Case 1. To Build a Production Power Boat

A Production Power Boat

• The boat itself is Length 8 M, Beam 2.5 M, DISP 3200 KG, HP 225 Yamaha Outboard. • What is production?• To mass produce, or to build enough boats that it

becomes an advantage economically• The number of boats built to become economically

viable depends on the method and the tooling outlay• What are the construction options and what tooling do

they require• FRP. Aluminium, Plywood Composite

FRP Production• This is the most common method of building a number of

boats economically• The tooling required are a set of moulds which are usually

female and can be made up of Hull, Deck and Cabin Top, interior structure, and interior liner

• To make the mould a plug is required• The plug is finished to a high standard and the mould is

laminated on the surface of the plug to form a female mould• A very similar process to the lamination of the finished parts in

the female moulds• The tooling (moulds) for this construction technique are

expensive to build, there is a high initial outlay

Aluminium Production• The building of Aluminium production boats is more recent

than FRP and is very successful particularly in the size range under 12 metres

• The success of Aluminium as a boatbuilding material is due to several factors, its strength to weight and the fact that it does not require painting

• Tooling is less expensive than FRP, boats are built from pre cut panel shapes either using C&C router or by hand made patterns

• In this way entire boat kits can be pre cut, fitting together by welding

Plywood Composite• This method of building boats dates back to the 1950’s• The combination of Resin, Plywood, glass fibre and foam has

become the material combination used for one of, or limited production building

• We could really call this construction composite and although plywood is a substantially heavier core than foam it is less expensive and stronger than foam

• The tooling for building boats in this method is probably the least cost although a job lot of patterns should be stored for every boat built

• Because the other two production construction methods are more efficient for reasons we will investigate, plywood composite is more suited to one or several boats

Comparisons of Methods• The outlay in the cost of tooling to build an FRP production boat

means that design alterations can not be considered• The success of a production build relies on many factors such as

careful market analysis, Quality building techniques, marketing of product, and location of the operation.

• Aluminium boatbuilding is noisy, welders are employed along with boatbuilders to piece together the components

• Aluminium boats are most suited to a developed hull (conical development)

• Both FRP and Composite construction allow any hull shape to be built

• All modern factories must provide safe working environment for staff, and the ability to control temperature and humidity to ensure modern products are applied successfully.

Methods of ConstructionFRP• A typical FRP construction will take place in a temperature,

humidity controlled environment• Once the moulds are prepared the laminate process will

either be by hand lamination or by chopper gun• The Gel coat is sprayed onto the surface of the mould and let

to tack off before the laminating commences• The process is quick in Boatbuilding terms• Finished product is generally quite heavy compared to

aluminium or Composite• The product comes out of the mould with one finished gelcoat

surface

Methods of Construction

• Aluminium construction for a production boat is reliant on C&C cut components assembled and tack welded to form the hull, decks, and cabin

Aluminium Construction• Aluminium is a material which is suitable for different methods

to be used to form up the boat• The material itself forms a protective surface when exposed to

UV rays, this means that there is no necessity to paint other than for appearance

• Aluminium is Isotropic

Plywood Composite• This is a very good and proven method of constructing boats,

however it is not as well suited to production building.• The surface of the plywood needs to be protected with epoxy

resin to avoid dry rot, the epoxy must be protected with a 2 pot paint system to avoid UV damage

• This means that there is a large amount of cost in protecting the substrate of a plywood or wooden boat

• On a more positive note wood is light, strong, and the finished article can be superior in finish and performance

• Boats of any design or shape can be built of plywood, timber, foam and glass cloth.

• The modern wooden boat is a composite construction not to be compared with carvel construction

Advantages and Disadvantages

Positive• Any shape of boat can be built in wooden composite style and

new boats can be altered to suit owner requirements and performance improvements

• There is little tooling cost in plywood composite construction• Plywood composite does not have the condensation problems

of other materials• FRP boats are produced quickly with markedly less labour cost

and are rot free.• FRP boats retain their value because there are many of each

design • FRP vessels have market acceptance

Advantages and Disadvantages• Aluminium boats are rot free• Aluminium boats can be constructed as a production boat

without the high cost tooling• Aluminium boats do not need surface coatings except

underwaterNegative• Plywood Composite boats are slow to build, therefore expensive

by comparison• Aluminium boats tend to look commercial when unpainted, they

are prone to Galvanic corrosion problems• FRP moulded boats are not able to be altered to keep up with

modern design ideas, because of the limited life of gel coat there surface finish can break down in a relatively short time

• END