J-B Weld might be disappointing in this case in that it has a max
temperature of 500? F.

Years ago I fixed a dime sized hole in a cat. converter with JB Weld, 3 1/2
years later the repair was still holding-that's when I sold the vehicle.
I'd try JB Weld. YMMV, but it worked for me.    Jeff

Jeff Stewart
fonman4277@earthlink.net
http://autos.groups.yahoo.com/group/vwcampersmidatlantic/