3M Marine Sealants for Campers

Different principals.
Rv panels are sealed between the joints, while you don't have loose joints in boating.
I agree that most of RV is using the cheapest stuff they can find on the market.
Look at bathroom faucet. Even Section 8 housing would not allow such.
If you take a look at new RV - they don't have sealers on trims. Usually they come on later, when factory seal behind turns junk.
The sealers sold by Camping World are pretty good. I can't compare them to 3M, but when I am at Camping World, I will not seek marine sealer.
Thanks for the tip anyway.
If I can find them on the net for good price- I will definitely order some.
EDIT fond them for $16 in West Marine. Lot of reviews about nozzles coming apart. This is not 3M I remember from the past.

I mention these 3M sealants frequently in appropriate threads.
bumpy

I'm sure you know that 5200 is a very strong adhesive making later removal difficult if that is a consideration. 4200 is weaker but still much better than anything in the RV store.

I certainly agree. I never used them in a marine application but have used both on my TT. I never knew of 4000UV, however the other two stay whiter than any other RV specific sealant.

Definitely the 5200 I haven’t had a leak since I started using it. Check out West Marine. They have it on sale from time to time. I got the last batch for 11.99 for the 10oz caulk tubes. (And no I don’t work for them)

I'm also involved in the boating world, and don't use anything else on my camper. No one on a boat would ever use the junk they turn out for RVs. The 3M sealants are expensive, and the RV industry is cheap which might explain some of it. They can also be very messy to use for the inexperienced.

I'm sure you know that 5200 is a very strong adhesive making later removal difficult if that is a consideration. 4200 is weaker but still much better than anything in the RV store. My favorite for most roof sealing is 4000UV - this is actually a polyether, not a polyurethane, and is more UV resistant (mainly it does not yellow in the sun), with about the same bonding strength as 4200.

A quick search revealed several discussions about 5200.

I'd like to use something else next time I need to reseal. I'm done with Geocel Proflex. It turns hard and yellows, and mildew grows in/on it.

I am also from the boating community and use 4200 for most of my add-on mods that require sealing. Holds up fine on fibreglass panels and adheres very well to the rubber roofing. I prefer the 4200 as it is more elastic than the 5200.

I think the RV community does not defer to these products mostly because they don't know about them. Sikaflex is also a great sealant for these applications.