sealant/cement at firebox to inner adapter pipe?

[grumol]

on my vermont castings dv30 gas direct vent heater(new to me), the manual states that when attaching the inner adapter pipe of the coaxial system to the firebox, i should "run a bead of sealant" at the attachment point -- i'm not clear as to whether they mean the rutland 600 degree silicone sealant(flexible), or the 2000 degree cement(not flexible, with silica)?

 

[DAKSY]

Either one will work.

 

[grumol]

thanks -- i went with the flexible sealant, after reading the opinions of folks in past posts on this forum -- i also contacted vermont castings, but they were zero help, just gave me the usual answer: contact your "local dealer" -- i realized later that i shouldn't have been honest about being a "homeowner", since i assume they were thinking of liability issues -- thats the result of too many folks sueing for the slightest reason -- believe it or not, there are still a few of us out here who aren't helpless "specialists", able to do one thing, and one thing only: their job -- anything else, and they pick up the phone to call another specialist -- last time i hired anyone to do anything was 1970, to tune my '56 vw -- they screwed it up, and out of financial necessity, i got a chilton's manual out of the library(remember those?), did it myself, and proceeded to rebuild many engines over the last 50+ yrs -- from that point on, there was no turning back -- in fact, online has made it much easier to get advice from specialists, like yourself

ok, end of rant -- sorry, thanks for the help