3M Marine Sealants for Campers

HMS Beagle wrote:


Most of the products sold in the RV outlet do not have this problem as they conveniently remove themselves at regular intervals. If you like leaks and maintenance, they are the way to go.

lets use some common sense here. yes, don't use 5200 under skylights, roof vent covers, objects that you may need to replace. Do use it for permanent repairs where indicated.
bumpy

5200 is hard to remove, but not impossible. I would not use it on something you are likely to need to remove in the future - but it can be done and is no worse in this regard than a few products I have had to deal with on RVs.

4200 is quite a bit easier, as is 4000UV.

Most of the products sold in the RV outlet do not have this problem as they conveniently remove themselves at regular intervals. If you like leaks and maintenance, they are the way to go.

5200 is a permanent option designed for a below the waterline install. I cannot imagine it's ideal for any RV application. But to each is own.

I used 5200 on my shower and kitchen sink drains, replacing the original plumber's putty that had begun to leak. No regrets.

With many years in the marine business, my experience is do not use 5200 on any surfaces you may have to separate in the future. I would say it's not an RV material.

edatlanta wrote:
It was mentioned above that 5200 was hard to remove. I would say it is virtually impossible to remove without severely damaging whatever it is cured to. One time, on a boat, I needed to remove a failed through hull transducer. It actually had to be cut out. Somewhere I found a product that was supposed to dissolve 5200. It didn't.

I would caution against ever using 5200 on an RV unless whatever it was attached to can be easily removed and replaced because the 5200 definitely isn't.

X2!
While I think the 4200/5200 products are some of the best on the market, I cannot imagine using them or the other marine adhesives on an RV. Most leaks are likely to be in the roof area or roof penetrations. Things like skylights, vents, covers, etc need to be periodically replaced. Having them glued down with 5200 would almost insure a major battle/damage removing them.

It was mentioned above that 5200 was hard to remove. I would say it is virtually impossible to remove without severely damaging whatever it is cured to. One time, on a boat, I needed to remove a failed through hull transducer. It actually had to be cut out. Somewhere I found a product that was supposed to dissolve 5200. It didn't.

I would caution against ever using 5200 on an RV unless whatever it was attached to can be easily removed and replaced because the 5200 definitely isn't.

The 3M sealants under discussion are not surface joint sealants and should not be used as such. Spreading them over the top of cracks in already failed joints will have little lasting effect (nor will any other sealant). On a proper lapped joint, the 3M or Sika polyurethanes and polyethers are superior in pretty much every way - other than cost - to those commonly sold at RV outlets. That is why they are used on boats where leaking means sinking, more than a mere inconvenience.

The 3M products are used to seal the joints of thru hull fittings going through the bottom of boats. Sealing properties are critical there. I have used both 3M products on my boat for years with excellent sealing results.

The 3M products mentioned are, IMO, adhesives first with sealant properties. I don't think I'd considerate as a surface joint sealer.