Caulk for exterior

3X Here for the Proflex...it's some of the best sealant I have used and it is what the RV manufacturers use for those also.

3X Here for the Proflex...it's some of the best sealant I have used and it is what the RV manufacturers use for those also.

Butyl tape and Lexel caulk.
In a quick fix moment, I put some Lexel over silicone that had pulled away between trim and the camper. I went back to it a couple weeks later, to properly fix it, and the Lexel was definitely adhering. So, I left it.
More than a year later, it’s still good.
Maybe some things will stick to silicone.

I use butyl tape under anything mounted on a vertical surface and then seal the edges with non-sag or non leveling dicor. It's how most campers come from the factory so I think it's a good solution.

Dicor non-sag sealant.

Another me to for the ProFlex

Pro Flex Rv Flexible Sealant by Geocel. It is for RV's and remains flexible. You can buy it online or at a dealership. Ace Hardware used to carry it in white, clear and black.

Another choice would be OSI Quad. You can get it at Lowe's and Home Depot and it comes in different colors. It does pretty well on trailers and I believe it is a polyurethane based caulk.

Do not use silicone. The sun destroys it, it is very hard to remove and nothing else will stick to it not even more silicone. It seems to work down into the pores of the material that it is applied to leaving the surface with a slick feel. This is at least my experience with it.