Caulking for exterior vent for furnace

[The Eyesore]

I just replaced the core to my suburban furnace and now I’m at the stage where I’m installing the vent cover on the outside of the van. The old vent appeared to have plumbers putty beneath it as caulking. The installation instructions just suggest to caulk it but don’t suggest the product to use. I have silicone caulk and I also have plumbers putty. What’s the standard for this application?

[Detroit80]

Don't ever use silicone on an RV. When you need to reseal it in the future, you're going to be hating life as new silicone won't stick to old silicone, and old silicone is a real bear to completely remove. Scraping the "bead" off is stupid simple, but you're going to have a thin film of silicone left behind on the body that needs to be removed as well. You'll also find that if you need to touch up a missed spot, virtually nothing will stick to the silicone.

The standard fare is butyl rubber tape, and just under the edges of the outside trim plate.

If you prefer to use a caulking type product, get ProFlex RV.

[The Eyesore]

Thanks so much! I'm glad I asked!