Interesting on the Devcon failing your tests? I know in general the 5min epoxy doesn't take as much heat as slow cure stuff. I use the slow cure stuff for all the heated grips I put on quads and sleds for customers. But allot of people use devcon for bedding rifles ect so it would be interesting what kind of failures your experiencing. I just use the 2 part slow cure epoxy from the local hobby store(9oz) Works great for knife handles, and when mixed with finely chopped fiberglass mat makes a great high strength filling material(great for bedding rifles)