ZENTHANE®

Patent #4304706 MIL-DTL-53039C

Single Component Aliphatic Polyurethane Coating, Chemical Agent Resistant (CARC)

GENERAL HANDLING PROCEDURES AND OPTIONS March 2009

ZENTHANE® Patent #4304706

MIL-DTL-53039C Single Component Aliphatic Polyurethane Coating,

Chemical Agent Resistant (CARC)

General Handling Procedures and Options

Table of Contents DESCRIPTION .............................................................................................................................. 1

GENERAL ..................................................................................................................................... 1

MILITARY USE AND SYSTEMS ......................................................................................... 1 - 2

HANDLING PRECAUTIONS ................................................................................................ 2 - 3

APPLICATION METHODS ......................................................................................................... 3

AGITATION PRIOR TO AND DURING USE ............................................................................ 3

FLUID DISTRIBUTION AND DELIVERY SYSTEMS ....................................................... 3 - 5

AIR LAW COMPLIANCE AND REDUCTION OPTIONS .................................................. 5 - 6

SPRAY SUGGESTIONS ........................................................................................................ 6 - 7

SAFETY ........................................................................................................................................ 7

STORAGE, SHELF LIFE, TRANSPORTATION ..........................................................................7

DRY TIMES AND CURE ............................................................................................................. 8

RECOAT, TOUCH-UP, PATTERN PAINTING ........................................................................... 8

FILM THICKNESS AND COVERAGE ........................................................................................ 8

CLEANUP AND FLUSHING ........................................................................................................ 9

PACKAGING ................................................................................................................................. 9

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DESCRIPTION ZENTHANE® is the trade name for a family of moisture cured, single component, aliphatic polyurethane coatings formulated and manufactured by Hentzen Coatings, Inc. ZENTHANE® Camouflage CARC Coatings conform to all of the requirements of MIL-DTL-53039C and can be used as an alternate to MIL-C-46168D. ZENTHANE® CARC Coatings are formulated to be free of lead and chromate. Type I are formulated for application as packaged with a maximum of 420 gm/liter (3.5 lb./gallon) of volatile organic compounds. Type II and Type IV are available with VOCs as low as 1.0 lb./gallon. GENERAL The purpose of this Technical Bulletin is to provide general guidelines for the proper handling and application of ZENTHANE® CARC Coatings. ZENTHANE® CARC Coatings differ from dual component materials in that no catalyst component is required just prior to use and they do not have a limited "pot life." ZENTHANE® CARC Coatings curing mechanism also differs from the dual component system. These unique coatings chemically cure when they react with moisture from the atmosphere. Therefore, caution must be taken to avoid contact with moisture prior to final application. Be certain to read the section covering handling precautions. Because ZENTHANE® CARC Coatings can be used under numerous conditions, we are not able to cover all situations in this Technical Bulletin. Please contact our CARC Technical Group on any questions or areas not covered in this bulletin. MILITARY USE AND SYSTEMS In most cases ZENTHANE® CARC Coatings are used as the topcoat portion of a military coating system (i.e., MIL-T-704J), which normally consists of the following segments:

• Cleaning and pretreatment of the substrate prior to painting (i.e., TT-C-490). Hentzen 02110GVP Wash Primer conforms to DOD-P-15328D and can be used when an organic

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pretreatment is required. Priming with a two-component epoxy primer (i.e., MIL-P-53022B, MIL-PRF-23377J, or MIL-P-53030).

Hentzen 05510WEP-X White Epoxy Lead and Chrome Free Primer conforms to MIL-P-

53022B and can be used on either ferrous or non-ferrous substrates. We also have approved high solids, 3.5 lb. VOC/gallon, 04488WEP-4, and 2.5 lb.

VOC/gallon, 03848WEP-HFX, that are available if compliance to air pollution regulations is a requirement.

• Topcoating with ZENTHANE®. This could be either a single color system or a

combination of camouflage colors as a designated pattern. HANDLING PRECAUTIONS Moisture Contamination: Although ZENTHANE® is very similar to conventional single package coatings, it is more sensitive to moisture contamination. Therefore, care must be taken to prevent moisture or moisture laden atmospheric air from coming in contact with the material during storage and handling prior to application. During mixing operations, excessive moisture coming in contact with the material will begin to increase the viscosity and can eventually cause the material to gel. Material left in partially filled containers can skin. This is caused by moist air filling the empty head space and curing the top surface of the coating. This skin can be removed and the remaining material used. Skinning can be eliminated by two methods. The first would be a "solvent float" using the proper urethane thinner or solvent. The second would be a nitrogen (N2) purge and blanket. Solvent Contamination: Care must be taken to use only recommended solvents for reducing and flushing purposes. Many solvents can contain large amounts of water, which will cause viscosity increase and possibly even gel the material. Use only urethane grade solvents such as 00053SST-1 for these purposes.

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Alcohols and Glycol Ethers or thinners containing these solvents (such as epoxy thinners) must not be used with ZENTHANE® or other polyurethanes as they will adversely affect the cured film properties. APPLICATION METHODS ZENTHANE® is normally applied by spraying, but it can be brushed for touch-up or on small areas. ZENTHANE® can be applied by conventional air atomization, airless, HVLP or air assisted airless spray guns. ZENTHANE® can also be applied through most electrostatic equipment. ZENTHANE® does not require heat to be applied, but material temperature should be in the range of 75oF or higher for proper atomization. See section on spraying suggestions regarding the use of paint heaters. AGITATION PRIOR TO AND DURING USE ZENTHANE® CARC Coatings are heavily pigmented and therefore must be thoroughly agitated or mixed prior to and during use to insure complete pigment dispersion. We recommend paint shakers for five gallon and smaller containers. For drums we recommend drum rollers. Other forms of agitation can be used, but freedom from moisture contamination must be considered. FLUID DISTRIBUTION AND DELIVERY SYSTEMS ZENTHANE® can be used in most of the common fluid distribution and delivery systems currently used in industry with little or no modification. Listed below are the most common systems along with precautions and recommendations:

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• Pressure Pots: Must be equipped with agitators and the material kept under constant slow agitation.

It is important that dried air be supplied to all pressure pots just prior to entry. This can

be accomplished with a very efficient and well-maintained extractor and/or desiccant device.

The ultimate system would be to pressurize the pot with commercial dry Nitrogen (N2). The fluid hose should be kept full at all times and normally flushed thoroughly after each

days use. If fluid needles are properly seated and the material is held full in the fluid line, the

material can be left in the line without flushing. To insure that the lines are full, positive pressure must be maintained on the pot at all times. An alternate method would be to valve the fluid outlet at the pot. Closure of this valve - when not in use - assures a full line.

We further recommend that the agitator be run slowly and continuously at all times. This

will insure pigment suspension and avoid any skinning possibility.

• Pumping Systems: ZENTHANE® can be pumped to single or multiple stations with paint pumps designed to handle materials of this viscosity and the abrasiveness of CARC Coatings. If the material is to travel any distance or be left in the line over extended periods of time, it should be re-circulated to avoid settling. We strongly recommend that the lines re-circulate through the pump and not back to the holding tank. This will insure full lines at all times.

Air operated pumps should not be placed on top of the holding tank. During operation,

moisture condensation forming on the pump could potentially find its way into the holding tank and ultimately contaminate it with this moisture.

Holding tanks and drum covers should be designed so that empty headspaces contain

only very dry air or nitrogen (N2) to eliminate any moisture contamination. Holding tanks should be slowly agitated at all times. This is to insure proper pigment

suspension and eliminate any skinning possibilities.

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If an air operated mixer or agitator is used, we recommend that an extension be added to

the exhaust pipe that will bring the end of the pipe well past the holding tank. This will prevent the possibility of exhaust moisture entering the holding tank.

• Siphon or Cup Guns: The larger delivery type guns can be used for painting small

areas and for laboratory use. Use of the lesser delivery type guns may require some reduction. We suggest a steel 1/2" ball be placed in the siphon cup for agitation. AIR LAW COMPLIANCE AND REDUCTION OPTIONS ZENTHANE® is designed to comply with 3.5 lb. VOC/gallon or less air regulations, but can also be used in areas where these regulations do not apply. These areas are as follows:

• Areas Requiring Compliance @ 3.5 Lb. VOC or Less: ZENTHANE® can be sprayed as packaged in the container without reduction through most standard spray equipment. If reduction is required in areas where VOC compliance is an issue, “exempt” solvents are available. Contact a member of our CARC Technical Group for recommendations.

To spray ZENTHANE® without reduction, the material temperature should be in the

range of 75oF or higher. At lower temperatures the material becomes more viscous and proper atomization becomes more difficult.

Heaters can be used, but care must be exercised so that the material is always moving and

never exceeds 120oF for any period of time. For more information on heaters, please refer to section on spraying suggestions.

• Areas Without Air Law Restrictions: In these areas, ZENTHANE® can be reduced with recommended urethane grade solvents if desired.

For most applications using MIL-DTL-53039C Type I material, we suggest a 20 - 25%

reduction with our 00053SST-1 (medium evaporation) ZENTHANE® reducer. Types II

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and IV should be reduced with exempt solvents. In some instances such as the finishing of very large equipment or in other special

situations, it may be advantageous to contact our CARC Technical Group for other reducer recommendations.

SPRAY SUGGESTIONS Listed below are suggested starting points for the various types of spray applications. These starting points are based on ZENTHANE® being used without any reduction and at a material temperature of 75oF. If reduction is used, downsizing of nozzles and lower pressures could be used.

• Air Atomizing Spray - Pressure Feed: o Fluid Hoses: 5/16" I.D. minimum o Fluid Orifice: .050 minimum o Fluid Delivery: Horizontal stream prior to breaking the plane o Air Cap: Corresponding to fluid orifice o Atomizing Air Pressure: 60 - 70 psi

• Airless - Air Assist Spray: o Fluid Hose Size: 5/16" I.D. minimum o Fluid Tip Orifice: .015 minimum o Fluid Pressure: 800 - 1,000 psi o Air Pressure: 25 - 40 psi

• Airless Spray: o Fluid Hose Size: 5/16" I.D. minimum o Fluid Tip Orifice Size: .015 minimum o Fluid Pressures: 1,000 - 1,200 psi

• Electrostatic:

ZENTHANE® can be applied by most electrostatic systems. If reduction is desired, use

Hentzen's 00053SST-1 or contact our CARC Technical Group for further information.

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• Heaters:

Heaters can be used effectively in the temperature range of 90oF to 100oF, but the

material must be kept recirculating at all times. The heat transfer device should never be in excess of 120oF.

Heater systems that do not pass the material in direct contact with the heat transfer device

are preferred. Contact us for further information. SAFETY ZENTHANE®, like all paint and coatings, contains ingredients that can be hazardous if not used properly. Be certain to read all warnings and cautions on the containers and the Material Safety Data Sheets prior to using. MIL-DTL-53039C states, "The Surgeon General requires airline respirators to be used unless air sampling shows exposure to be below standards, then either chemical cartridge respirators or airline respirators are required." STORAGE, SHELF LIFE, TRANSPORTATION ZENTHANE® will remain very stable for a minimum of eighteen months if stored below 80oF. It is our recommendation that this material be stored in a cool, dry area and never in direct sunlight. At temperatures above 80oF for any extended periods, the material may tend to increase in viscosity which will affect application. Caution should therefore be exercised when transporting ZENTHANE® in trucks and trailers for extended periods during extremely hot weather. Temperatures of 120oF or above for any prolonged period of time will adversely affect shelf life. DRY TIMES AND CURE

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The following dry schedule can be expected from Type I material at ambient conditions of 77oF and relative humidity of 35%:

• Set Time: 15 - 30 minutes • Dry to Handle: 2 - 3 hours • Dry Through: 3 - 4 hours • Excellent Acetone Resistance: 70 hours

At ambient conditions above those listed, the drying times will be reduced. Conversely, at ambient conditions below those listed, drying times will be extended. Air movement and exhaust in the drying areas will reduce drying times. Force drying ovens operating in a temperature range of 120oF to 220oF will markedly reduce drying time. Contact our CARC Technical Group for further information. RECOAT, TOUCH-UP, AND PATTERN PAINTING ZENTHANE® CARC Coatings can be recoated at anytime during and after the curing cycle. They may also be applied "wet on wet." ZENTHANE® CARC Coatings can be touched up or repainted with themselves at anytime without sanding. The surface however should be free of oil, grease, dirt, moisture, etc. ZENTHANE® is for pattern painting due to its excellent overspray blend in properties. FILM THICKNESS AND COVERAGE To obtain proper camouflage properties, MIL-DTL-53039C states that camouflage coatings be applied to a minimum dry film thickness of 1.8 mils. Coverage (sq. ft./gallon @ 1.8 mils) for each color is listed in the Technical Bulletin for the specific ZENTHANE® product. CLEANUP AND FLUSHING Cleanup should be prompt and before drying or curing begins. ZENTHANE® has excellent

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solvent resistance after curing. Recommended solvents must be used for flushing and purging to eliminate moisture contamination. Use Hentzen's 06340SST, 00053SST-1 or urethane grade ketone type solvents for best results. PACKAGING ZENTHANE® is normally packaged in one and five gallon containers. Special packaging arrangements can be provided.