The AC quit on me. I haven't figured out exactly what the problem is, but the furnace blower keeps stopping. Thinking the motor was bad, I pulled it. Runs fine on the bench. I let ti go as long as a half hour, and the motor didn't get hot. Removing the motor meant removing a section of vent. It was sealed to the heat exchanger outlet with some white junk. I had to use a torch to get it loose. So what do I reseal it with? I am not sure how hot it gets, but surely too hot for caulking compound. Gasket cement?