Furnace Vent Sealant

[reno1051]

I had to remove my furnace and due to how my trailer is set up I had to remove the chrome exhaust that was seemingly caulked to the exterior of the trailer.



I have seen some conflicting opinions online regarding what to replace it with. I've read just use butyl tape (which doesnt seem heat rated), high temp silicone (some say never use silicone), plumbers putty, etc.


Whats the safest, most cost effective product to use? Is butyl tape safe despite not being high temp rated?

[Marcm157]

If it were me, I would use Butyl tape under the edges of the trim piece to seal against the outer wall skin and then maybe some proflex around the outer edges for additional water tightness...

[Route 66 Traveler]

Here is a new product to replace the Butyl tape. I just ordered a tube from Amazon, but haven't tried it yet. You could Email Dicor and ask it it would be good for the furnace vent. When I removed my furnace vent last year I re-installed it using the Butyl tape.


https://www.amazon.com/Dicor-Butyl-R...f_=as_li_ss_tl

https://www.youtube.com/watch?v=z2AuLDPxGhQ

[reno1051]

Hmm that rubber sealant looks interesting but i may just go with the butyl tape. My concern was with the temp rating of the butyl tape in a high temp area but i guess it does not matter in this case.

[Marcm157]

Originally Posted by reno1051

Hmm that rubber sealant looks interesting but i may just go with the butyl tape. My concern was with the temp rating of the butyl tape in a high temp area but i guess it does not matter in this case.

The outer edges of the furnace vent that meet the RV wall is not likely as hot as the center exhaust. The butyl tape is really going under those edges.

[Rustic Eagle]

Originally Posted by reno1051

snip.........My concern was with the temp rating of the butyl tape in a high temp area but i guess it does not matter in this case.

Had to remove my furnace and outer exhaust vent assembly back in early 2020 and reinstalled the exhaust vent assembly using Butyl Tape........, no problems to-date.

Bob

[us71na]

Dicor butyl tape is rated for temps to 275 F. I could not find a temp rating for the Dicor 451BSG-1 sealant at the Dicor site.

[Marcm157]

If you touch the outer edges of your furnace vent while furnace is running which is where the sealant would be applied, you will see it is not too hot. I'm confident that butyl tape will be fine.

[reno1051]

I went with the butyl tape as thats what was there originally. Once my replacement parts come in I can reinstall everything and check it out. Thanks for the advice everyone!