Best Sealant for Stays

[bluewhaleCA]

I found over the winter that my recent purchase leaks a lot. Mostly from the wires that hold the mast up ( stays? ) This has created rust trails through the inside of the cabin down to the bilge area where I have to pull it out or else it 'rains' in my boat every time I visit. Causing me to mop the ceiling. I'll probably laugh about it one day.

ho ho. ha ha.


Photo's attached. I plan to chip out/clean these tie down areas then prep if possible with a bonding agent then apply a sealant. Does this sound the proper way to approach the problem? Any suggestions as to the product(s) to use?

Thanks!


Paul

[markpierce]

I'm sorry you purchased a boat with such poor design.

Stay fastenings belong outside the hull and not through a deck.

[Misiu]

You probably have to remove the fittings (one by one) clean it and re-bed it. Butyl rubber or polysulfide caulk are products of choice. Search for it on this forum. There are number of posts re re-bedding.

[minaret]

Those would be shrouds, attaching to chainplates. If you have so much rust occuring that it is staining your hull in a streak you almost certainly need to replace the chainplates. I wouldn't put any sail up until you've pulled the chainplates and made sure they are solid or replaced them. If one fails you will probably lose your rig. You can have new ones machined for surprisingly cheap. Re-bed with 4200 UV. Also look for rot in the knees or bulkheads that the chainplates are attached too.

[roverhi]

If you've got that much water coming in through the chainplates, you need to check for rot in the bulkheads or knees that they are bolted to inside the boat. The chainplates certainly should be pulled and checked for crevice corrosion. Reinstall them using a good marine caulk like LifeCaulk, 5200, or Butyl. If the holes through the deck that the chainplates run are too tight, there will be not enough caulk to hold the seal as the chain plates move in service. You may have to open up the slots to a 1/8" or so wider all around than the chainplate. Just adding sealant around the chainplate won't work because it has nothing to bond to and will be too thin a layer to seal. In no instance use sillycone on this or anything else on the boat unless it's the only sealant that will work like on some plastics. Sillycone is wicked wicked stuff that belongs in boobs not boats.

Stainless suffers crevice corrosion when an electrolyte (water) is introduced in an oxygen depleated environment. Just below the deck on chain plates is a prime place for this. You cannot see the corrosion because it is hidden in the deck or behind the chainplate against the bulkhead. It can cause the chainplate to fail catastrophically under normal stress and you lose the rig.

[Exile]

Can someone give me an example of a polysulfide caulk? The term is used a lot on this forum but I'm not crystal clear on which products it refers to. At one end of the spectrum are the adhesive-type sealants (e.g. 3M 5200, 4200), and on the other I gather is your basic marine silicone. Is BoatLife & Boat Seal, to name just two examples, considered polysulfides? Am I in the ballpark here?

bluewhaleCA -- sorry to hear about & see your leaking issues. I agree the amount of corrosion looks like trouble.

[roverhi]

LifeCaulk and 3M 101 sealant are polysulfides. 5200, 4200, Sikkens and other sealants are polyurethane. Butyl is butyl rubber typically used in automobile window sealant and usually available as strips of caulk though it does come in tubes.

4000, BoatLife, BoatSeal are hybrids and may contain some sillycone. There are a few plastics like the one at least one port manufacturer uses that will crack if you use polysulfide or polyruethan sealant so you are stuck. My solution is not to use anything on a boat that requires other than the poly---- sealants.

[Exile]

Originally Posted by roverhi

LifeCaulk and 3M 101 sealant are polysulfides. 5200, 4200, Sikkens and other sealants are polyurethane. Butyl is butyl rubber typically used in automobile window sealant and usually available as strips of caulk though it does come in tubes.

4000, BoatLife, BoatSeal are hybrids and may contain some sillycone. There are a few plastics like the one at least one port manufacturer uses that will crack if you use polysulfide or polyruethan sealant so you are stuck. My solution is not to use anything on a boat that requires other than the poly---- sealants.

Back to the OP's question, since sealing vs. adhesion is the goal where the shrouds connect to the chainplates on deck, would not butyl tape or a polysulfide like LifeCaulk be preferable to 4200? I have a similar set-up on my boat except that I have small SS deckplates that cover the attachment points. There is no need for adhesive in my mind since they attach with small screws. Just need to keep the water out, and potentially be able to do it all over again when/if they resume leaking. I gather the problem with either the adhesives or the silicone-based stuff is that it's difficult to remove all the residue if it has to be redone. Did I get this right?

[minaret]

Lifecaulk pretty much sucks compared to 4200UV. It cracks when exposed to sunlight. And I've seen it fail too many times.

[bluewhaleCA]

Detailed advice. Thank You one and all.

I bought the boat, my first owned boat ( ship? ) 1 year ago as is. The prior owner didn't do any maintenance: He lived 4 minutes from the boat: just walked down and barely managed to get the outboard to get him to an area to raise sail and he was off. The batteries died 6 years ago, as he never found a way to charge them.

So it's my learning project. Other problems have kept me from taking it out since I bought it. Now I'm desirous of getting some time in before winter comes and thus looking to start on repairs. I'm learning the parts of the craft, one by one as I fix them.

Here my main question is stoping the water intrusion. However I have noticed the area of the cabin top/deck where the cables attach as being 'weak' looking.

Thus far I've had very little luck in finding repair firms who will work on the boat. So I end up doing most things myself, learning as I go.

Think I'll go back and take one apart if possible. Then see what I can find for a replacement. I believe there are 4 shrouds: would removing one to a boat at dock put the mast in danger of moving/falling?

Could someone point me to a good DIY book that covers this repair?

[roverhi]

Nigel Calder's 'Boatowner's Mechanical and Electrical Manual' is probably the best covering everything about a boat. Rather spendy but you might find a used copy on Amazon.

The mast won't fall down if you remove one stay/shroud at a time. If it will make you feel better use a halyard to temporarily replace the wire.

I'm not sure what you mean by cabin top/deck in area of chainplates being weak?? Is it soft and spongy when you stand on it?? If so, the long time intrusion of water has probably rotted the core material. Fixable but not easy. Best thing would be to pull all the chainplates, clean out as much of the rotted core material as possible, let it dry out for a couple of weeks then fill the void between the inner and outer deck laminate with thickend epoxy to a distance of at least a 1/2" or more around the slots. That will seal the core from getting more water intrusion and bring back the rigidity of the deck around the chainplate area. A more extensive fix might be needed later but at least it will stop the problem from spreading further and get you back on the water. BTW, talking about the filling the space between the inner and outer layer of the deck laminate formerly filled by the core material not the space between the cosmetic head liner and the deck.

Sillycone has two problems, it contaminates everything it touches so paint or anything else won't stick to it unless mechanically removed by sanding/grinding. It is also a crappy sealant. In shear, the bond between what it's trying to seal and the sillycone breaks down. Spent the first year of ownership on my first boat R&Ring every piece of hardware to stop the leaks caused by the sillycone sealant not sealing.

[bluewhaleCA]

> Spent the first year of ownership on my first boat R&Ring every piece of
> hardware to stop the leaks caused by the sillycone sealant not sealing.

Long year that. I've tried to look up what my boat is made of but it seems that depends on which sub batch of dozens it belongs to. Know it's not wood. Would glass support a 270 lb guy walking all about it carrying tools etc?

I hope to go down to the boat early tomorrow and take a closer look at the chainplates and a couple of other things. Then try to ask as few questions as possible to get to the bottom of it. .... then figure out what this 'bilge' thing is.

[Target9000]

Originally Posted by roverhi

LifeCaulk and 3M 101 sealant are polysulfides. 5200, 4200, Sikkens and other sealants are polyurethane. Butyl is butyl rubber typically used in automobile window sealant and usually available as strips of caulk though it does come in tubes.

As a side note, butyl rubber does come in many forms but not all work equally well. If you use it, go to an RV supply store and find the grey kind in a roll. Avoid the black and white and anything in the tubes. This stuff is like 10 bucks for a roll that should last damn near forever. Almost looks like a roll of double sided tape. If you can't find any locally check with Mainesail.

I'd avoid 5200 since you're almost guaranteed to have to repair this again. You'll want to dig the old caulk out before recaulking and 5200 won't be conducive to this.

All that being said, I would personally go with 4200 UV as noted by Minaret. You don't need strong adhesion here but flex and give are paramount. And you'll have to redo it sometime in the future.

[Target9000]

Originally Posted by bluewhaleCA

> Spent the first year of ownership on my first boat R&Ring every piece of
> hardware to stop the leaks caused by the sillycone sealant not sealing.

Long year that. I've tried to look up what my boat is made of but it seems that depends on which sub batch of dozens it belongs to. Know it's not wood. Would glass support a 270 lb guy walking all about it carrying tools etc?

I hope to go down to the boat early tomorrow and take a closer look at the chainplates and a couple of other things. Then try to ask as few questions as possible to get to the bottom of it. .... then figure out what this 'bilge' thing is.

Fiberglass will definitely support that kind of weight. It will probably be cored. That means it will be glass-core-glass. The core would probably be balsa or plywood in a 1974 vintage.

[daddle]

Originally Posted by markpierce

I'm sorry you purchased a boat with such poor design. Stay fastenings belong outside the hull and not through a deck.

Hilarious. Like the Mayflower? Chainplates thru the deck to a bulkhead or stringers is a fine way to build a boat. I agree the chainplates need to be pulled out, cleaned, carefully inspected, possibly replaced. Sealing at the deck is problematic. Some rigs will cover that joint with a tight fitting slotted stainless or HDPE plate. Keeps the sunlight off the sealant, provides more area for the sealant, and provides some support for the joint.

The OP needs to make sure those chainplates absolutely never leak.