With polyester resin selling for $15 a gallon or less this would be a lot cheaper than varnish, too.

While the polyester is resistant to UV, I don't know how good of a UV-blocking filter it is, or how well it will protect the underlying epoxy. It sounds like they add something to the epoxy to make it UV resistant, too. it would be nice to know what this stuff is, and where it can be obtained. Can you find out?

Polyester doesn't like to cure completely when it is in the presence of air. There are two main varieties of polyester resin. The big difference is that one already has the wax added to it. This is usually the material that is applied last. The wax migrates to the surface as the resin hardens, and eventually covers the surface -- blocking off air and allowing the resin to cure to a hard, sandable finish.

Not everyone uses both varieties of resins. Some people use the polyster resin and wax mix for everything. afer the first coat cures they have to sand off the wax before applying another coat of resin. If you are living in an epoxy resin world, this is the equivalent of removing an amine blush from a hardened epoxy before puting on another coat.

Some people use the non wax material for everything -- thus saving on sanding between coats -- and then either spray on a barrier coat of mold release (Polyvinylalcohol or PVA I believe) or they cover the resin with plastic (like Saran wrap) or they vaccuum bag it.

Hope this helps.

Paul G. Jacobson