: For what it is worth, I once asked a chemical engineer at G2
: epoxies how to tell if epoxy was good (assuming for the moment
: that the issue if resin crystallization has been dealt with by
: heating, as described here by others). I was using the epoxy for
: guitar construction, and needed to be certain that the glue I
: was using was good in the long term. He advised me to mix a
: small sample up according to the standard ratio, let it set
: completely on some sort of plastic surface from which it can
: easily be removed. Once it is set, peel it off the surface to
: check it. If the set epoxy is hard and clear, you are good to
: go. The key is the clarity of the set epoxy. As I understood
: him, if polymerization is failing significantly, the epoxy will
: set up somewhat cloudy. By clear, I am not talking about color,
: just clarity. For example, good red wine, even the dark red
: stuff, is still clear.

You want it transparent, not translucent :)

Bill H.