RE: PROP-JET BINGE
Hi CP- nice thread! Epoxy is great for this kind of work but a little expensive. I have made more lost foam cowls than I can remember so now just make plugs for molds in case more parts are needed. You can use polyester resin in lieu of epoxy but an extra step is involved. To me, the extra step pays for itself because the polyester resin is a lot less expensive. After you carve your foam just 'seal' it with Elmer's wood glue or similar. A couple of coats should do just fine. Let it dry. The polyester resin doesn't penetrate the dried glue seal so your foam won't melt! Then apply your fiberglass matt (for plugs) or cloth (for parts) using the polyester resin just like you did for the epoxy. I always make my foam plugs about 1/4" smaller than needed to account for build up of the resin and fiberglass.