I have a problem keeping the hi-temp stove cement from breaking off around the liner elbow to my Quadra-Fire insert collar. Does any one know if I can tig weld a few tack spots between s.s. and carbon steel (it doesn't seem to be c.i.)? I have a 1/8th" wobble from the insert sitting on a ceramic wool blanket used to seal an old fireplace clean out. Otherwise, I'll need to find a flexible hi-temp sealant (800deg. F). Thanks for any help, C.P.