Mixing in a container with a wax lining (or waxed paper) is asking for trouble. The wax will often inhibit if not prevent a good cure. You can also get in trouble by trying to thin the epoxy with alcohol. I know some get by with it but also have seen many where the cure will never harden or cure well. Best to use a finishing epoxy or it you must thin, use acetone. Best is to use no thinner at all and gently heat the joint if you need better penetration or spreading.