Antique: I used the stuff DA sold me (flux coated), but I'm sure its no different than the high temp silver solder sold at Home Depot. I was worried about the temp as well, but you have to get the metal red hot before this stuff melts... I hope the exhaust never gets that hot, if it does, I think the solder melting would be the least of my problems. I got about 15 flights and 10 ground runs on the exhaust pictured above, total about 20 hours of run time, most of that header is cowled, good flow in the air to cool, but not much on the ground runs - to date, no evidence of melting and no leaks. I'm no welder by trade, I've sweated a few copper water pipes, this was my first hack at the high temp stuff... brazing... soldering... <shrug> I melted the flux coated stuff in the joint thingy, using a torch I bought at Home Depot, and its all holding together nicely It was like playing Monster Garage.

Roger