sealant for deck to cabin top joint

[rebel heart]

For my teak decks, I use Teak Systems (SIS 440) caulking. For some smaller wood stuff, I use Like Calk.

I'm yanking up the caulking between the coach roof (fiberglass) and the deck (teak). It has seperated in some areas and was letting water in. Now I'm trying to figure out how to replace it properly. I know that I want to put some tape down in the bottom of the seam, so the next time I yank this crap up it will be easier.

The fiberglass is stained black from the previous calking, so I'm worried that even with acetone I won't be able to get a solid bond against it.

Any advice would be helpful; I'm yanking more of the stuff today, but the cabin is going to look like the bottom of a waterfall if I don't get this thing sealed before the next rain.

[rebel heart]

Here's a picture of what I'm talking about. There are some areas where it's wood-to-wood, which Like Calk should be fine for, but the fiberglass to wood caulking portion spooks me out a bit. Just want to make sure I get it right so I don't have to redo this again anytime soon.

[roverhi]

I've used LifeCaulk for forty years without a problem. It's slightly easier to work with than 4200 and really likes to stick to FRP. If it's going to be in contact with teak, wiping the teak down with acetone would be good. The oils in teak affect the bonding of LifeCaulk or almost all caulks, for that matter. You might check with Teak Systems to see what their product is. If it's polyurethane (4200, sikkens) or polysuflide (LifeCaulk, 101) it should also work.

Peter O.
Pearson 35 #108

[SkiprJohn]

Aloha Rebel,
I agree 100% with Peter. Life Caulk is good stuff and should work just fine. Its qualities are that it will flex a bit when needed but still maintain a good seal.
Kind regards,
JohnL

[rebel heart]

Okay, sounds good guys. I'll go with Like Calk. I like what I've seen of it so far, but I wanted to make sure someone's used it on a big seam like the one I'm working with (total distance of maybe 50 feet). Thanks a lot for the help guys.

[rebel heart]

Here's what it looks like when you use the multimaster.

YouTube - Multimaster Removal of Polysulfide

[Wotname]

Rebel H,
Perhas you may already know this but if not, I hope the following is helpful.

Mind you I am not a caulking expert but I have re-caulked a couple of decks over the years. From my experience, it is that little strip of paper (waxed one side, sticky the other) at the bottom of the seam that makes all the difference.

When I put it in, the seam stays caulked for ages. When I leave it out, the caulking pulls away from one side or another within a year or two.

As I understand it, the theory is that the caulking should only adhere to the walls of the seam so that both the top and bottom of the caulking can stretch or compress as required. If it adheres to the bottom of the seam, then as the walls of the seam move, the caulking will fail at the weakest point of adherence which is normally one of the two walls.

[GordMay]

Polyurethane adhesive/sealants, like 3M “5200" & “4200", should NOT be used on teak decks.

Polysulfide sealants, like 3M “101"*, Sikafelx “290DC”, and BoatLife “Life-Calk” are generally recommended for sealing teak seams.
The two-part pourable sealant, like BoatLife “Life-Calk Two-Part Type P” have an excellent reputation.

*3M may not currently recommend ‘101' for teak decks (? Replaced by “Teak/Wood Seam Sealer” ?)

See also:
HOW TO MAINTAIN AND CAULK TEAK DECKS ~ by Andina Foster
http://www.yandina.com/TeakDeck.htm

[rebel heart]

Wotname -

Loud and clear on the "don't let it stick to the bottom" part. The previous job was just poured in let to stick everywhere, so I think I'll try to do it right this time around. Beyond that, I want to make sure that when I go to remove the stuff it should be a bit easier since I won't have to scrape so much off the bottom.

I was planning on just putting some regular blue tape on the bottom, and then sealing over the top of it. I suppose that doesn't really help matters much though, since the tape will stick to the bottom and the caulking will stick to the tape. I could flip the tape upside down (sticky side up), which would certainly keep it from sticking to the bottom horizontal.

Any ideas on a "proper" tape for this? I have a roll from 3M that says it was made for the job, but it's very thin; I need something in the 1/4" - 1/2" range.

[Cheechako]

Although smelly, good old 3M 101 is great for caulking teak/glass. Takes a while to setup, although I'm not sure it ever gets really hard. If you get it done and then it rains, 101 doesnt care if it gets wet before it sets up...

[Wotname]

Originally Posted by rebel heart

.....
Any ideas on a "proper" tape for this? I have a roll from 3M that says it was made for the job, but it's very thin; I need something in the 1/4" - 1/2" range.

AFAIK, 3M makes that tape in several widths from about 1/8" to at least 3/8". However I have only used 3/16" and it is the only stocked locally (but is the big wide USA, all should be available ).
Good luck, it is not the nicest job is it.

[rebel heart]

I found it: 3M 218 tape. Of course there's one that's too wide, and one that's too narrow. The narrow one would be best, but I might use the too-wide, and cut it down (yep, slowly but surely) to size.

From what I understand this can make the difference of the seam lasting for 10 years or 2, so I'll take the extra hour and make the tape nice and pretty.

I'm getting better at this caulking thing: it's getting less and less horrible.