RE: epoxy on epoxy?
Don''t know if things have changed, but back when epoxy was just getting popular, it was common knowledge that it would bond to either epoxy or polyester resin. And that polyester resin wouldn''t bond to epoxy.
The reason everyone cared about that was that when you were trying to patch something, if it was regular glass or you didn''t know if it was polyester or epoxy, you knew that epoxy would work.
Just some extra info on the topic.............