Greg, I have not run into any epoxies that contained wax. Not saying they aren't out there. What I have seen is epoxies that have been applied in a relatively thin laminate or coating and cured at below optimum temps. What happens in this scenario is that the epoxy does not crosslink completely and the solvents tend to rise to the surface. This leaves a gummy surface that is a bit like wax. In this situation you are correct that polyester would never properly cure on such an epoxy surface. IMO 90% of epoxy issues are either poor mixing practices, either not correct ratios or simply not mixed well enough. The other is that in most cases epoxies need at least 70 degrees for 12 hours to get to max strength. Even if cured at 70 degrees for 12 hours it will continue to cure for up to a week. For this reason I post cure all my fiberglass fuselages and when I sheet foam wings they are cured at 100 degrees for a minimum of 12 hours. I know this is all asking a bit for the average hobbyist you excluded of course ( your reputation precedes you ) but with a little additional effort those of us doing glass work are able to work faster and make stronger parts with less bulk. Oh and if you do have some epoxy glass work that comes out with a slightly gummy surface, simply wipe with acetone to clean those solvents off and expose to an elevated temp for a few hours ( I sometimes throw things in my car and let them bake in the parking lot at work ). One thing I will agree with is it is my policy to not use polyester over epoxy. Like Bob, I really don't like the stuff to begin with.