Sealing Through Hull Fittings

[jray]

I'm getting close to rigging and fitting. After oversizing the through holes, filling and re-drilling what sealer is recomended for bolt holes and around the chain plate exit.

[slowpoke]

Hi Jon,
I've used 9200 before, but it cures to a pretty hard consistency. There's also 7200, it cures up a bit more flexible. Both of these are 3M products, and come in a tube. I've seen 9200 for sale at Home Depot for a couple bucks less than at west marine.

[Kevin]

I recall being advised to avoid 3M 5200 marine sealant because it pretty much becomes permanent. Therefore, I used the slightly less 3M 4200 marine sealant. It stays flexible and seemed to work just fine during last season. I did remove a few things and didn't have any problems with getting it off when I wanted to.

I got it in a small tube at HD and it was much cheaper then worst marine. I basically saved up all of that type of hardware installation stuff and did it one day because the stuff does cure up and I figured it wouldn't save on the shelf very well. I also found that a little goes a long way.

Good luck. This is the fun part

[jerome]

What about Sikaflex ? Heard a lot about the stuff down here.
http://www.jamestowndistributors.com/us ... e+Overview

seems to be a good product.

[jray]

Thanks everyone, is seems as many options are available as there are products. Narrowing it down helps lots and yes I am going to enjoy this part of the build. As soon as I can get her back right side up.

[slowpoke]

Ooops!! I gave you the wrong numbers! Thanks Kevin for giving out the right numbers for the 3M stuff. Shows you how long it's been since I did any of that.

[Chad]

I've heard good thing about Sika, but never used it. You generally don't want to use polyurethanes since they are such strong adhesives. Sika's 291 looks like a milder version, so may be OK. I prefer polysulfide, such as Boat-Life's LifeCaulf (I think it's called) or 3M's (might be the 4200 that Kevin listed, I don't recall). Never use silicone, unless the part you are sealing has a plastic that is incompatible with polyurethane or polysulfide, such as polycarbonate or acrylic/plexiglass.

The polyurethanes and polysulfides are MESSY. Mask what you can- ideally both the deck and the edge of the part, and have several rolls of paper towels handy, and not a bucket, not a trash bag, but a trash bag in a bucket to receive all the dirty towels. The bag must be held open! Trust me on this.

[jerome]

Hi all,

İ need some advice on how and where to use that Sikaflex or 3m stuff.

As recommended by everybody, 100% of all hardware holes on my boat were pre drilled, filled with epoxy/silica and redrilled.
Now, when bolting down a piece of hardware, let say a clam cleat, do İ have to use the sealant ? İf yes where exactly, just inside the holes were the bolts will go through or also underneath the part itself as if it were regular glue (that would be in between deck and part bottom surface) ? Or do İ bolt the thing down without any sealant , than make some type of a fillet around the part?

İ am for instance fixing my mast foot base and my bow piece. Both are heavy duty pieces of stainless steel wich will be bolted through. Where exactly would you guys recommend using the sealant ?

Sorry to bother with such simple questions but İ am really not too sure of what İ should be doing...

[jray]

Jerome I started out applying the sealant to the mounting holes. That was messy as most all of it pushed through when the screws or bolts were pushed in place. What I ended up doing was putting the fittings together with the mounting screws and placing the sealant on the screws before pushing them through the mounting holes and securing with washers and nuts. Caution, a little sealant goes a long way and try not to get it anywhere you don't want it. It is tough to clean up both before and after it sets.

I don't know how to advise you on gluing down the fittings themselves. I did on some like the deck cleats and other hi load fittings but didn't use any extra on the camcleats or sheet turning blocks.

[jerome]

That helps a lot. İ was pretty much thinking along the same lines. Glad to hear you did the same.

[jerome]

Pretty amazing post, thanks ! İ just wished İ had such a clear visual guide for building everything else !
İ will stick to the Sikaflex 291 which İ bought already.Plus they say pretty good things about it in that post. And İ really dont want the hassle to try to find anything slightly new or different here in Turkey. İ am glad İ found Sika !