I only use Great Planes and other well-known brands of 30-minute epoxy such as pictured. You can not use the quickset epoxies on models, the working time is way too quick, that is probably why it won't stick.

You can also use the 12-minute epoxies but I NEVER use anything under that.

These brand epoxies you can only find in R/C hobby stores or online such as Towerhobbies http://www3.towerhobbies.com/cgi-bin...&I=LXK302&P=ML

You can find 30-minute epoxies in hardware stores such as Carr Hardware but they are usually labeled as '2-ton epoxy' and they come in tubes that dispense equal amounts of both the resin and hardener when the plunger is pushed. They work about as well but you don't get as much.

And the CA glues http://www3.towerhobbies.com/cgi-bin...&I=LXPT38&P=ML are CyanoAcrylate that cures instantly, but most have harmful fumes if you don't use in ventilated areas.