Jolene said..
I think that most silicones ( roof and gutter etc ) will tolerate 150 deg c .
Depends on what your trying to seal up?
I have seen silicone sitting on top of the slag, not burning, in a molten pot of lead when melting down salvaged sheet lead from roofing.
Silicone will do the job, I have seen the blue one sold in auto stores used on an exhaust manifold, lasted well with no problems.
