When bedding with epoxy, I use a thin film of axle grease. This has worked for me very well since the early 70's. For the thinner products like Acra-Glass, their little bottle of greenish release agent has worked just fine. I use Pleistocene(SP?) putty to fill in screw holes or other places I do not want the bedding to migrate into. The release agent dries to a thin plastic skin. With just a barrel, cellophane or saran or shrink foot wrapping will also work well, if kept tight.