I have had one [censored] of a time fixing an exhaust leak from my crossover pipe. First it was the gasket, now after getting a used crossover it’s coming from the joint where the flange meets the pipe. I won’t tighten it any more due to warping of the flange so I went the JB weld high heat epoxy putty route. It’s my first time using it so I didn’t actually knead it into a ball, I flattened the stick out and kept folding it over on its self until the two parts were mixed and a nice grey color. I prepped the surface prior with engine degreaser followed by brake kleen, then used 60 grit sand paper to rough up the surface. As I was pressing and molding the putty in place it began snowing. By the time I was done it was in the low 30s and still is 16 hours later. I fired it up this morning and I could still hear the exhaust leak, and after 30 seconds the putty patch went from solid rock consistency back to putty and was malleable. I’m reading online it needs double cure time in temps lower than 50 degrees F. However after 16 hours, 8 of which I used a work light which burns your hands after being on 30 minutes to try and quicken the curing process, some areas are still malleable. So did I knead incorrectly or is it too cold for this stuff to cure?