[BRENT in 10-uh-C]

Originally Posted by SAJ

According to the SDS for JB weld extremeheat it is not an epoxy but a sodium silicate (water glass) putty containing steel fines. A single pack product containing water and finally set by heat after drying.
This makes sense because no epoxy can withstand more than about 260 deg C (500 deg F)and Extremeheat claims 1300 deg C (2372 deg F) which is white heat - way above red heat (about 550 deg C)!
The downside is water glass is brittle and has poor adhesive properties. It is not "sticky" like epoxies
SAJ in N Z

Have you actually used the ExtremeHeat product??