifier. Don’t just rely onscrews to hold the amplifier inplace. Instead, mount it to a strongboard, like Ozite or StarBoard thatis then securely screw-fastened andsealed with an adhesive sealant(e.g. 3M 4200). Fashion cleats ifneeded to reinforce the edges. Forcomplete security, thru-bolt the ampto the board.

Speakers need adequate airspace behind them, at least 30.4cm(12") on all sides. As the speakercone (see “In the Zone” on page50) moves forward, it creates a vac-uum behind it. As it moves back, itcompresses air. If the air cavity istoo small, cone movement slows inboth directions. Bass response isalso lost since low frequencies needmore air movement. When speakersare mounted with a huge voidbehind them bass response is furtherdiminished making them soundtinny. In this situation, always mountspeakers in an enclosure.

About the author: Robert Janis is a freelancewriter who has covered the car and boataudio and audio-video industry for more than19 years.


Materials

Cost of materials in U.S. dollars for installing anaudio system (does not include stereo compo-nents):

• Small runabout $100• Mid-size cruiser $425 • Large multi-level cruiser $750

Labor• Small runabout 5 hours• Mid-size cruiser 16 to 24 hours• Large multi-level cruiser 24 to 40 hours

DIY Bill

A CD changer control in a custom-made enclosure andmounted to a cabin bulkhead.

Poly-Planar marine speakers have a low magnetic fieldintensity that reduces interference with navigational elec-tronics and compasses.

�

Marine Equipment InstallationsHere’s how to choose, install and operate equip-ment for your boat includ-ing: air conditioning and heating systems, audio systems, bow thrusters, davits, lightning protec-tion, propane systems,

refrigeration, windlasses and more.

Fiberglass Boat RepairHow to survey, repair and prevent cosmetic and structural damage in fiberglass hulls, decks and transoms. Includes the step-by-step repair

of minor cracks and gouges, large holes, water-soaked decks, delaminated hulls and proper installation of hardware.

Nautical NecessitiesFrom cleaning to fuel filter-ing to waterproofing charts, you’ll find ideas and inspi-ration in this compilation of tips to do-it-yourself boat maintenance, repair and

troubleshooting. Divided into 20 categories to make look up easy.

Better Boats More than 200 do-it-yourself projects. Practical solutions to deck and cockpit refitting, inte-rior renovations, rigging upgrades, space-saving

equipment storage, safety add-ons and other nifty items to customize your boat.

Sailboat RiggingA practical guide to deck layouts, equipment repairs, performance upgrades, rig tuning, sail controls and steering systems.

Building With Starboard22 Projects and Fabrication Techniques: The ideal choice for replacing wood compo-nents onboard – won’t delaminate, rot or splinter and requires no paint.

Plumbing 101A boat owner’s guide to the inspection, mainte-nance, repair, trouble-shooting and upgrading of onboard plumbing systems.

DIY MechanicGasoline and diesel engine service. How to maintain, troubleshoot and repair outboard engines, stern-drives and diesel inboards.

AC/DC Electrical SystemsA guide to expanding, upgrading, surveying and troublshooting your boat’s AC and DC electrical system. All articles follow ABYC Standards.

Painting & RefinishingThe complete guide to painting and refinishing hulls, topsides and decks with marine coatings.

Launch & Haulout How to prepare your boat for spring launch and win-ter storage. Includes lay-up checklists, maintenance and lubrication guides, engine servicing, haulout guidelines, easy-to-build storage covers and more.

Technical CD-ROM Library for Boat Owners

MRT SeriesCDs contain articles from past issues of DIY Boat Owner Magazine

To order call 1-888-658-BOAT or Shop Online at www.diy-boat.com

$19.95each

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A technical reference library for powerboat-ers and sailboaters. The editorial archives of DIY from 1995 to 2007, organized by

year and issue from cover to cover.

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12 of the MRT Series in a custom vinyl case. Power version has Powerboat Rigging and

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Powerboat RiggingFrom gauges to propellers to steer-ing systems, here’s everything you need to know to maintain and repair your boat and trailer, improve boat handling and perfor-

mance, and find solutions to common servicing problems.

UPDATED

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www.diy-boat.com

CRUISE-READYTACKLE

Production boats are not alwayswell equipped to enable boatersto handle and stow multipleanchors and rodes. Here’s howone owner designed, fabricatedand installed an anchoring sys-tem complete with bow rollers,a windlass and anchor locker.

STORY AND PHOTOS BY SANDY TURNEY

After years of reading and research,I decided that I needed two anchorson the bow of “Sandy’s Beach,” myContessa 26, when cruising theBahamas and anchoring with aBahamian mooring. A Bahamianmooring requires two anchors to beset 180° from each other to allowthe boat to pivot when the tidechanges. Since my boat was notdesigned with a bow roller, windlassor chain locker, I had a real chal-lenge accommodating my need.

I had decided on a manualSimpson-Lawrence Anchorman wind-lass with 8mm (5/16") chain gypsy

and capstan. Primary anchorwould be an 11kg (25lb) CQR,secondary anchor a 10 kg (22lb)Bruce, both with all chain rodes. Thedesign needed to incorporate myodd cast-aluminum stemhead fitting,both anchors, Kingston bow rollersfor each anchor and leading all in astraight line to the windlass. Thisrequired fabricating a custom stain-less-steel plate to fit over the stem-head that wouldn’t interfere with theforestay connection points and thatwould hold both bow rollers. Thedesign had to ensure that anchorswould avoid the roller furling drum,the hull and each other when restingon bow rollers. I needed clearancefor kneeling on deck and crankingthe windlass without hitting any-thing. The chain locker below wouldneed two compartments to hold bothchain rodes and it had to include adrain.

Deck modifications included cut-ting off the existing stemhead chocksand reinforcing the foredeck to sup-port the added weight and antici-pated loads of the stainless plate,anchors, rollers, windlass and chainlocker. The design also requiredmoving the bow light from the stem-head with installing a new one onthe pulpit rail. I needed to decidewhere to mount the new bow

chocks, the chain pipe foranchor rodes and theanchor stopper.

Making thePatternUsing the stemhead fitting,which I removed from theboat, and my foredeckmeasurements, I recreated

my foredeck on paper (Figure 1). Iused foam board (available at officesupply stores) to make two-dimen-sional anchor templates to makesure the position and alignment ofthe bow rollers wouldn’t result in theanchors hitting each other and thebow. The CQR bow roller wouldmount on the starboard side of thestemhead with the windlass situatedabout 91cm (3') aft. This providedenough space to kneel on the fore-deck and crank with the winch han-dle. I would mount the Bruce bowroller on the port side at an approxi-mate angle of 20° in order to usethe windlass and not hit the otheranchor and possibly the bow.

Based on my paper design, Icut a plywood template of the stain-less- steel plate. I bolted the bowrollers onto the plywood plate andtook the mock-up to my local chan-dlery to physically experiment with


P R O J E C T S

If you would like to share one of your ownboat-tested projects, send your articles to DIYPROJECTS via mail or e-mail. Include a briefexplanation and photos and/or sketches (don’tworry, we’ll redraw the art). Also, pleaseinclude your mailing address and a daytimephone number or email address. If we publishyour project, we’ll send you between $25 and$150, depending on the published length.

MAIL:P.O. Box 22473, A lexandr ia , VA 22304

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PROJECTS WANTED

BLISTER FACTOR:Indicates the level of difficulty with 10being the hardest, 1 the easiest.

1

9

BEFORE AFTER

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the anchors (I hadn’t yet purchasedthese). I determined that I needed25cm (10") of vertical height so Ididn’t hit the roller-furling drum whenpulling up the anchors. To solve thisproblem, I had my local machineshop fabricate longer link plates(Figure 2). I then dry fit (Figure 3)the plywood plate, bow rollers andmodified stemhead (the machineshop had cut off the chocks) on theboat, to determine the correct posi-tion of the rollers, the plate size andanchor location (I borrowed afriend’s anchors). After adjusting theplate size, I cut another plywoodtemplate. Checking all measure-ments again, I made more adjust-ments to reduce the plate size, andthen cut out a third and final tem-plate. From this, the machine shopfabricated a 9mm- (3/8"-) thickstainless-steel plate with pre-drilledholes for the bow rollers and stem-head bolts. After dry fitting this veryheavy piece on the boat, it wasreturned to the machine shop to drilltwo holes for bolting the assembly tothe deck.

Foredeck ModsTo reinforce the foredeck, I cut outthe ceiling cabin liner and epoxy-glued 12mm- (1/2"-) thick marinemahogany plywood to the undersideof the deck, and then covered thepanel with epoxy and fiberglass.Before glassing in the chain lockerbulkhead, I put the rode dividerinside but left it unattached. I hadnot yet resolved how the rode andchain would fall into the locker. Both

the divider and bulkhead are 12cm(1/2") marine plywood. I made theaccess hole in the bulkhead bigenough so that I could wiggle myshoulders into the chain locker if Iever needed to do a repair to thehull or deck inside the locker(Figure 4).

I covered the bulkhead with avarnished piece of 12cm (1/2")mahogany plywood with a 15cm(6") watertight access port installed.This cover (Figure 5) attaches tothe bulkhead with bolts, washersand wing nuts, which, when tight-ened, squeeze a gasket around thebulkhead opening making it (in the-ory) a watertight seal.

Where to locate the drain forthe chain locker turned out to be amuch bigger safety issue. A friendwas adamant that it not drain intothe bilge as it might flood the boat ifwater enters the hawse pipes.However, I didn’t relish the idea of adrain hole through the hull, espe-cially when the locker floor was atthe waterline. Instead, I installed a19cm (3/4") thru-hull fitting and ballvalve through the chain locker bulk-head with the drain hose snakingthrough the interior to the bilge. Iinstalled a bilge alarm to signalwhen the bilge pump runs because Ican’t always hear it when I’m sailingor running the engine. If there’s a lotof water entering the bilge from thechain locker, I can close the ballvalve.

Back on deck, I filled in the veeportion of the foredeck where itbutted up to the stemhead with solidmahogany strips epoxied together

and chamfered to fit. These aresecured with 3M 4200 and paintedwith white Brightside. I reattachedthe stemhead to the boat with liberalamounts of the same adhesive-sealant and positioned the stainlessplate on top of the stemhead. Alayer of sealant separated the twometals and acted as a barrier layeragainst galvanic corrosion. A stain-less backing plate and four 8mm(5/16") bolts secured both the plateand stemhead. Next, I attached thestainless bow rollers separating themfrom the plate with 4200. Somebolts go only through the plate butmost go through the plate and deckwith stainless backing plates under-neath (Figure 6).

Pulpit stanchion bases wererebed with 4200 and stainless back-ing plates were installed. The AncorMarine two conductor, double-insu-lated 14 AWG wire for port andstarboard navigation lights wassnaked through the backing platesand bases from inside the chain

Projects

2

3 4

5

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locker and into the pulpit tubing. Thepulpit was carefully attached so asnot to pinch the inside wires. I theninstalled the Aqua Signal 40 portand starboard lights with a 22mm(7/8") rail clamp fitting.

Hardware Instal lat ionFollowing the manufacturer’s clearinstructions, the windlass was easyto install. It mounts to the deck withthru-bolts and 28cm (11") diameter,6cm- (1/4"-) thick stainless-steelbacking plate (visible in Figure 5).Overkill? Maybe, but I’d rather over-build than overload the deck.

New stainless chocks aresecured with thru-bolts and a back-ing plate (visible in Figure 5). Theywere placed slightly aft of the centerpulpit stanchions in order that anyline through the chocks would leadfair to either cleat.

Since the windlass mounted out-side (aft of) the bulkheaded area inthe chain locker below to allow thewinch handle to clear the stan-chions, positioning the two chainpipes was problematic. A linedrawn across the deck slightly aft ofthe aft pulpit stanchions in Figure 7shows the area of the chain locker.Rather than the chain pipe entrypassing directly beneath the wind-lass chain stripper, it must carryalong the circle of the windlass and


7


mount on the port side of the chainlocker. This resulted in the Bruceanchor chain pipe positioned onstarboard and closer to the bowrollers so the chain didn’t interferewhen using the CQR. The CQR bowroller’s centerline aligns with the star-board outside edge of the windlass.Adding an anchor swivel helpswhen the CQR comes up upsidedown. An anchor stopper mountsinline with the CQR chain just insidethe chain locker, almost halfwaybetween the anchor swivel of theCQR and the windlass. This stopperacts like a cleat, taking the pressureoff the windlass. It’s thru-bolted witha substantial stainless-steel backingplate.

Fine TuningMy anchoring set up works great(Figure 8). I can release the CQRin seconds by pulling the roller pinthat secures the anchor and the pinon the anchor stopper, thus lettingloose the chain (as I had to do once

on the Intracoastal Waterway). There are some changes I would

make now that I’ve done a lot moreanchoring. First, I would raise thewindlass up about 3.8cm to 5cm(1-1/2" to 2") so the chain, whenstripped from the windlass, fallsmore easily into the chain pipe. Thisinvolves raising the anchor stopperalso. Second, the bow is very heavydue to the robustness of the bowrollers, stainless plate, weight of twoanchors and combined rodes of36.5m (120') of chain. To reducethe weight forward, I plan to removethe Bruce anchor and replace it witha 7kg (16lb) Danforth with only12m (40') of chain and hope it fitsthe existing roller. Removing gearfrom the vee berth will also lightenup the bow, but this means movingstuff further aft and other stuff off theboat.

In RetrospectIf I were to do it again, I wouldhave a single anchor, my CQR, atthe bow. Dual anchors work verywell on bigger boats that can han-dle the weight but my boat’s dis-

placement is only 2,449kg(5,400lb). I would probably install aroller off the stern to hold theDanforth and create a small chainlocker nearby in a cockpit locker.When the anchor is deployed, Icould bring the stern rode around tothe bow. Unfortunately, this limits theuse of the windlass with theDanforth. [Ed: can be done with afairlead system to lead the rode for-ward to the windlass but it wouldrequire using rope rode instead ofchain. Something to consider.] I would also purchase used itemsrather than buying new. This sub-stantially reduces the cost of the refitas I spent way too much money rela-tive to the size of the boat.

Reading and research is good,but nothing beats actual practice. Ihave found that I don’t need twoanchors on the bow of my Contessa26 when cruising the Bahamas, as Ionce thought; one anchor at thebow and one on the stern is reallyall the weight a Contessa 26 shouldcarry.

About the author: Sandy Turney is now cruis-ing aboard “Santana,” her boyfriend’s Chris-Craft 35 Caribbean Ketch. She is waiting outthe 2003 hurricane season taking Spanishlessons and doing boat maintenance inLuperón, Dominican Republic. “Sandy’sBeach” is on the hard in Brunswick, Georgia.

Projects

Prices are in U.S. dollars (2001), tax excluded. Cost of rope rodes is not included.

Kingston CQR-20 bow roller $200Kingston CL-25 bow roller $1402 chain pipes $53Stainless-steel bow plate $40028cm (11") diameter stainless-steel backing plate $402 stainless-steel link plates $100Machine shop labor to remove chocks from stemhead $4019cm/3/4" brass thru-hull, ball valve, hose barb and hose $60Miscellaneous backing plates, bolts, sealant $100Plywood, fiberglass, epoxy, paint, etc. $133Simpson-Lawrence Anchorman manual windlass $550 11kg (25lb) CQR $37010 kg (22lb) Bruce $1502 37m (60') G4 8mm (5/16") chain $21546m (150') 16mm (5/8") nylon rode for CQR NA46m (150') 12mm (1/2") nylon rode for Bruce NAAnchor stopper $55Anchor swivel $55

TOTAL $2661

DIY REPAIR BILL

8

ENGINE SAVER

This monitor prevents overheating when coolingwater stops flowing due to an obstruction.

Garbage bags, seaweed, debris, a worn impeller ormalfunctioning water pump can all restrict the flow ofcooling water to your engine. When this happens, theoperating temperature rises quickly and the damage canbe done before the engine alarm sounds.

This happened to my neighbor’s powerboat whenthe sterndrive became fouled by a bag. The thermalalarm sounded too late to save the engine. I’d heard ofother occurrences and wondered why there wasn’t analarm on the raw-water intake. Wanting to save myboat’s stern drive from a similar fate, I began searchingfor such a device. There are a few available, but onlyone that I considered affordable.

The Engine Saver Kit (US$89) from AqualarmMarine Safety Systems (Tel: 888/298-6206, Web:www.aqualarm.net) consists of a single hard-plastic tube,about the size of a shaving cream can, which mountsinline with the raw-water intake. Operation is simple.Water pushes on a metal ring that disconnects the circuit.Should water stop flowing while the engine runs, the cir-

cuit opens totrigger a reddash light alertand audiblealarmincluded in thekit. You’ll needto purchasetwo 25mm(1"), threadedmale hose

connectors with a hose barb on the other end of thesame diameter as the water hose.

Simple to Instal l Installation consists of three components: the dash lightassembly, the device itself and a wiring harness. Ichoose to eliminate the horn to simplify the installation.[Ed: the “belt and suspenders,” dual alert system pro-vided by the manufacturer is preferred since a light maynot always be sufficient to grab your attention whenneeded.]

Drill a 5mm (3/16") hole in the dash for the bulb.Connect a positive (purple) wire from another instrumentso the alarm is powered off the ignition switch. A nega-tive wire leads to one of the two ground wires on thedevice. Cut the raw-water line somewhere between the


7

hose with all-stainless-steel hose clamps. The other greenwire connects to the boat ground; in my case, theengine block.

OperationTurn on the ignition key and, if all is wired correctly, thered light should shine. Crank over the engine and thelight flickers at idle (700 rpm) but disappears whenadvancing the throttle to 800 rpm, verifying alarm func-tion with every use. With this sensitivity, I’m glad not tohave the horn screeching.

About the author: Dr. Dan McDougal purchased a Parker 25 SportCabin hull and deck with engine installed and completely finished theboat. He uses “Dry Doc” for cruising and fishing Chesapeake Bay.

TROUBLE-FREE HEAD SYSTEM

When adding a holding tank to my head system, Iwanted to design a simple, easy-to-maintain system thatmet all legal requirements.

My criterion for the system was extensive. I wanted(a) freedom from complicated or electrically powereddevices and pumps; (b) holding tank capacity for aweekend for four people; (c) direct discharge options;(d) the ability to lock the system into containment modeto comply in no-discharge areas; (e) both deck fittingand overboard pumpout options; (f) no maintenance,clog-free plumbing; (g) minimal space requirement and,of course, (h) low cost. Of course I started with (a).

No electrics minimizes problems with the marinesanitation device (MSD) and hand pumping decreasesthe freshwater needed for each use. I opted for a namebrand manual toilet, one model I’d already had goodexperience with and knew how to disassemble shouldthe need arise.

As for the holding tank, I choose a heavy wall poly-ethylene unit of the largest size available that fit theallotted space. This system requires that the tank havean opening at the lowest point on one of the end panelsor sides but not in the bottom. It also requires a valvethat can connect any two of the three openings. Somethree-way valves require grinding or cutting off a stop sothe handle revolves completely. (Tee-shaped models usu-ally won’t work because they can only connect open-ings A and B, or A and C but not B and C.) A remov-able or lockable handle is useful for no-discharge areas.Other items include a scoop strainer to fit over the dis-charge hull fitting, sanitation hose or Schedule 80 PVCpipe, clamps, barbed fittings, barbed tee, vent hose,vent fitting, deck plate and Teflon tape and siphon

7

Unit installed in raw-water hose on author’s Mercruiser. Note flowdirection prominently labeled. The author uses colored tape to markthe hoses: green tape for raw-water hoses, blue tape for freshwatercoolant hoses. Wires are behind the Aqualarm, neatly added to thepre-existing alternator (at right) bundle. (top) Warning light ondash.

intake thru-hull and the heat exchanger for freshwatercooling or the intake and the impeller if raw-watercooled but after the water strainer, if equipped. I choose

a location justbeneath theengine block thatruns straight upinto the heatexchanger intake.(The device isslightly more sensi-tive if the circuitcontacts fall verti-cal with gravity.)Cut the hose andremove about20cm (8") or so.Securely threadthe needed hoseconnections ontothe device, usingTeflon tape. MyMercruiser neededhose connectionswith a 3cm (1-1/4") diameterhose barb oneach end. Thebarb ends connectto the raw-water


breaks, if needed. [Ed: refer to article titled“Understanding Vented Loops” on page 46in this issue.]

Instal lat ionAs many boats likely have some of thehead components already installed andusable, for this discussion I’ll presume thatthe MSD is mounted and its intake con-nected with or without a vented loop [Ed:refer to article titled “Understanding VentedLoops” on page 46 in this issue] to anintake thru-hull and seacock. From the MSDdischarge runs a piece of sanitation hose toone of the three ends of the selector valve.Another of the selector valve ends connectswith sanitation hose to an opening in thelower section of the holding tank. A barbed tee inter-sects this hose and the remaining connector attaches tothe deck pump-out fitting. The third opening on the selec-tor valve connects with sanitation hose to the dischargethru-hull, with the opening aft. Finally, the holding tank isvented through the hull topsides or other chosen loca-tion.

OperationIn operation, the three selector valve positions can: con-nect the toilet with the thru-hull for direct discharge; con-nect the toilet with the holding tank for holding opera-tion; or connect the holding tank with the thru-hull foroverboard pumpout (direct discharge). In this position,the boat must be underway to suck out the tank con-tents. Additionally, in the direct-discharge position, thetank can be pumped out through the deck plate.

Fine PointsPresuming you have the resources to complete the instal-lation of the head, plumbing components and holdingtank, some details are worth mentioning.

Use seacocks on all below-waterline thru-hulls anddouble-clamp all hose connections below the waterline.For obvious reasons, position the discharge thru-hull onthe opposite side of the intake thru-hull. Surely, mountthe holding tank vent away from hatches, portholes andthe cockpit even if it means a longer hose run. And runthe vent hose continuously uphill to the vent fitting, ifpossible. Locate the selector valve in a handy place withroom for the handle to revolve completely and beremoved when in a no-discharge area. Limit the dis-tance between the toilet and the selector valve. Shorteris better with all the hoses for that matter. A MSDinstalled below the waterline should have vented loopsin both intake and discharge lines. Holding tanks are

heavy when full so strong mountings are required. Teflontape is great thread sealant but so slippery you mayovertighten and crack plastic fittings, so be careful.

After 10 years of trouble-free use, I can report thatthis system has exceeded all expectations. The system’ssimplicity is always of interest to other boaters whocome onboard and its simplicity and reliability encour-age its proper use.

About the Author: John Brooke is an ardent DIYer based in Centerville,Massachusetts.



BY DAVID AND ZORA AIKEN

After many years of exposure to sunand salt, the exterior frames on plas-tic ports show the inevitable signs ofaging. They yellow or craze orcrack, none of which fits the ship-shape and Bristol-fashion look. Torestore a new look, the port framescan be removed, cleaned andpainted. Better yet, they can bereplaced with new trim frames madeof wood or StarBoard.

Remove the frames carefully soat least one will be intact for use asa template. Naturally, if you plan topaint and reuse them, all mustremain intact. Either way, clean theframe to remove all caulking, paintdrips and accumulated dirt. If yourboat has a wooden cabin trunk, asours does, make new port

frames of teak or mahogany. Wechose mahogany to complement theexisting wood.

Where the new frames are thesame size as the old ones, simplyuse the original plastic frame as a

pattern. If you want a slightly largerframe, as we did to cover theshadow left by the old frames on thecabin side, you’ll need to make anew pattern.

Making a pattern is easy. Millthe mahogany to 9mm (3/8") thick;any thinner and it might crack.Screw the original frame onto thewrong side of the new wood, butnot through the wood. Use twoscrews placed in diagonal cornersand screwed in just far enough tohold the frame in place. Using apencil, trace the inside cutout; thenuse a scribe set to the wider dimen-sion and draw the outer shape.Remove the plastic frame from thewood. Rough cut the inside using ajigsaw (or bandsaw), cutting about

3mm (1/8") or so beyond thetraced line. Cut the outside shapetoo, but cut this on the line. Sand theoutside to a smooth, finished edge.Replace the plastic rim over the newwood. This serves as an accurate

guide as you use the router to finishcutting the inner shape. This is yournew template.

With the new template finished,you are ready to cut the actual portframes. Whether your pattern is theoriginal plastic frame or a new tem-plate, be careful to remove all nicks,burrs, caulking etc. Any irregularityis replicated on the finished frames.Trace inside and outside lines onyour wood, then rough cut eachframe. Use double-sided tape tosecurely “clamp” the template (orplastic frame) to each new woodframe. This serves as an accurateguide to finish cut the shape using arouter and 12mm (1/2") double-fluted tracer bit. Switch to a 6mm(1/4") corner-rounding bit to roundthe outside edges. Sand and varnishto match the cabin trunk or theboat’s exterior wood trim pieces.

A traditional installation uses theoriginal port frames as a guide forthe number and placement of

screws. Drill the screwholes, countersink thescrew heads and use anappropriate wood-to-fiber-glass or wood-to-woodcaulking, such as 3M4200. It’s possible toepoxy wooden frames inplace, rather than usescrews. Use these sameprocedures to manufac-ture these frames ofStarboard. They alsocould be made of alu-

minum, but it might be a pro-ject better left to a local metal fab-

ricator. Aluminum frames are pow-der-coated, or primed and spray-painted with an appropriate coat-ing.

About the authors: David and Zora Aiken arethe authors and illustrators of numerous boat-ing, camping and children’s books, including“Good Boatkeeping” and “Good Cruising”published by International Marine.

RESTORE AGED PLASTIC PORT FRAMES

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