I'm afraid I need to join the Brodak Breakers club too. Kersplat on pavement and the muffler and half of the rear muffler lug went sailing. I tried JB welding the broken muffler itself and also the lug area on the engine. Lasted about three seconds after I started the engine. I did clean the broken aluminum surface what seemed like really well. I could try JB Welding a stud on the threads where the lug sheared away, but not confident it would adhere any better. Anyone have success with JB Weld on aluminum?