Soooo, JoHark53 what is your past experience with Polyester Fiberglass Resin? Thinning Polyester Resin "A Bunch" with Styrene is really a BAD idea. It Weakens it severly. The resin is intented to Encapsulte the wood to keep water from penetrating. It's not intented to be totally absorbed into the wood. Also,there's approx. 950 cc in a quart of resin. The correct mixing ratio for hardener is 1.5% sooo that means you should add only about 14 cc of hardener. If you added 60 cc. the mix would probably "Kick" off before you could get it out of the container and could potentially start on fire from the chemical reaction and heat generated. As previously mentioned, since Polyester resin cures extremely hard it's pretty much useless without the addition of Chopped strand mat to act as a binder. When used alone when the wood flexes, the resin WILL flex and crack and allow water to penetrate into the inner recesses of the wood. Plywood can only absorb a minimum amount of resin anyway due to the fact that the flat areas of the wood are approx. 1/16" thick and then you hit glue that stops anything from being absorb further into the other layers. The only place where major absorption can occur is on the edges. That's where a concentrated effort should be made to ensure the plywood is sealed correctly.
