: SO......what will happen if I epoxy over the polyester???
: Should I sand away as much as possible,
: or not worry about it????????

Stitch and glue construction was developed long before epoxy resin was a common item. *ALL* the early stitch and glue boats were built with polyester resin, and many still are. It works well.

When you coat your boat with epoxy you'll cover it with a wonderful waterproofing material. Polyester resin does not soak into the pores of the wood as well as epoxy does, and, on a microscopic basis, polyester resin is very slightly porous, so it does not prevent the intrusion of minuscule amounts of moisture into the wood as well as epoxy does. That is only a concern to people who build boats which spend all their lives in, or on, the water.

Polyester resin comes in two basic styles. Think of them as being either with wax, or without wax. Normally, polyester resin does not harden completely in the presence of air; it stays tacky, which is a nice feature when you are laminating many layers of glass and resin. The final coat of resin would have some wax dissolved in it. As the solvents evaporate and the polyester resins polymerize, the wax is pushed out of the mixture and ends up on the outside sealing the surface of the resin, excluding air, and allowing the resin to completely cure.

You need to roughen up the surface slightly (just enough so it isn't shiny) so the epoxy will adhere nicely. If the polyester resin you used still feels tacky, then it probably did not contain wax, and trying to sand it will be a mess. Varnish it (use a cheap varnish) or coat it with a barrier of lacquer, shellac, paste wax, vaseline, saran wrap-- anything which will exclude air for a few days while the resin hardens. Then use solvents or sandpaper to remove all the sealing materials before you apply the epoxy.

If the resin you used contained wax, then a light sanding will remove any surface residue and you are ready to go.

Good luck with your building,

PGJ