Cracked caulking over cab

[dougpatz]

We have noticed that the caulk between the cab and the fiberglass overhang on our Lexington is cracking. What is the best product to use to reseal? Do I remove the old stuff? No evidence of leaks, but trying to avoid a problem.

[bclemens]

I would use silicone. Paintable caulk was probably used and it is drying out.

[dougpatz]

I've been reading old forum posts, and silicone was not advised-only latex. Now, I'm confused. Do I remove all o the old stuff?

[bclemens]

It always better adhesion to remove the old stuff, but not always necessary if you're just going to fill the cracks. Just depends on how much time you want to spend on it.

[grumpy0374]

DO NOT USE SILICON!!! Worst thing you can do. It will be hard as you know what to remove, and nothing will ever stick to it again.
1. get some mineral spirits and clean the old caulk. no need to remove
the old caulk, just clean it.
2. get some acetone and reclean the caulk. It will remove any residue.
3. get a caulk tube of Dicor non-sag caulk and apply it right over the old,
and now clean caulk.

I have a 2012 283ts, and just recently did the same thing to mine. Noticed a few cracks. Cleaned it as above and applied a bead of new Dicor caulk and smoothed it down with a wet finger.
Grumpy

[grumpy0374]

dougpatz, for info Dicor makes two types of caulk, self leveling and non-sag. Both are great products for rv's. Use the self leveling on the roof seams, vents, drip rails, anything horizontal. It will level out on it's own. Use the non-sag on vertical surfaces and seams, like the cap to cab seam.
Grumpy

[Cypressloser]

X2
Dicor only!

[lil2low]

I was told by our dealer that TSP is the best cleaner/degreaser to use because it does not leave any residue when it dries. And then of course dicor lap sealant to reseal like most have suggested.

[grumpy0374]

You want to use TSP, go ahead. Of course thats the same stuff I use to clean my concrete walkway with. No way would I use TSP on a fiberglass cap or painted cab surface. Much to caustic. On aluminum it's much worse. Just go with the spirits and acetone. Will clean it and no residue. A quart of each will set you back a few bucks and probably last you for 2-3 years.
Grumpy

[RonnieTO]

Wow bclemens I'm surprised that you would recommend silicone caulking on a MH rather than a product purpose made for RV's

[bclemens]

In that particular spot, that is what I would use. Roof, no.

The area he's talking about is sealed between the cab & cap, so it's really more for aesthetics.