I used JB weld and magic putty, The magic putty did not hold up, but the JB weld did. I just built another one once I actually got a hold of some JB stik, but havn't tested it. I'm thinking maybe roughing up the inside of the coupler or putting some notches or channels inside to give the JB weld something to hold on to might fix the problem. I think the Magic putty, and probably the JB stik gets brittle over time. Either way as long as the JB weld is solid you are still probably protected from shorts.