> The plans that you buy should be more specific. There are several brands
> of epoxy that are used for boat building. . Some are less expensive than
> others. The brand names mentioned in a previous post should work fine.
> Either buy what is available locally or go for the best price through
> mailorder.

> My question is this: Is Dura-glass a polyester or an epoxy based mix? Most
> auto work is done with polyester based materials. For that matter, most of
> the 'fiberglass' items you see are made with polyester based resin,
> including most 'fiberglass' boats. If you want epoxy, then get epoxy, and
> don't be confused by the other materials on the market. They may be great
> materials, but they aren't necessarily the best for this application.

> Check the plans again. Some boats are simply coated with varnish or paint,
> with paint being the most common coating for the outside of the hull.
> Historically this has been the case.

> HOWEVER Epoxy (not polyester) resin has the ability to soak into the wood and seal
> the surface. Epoxy is also better at resisting water vapor. As a result,
> many people use a process called epoxy encapsulation to completely seal
> all wood surfaces during the construction of their boats. This keeps the
> wood from rotting, and is a great idea for large boats that are kept in
> the water all the time. Small craft that are primarily stored out of the
> water (like most canoes, rowboats, and kayaks) may not need this level of
> protection. If you use epoxy in this fashion you must cover it with a coat
> of opaque paint, or a clear finish that can provide an UltraViolet
> barrier, if the boat will be left in the sun for a long period of time. If
> the designer calls for epoxy encapsulation, go for it! Otherwise, use a
> good grade of marine paint, enamel, polyurethane, or whatever is
> specified.

> Fiberglass gel coat is a form of polyester resin designed as a final
> surface. Think of it as a finish coat for polyester based resins. You
> don't want to consider this.

> Some boats are made from thin plywood panels and need to be reinforced
> with fiberglass cloth and plastic resin. In effect the designer is asking
> you to create composite material that resembles plywood with two outside
> layers of high strength glass and plastic. Again, if this is what is
> called for, do it. Other designers use slightly thicker plywood which does
> not require the additional strength (and cost) of those added fiberglass
> layers.

> Some people put a layer of fiberglass cloth just on the bottom of their
> boats to provide resistance to scratching when the boat is dragged onto a
> beach. If you launch from a dock you might not even need this.

> so, the answers to you questions are: Buy a boat building epoxy, not an
> auto motive one. You may or may not need the glass cloth (it is
> significantly denser than fiberglass mesh, which looks like window
> screening) and if the design does not require the hull to be covered with
> glass cloth, and the seams are well constructed, the painted wood will be
> just fine for many years of use.

> Hope this helps.

> Paul G. Jacobson

Paul,I am using my own plans based on info I have been reading about on various websites. Dura-glass is a polyester based resin with a filler to keep it thick and prevent it from running. I was thinking of using this for the fillets and then using poly-resin and fiber matting to put over the fillets on the inside and the seams on the outside, and coating the plywood with poly-resin gel-coat to waterproof it.

My friend says that the polyester should stick to the wood, but it sounds like this might not be the case. I am also trying to keep the cost to a minimum or I will not be able to aford it. I have several pieces of 1/4 luan that I plan to use. It should be strong enough since I am only going to be on small lakes and ponds.

I can use paint to seal the wood like you suggested, but I am unfamiliar with any resins other than polyester. Byron Lawrence mentioned WEST SYSTEMS, SYSTEM THREE, MAS, and RAKA. Are these plastic resins? What about cost? Thanks for the input,

-Fred