Leakage through base rail fittings

[trflgrl]

What product and process should I use to stop moisture from finding its way down the screws in base rail fittings? I'm imagining removing the screws and filling the holes with something like caulk, then re-setting them, as I could do that one or two fittings at a time and let them dry, rather than taking the rail off completely and turning it into a really big job.

Water isn't pouring in--there was evidence of moisture when I got the boat, and one time when we washed it I could feel dampness around a few of them. We have a covered slip and aren't out in the rain much, but if a small effort will make a big difference, I'll put it on the to do list!

Thanks for any suggestions!

 

[Lazy Daze]

Yup - you got it. Be sure to concentrate on the underside of the screw head, just before it seats. If you can remove the screws from a few bases at once, you might be able to lift the base enough to also squirt some sealant between the base and the boat. FYI, a plastic sandwich baggie works great for tight areas. Squirt the sealant into the baggie, then cut the corner off to make an appropriate sized hole - usually just a very small hole for what you're doing. Think "cake icing bag". The worst part of this whole thing is cleaning up the sealant that squishes out - so use enough, but not too much to limit the squish. This will be entirely "trial by fire".

 

[mistercomputerman]

Some folks say that butyl tape is the best choice.

[video=youtube_share;4Upksj19lyU]http://youtu.be/4Upksj19lyU[/video]

 

[trflgrl]

Yup - you got it. Be sure to concentrate on the underside of the screw head, just before it seats. If you can remove the screws from a few bases at once, you might be able to lift the base enough to also squirt some sealant between the base and the boat. FYI, a plastic sandwich baggie works great for tight areas. Squirt the sealant into the baggie, then cut the corner off to make an appropriate sized hole - usually just a very small hole for what you're doing. Think "cake icing bag". The worst part of this whole thing is cleaning up the sealant that squishes out - so use enough, but not too much to limit the squish. This will be entirely "trial by fire".

Funny the analogy you use, because I'm pretty good with a pastry bag and probably would sacrifice a couple of nice decorating tips to avoid a blowout!
Any particular product you recommend if I go this route?

Some folks say that butyl tape is the best choice.

[video=youtube_share;4Upksj19lyU]http://youtu.be/4Upksj19lyU[/video]

Network is blocking access to that site right now but I should be able to view it later--thanks!

 

[rondds]

These fittings are thru-bolted and probably have aluminum backing plates. Your solution works if you can get to the nuts on the inside to loosen and then re-tighten.

This is what I had on the underside of a bowrail fitting from my '89 340DB.

 

[trflgrl]

These fittings are thru-bolted and probably have aluminum backing plates. Your solution works if you can get to the nuts on the inside to loosen and then re-tighten.

This is what I had on the underside of a bowrail fitting from my '89 340DB.

We can get to a lot of the nuts, but I think I found one or two that are impossible or nearly so. Tedious work and a two person job for sure....likely the reason nobody's bothered with it. I'll probably give her a good washing and then check how much moisture gets through each fitting so I can choose my work load carefully!

 

[rondds]

The fittings on a friend's '99 330DA were leaking. We took some panels off the inside of the boat to find that several nylock nuts were never tightened. Not likely they vibrated down 3/4" on the threads.

Mine weren't leaking but the tack welds broke on the first four on each side (from the bow back). I was able to replace 3 on each side. The 4th were inaccessible so I had a welder re-do them. NOT easy to get to these things and involved disassembling quite a bit of interior stuff.

 

[Lazy Daze]

I do think that butyl is the "best" choice overall. But in your case I think a normal sealant would be easiest especially since you're really just looking to do it a little at a time and not remove the whole thing. You really only need to elevate the stanchion base an inch (or less) to quirt some stuff in there. Don't be concerned about the longevity or reliability of a good sealant - it will still last a couple decades. There's any number of quality sealants out there - my personal favorite is the Boat Life products. LifeSeal, in this case. They have excellent customer service, too.