Chainplate leaks

[romanystar]

I'm frustrated. My old glass Ohlson 38 has had chainplates leaks every couple years since I've owned her, 25 years.

The chainplates were replaced with high polish stainless ten years ago. The originals were looking pretty rough. Both sets have leaked.

I've cleared a space in the deck that allows about a quarter inch of caulk space between the stainless and the deck. There are Starboard caps that fit tight around the chainplate, and overlap the holes in the deck by about an inch.

When I re-caulk I dig out all the old stuff, and use a wire brush on the drill to get the last bits. I go after the stainless with a red 3M pad, which has taken a bit of the polish off.

I've tried 5200, 4200, a couple Sika products (one with a "special" primer that smelled like denatured alcohol) and the latest was Teak Decking Systems deck caulk.

They all let go around the stainless!

Any suggestions?

[CSY Man]

I used flexible epoxy.
Worked good.

[Pete7]

Why are the chain plates highly polished? surely you want the goo to stick to them?

Leaking after a couple of years isn't good, is anything moving by chance, rigging alined, too slack or or too tight perhaps?

Pete

[CR38]

I've heard that if you don't keep the shrouds tight enough then the chainplates will shift and this breaks the seal and leaks occur.

[sparrowhawk1]

Use butyl rubber. It's also a good idea to build a raised section around the chain plate.

[Scottuk]

Why are the chain plates highly polished? surely you want the goo to stick to them?

Chainplates are polished to takes out scratches were water likely will sit and stay.

[transmitterdan]

Use Butyl rubber as the sealant. The starboard caps might benefit from having the opening around the chain plate at least 1/8 inch and fill this space with butyl rubber as well.

Caulking compounds like 4200 and Sika will all leak after a while. They do not remain "gooey" enough to stay with the chain plate as it flexes. Here is the good stuff:

http://www.pbase.com/mainecruising/butyl_tape

The stuff at the local hardware store isn't the same.

[Stu Jackson]

Butyl tape, like this, sounds like we have similar chainplate designs:

C34 mark 2 chain plates leaking - Chainplate flix

[Celestialsailor]

If 5200 didn't work, it might be just condensation. I had this happen when I lived in a cooler, moist environment. If you spray the chainplates down on a warm day, do you still get the water?

[transmitterdan]

5200 will always leak after a couple years. And it's a nightmare to remove. Sika or 4200 will also leak. Chain plates through the deck cannot be reliably sealed with non-gooey sealant.

Polyurethane sealants can work where they are under pressure but not in chain plates through the deck where the pressure can go negative. Butyl rubber will handle this case.

[sparrowhawk1]

Originally Posted by transmitterdan

Use Butyl rubber as the sealant. The starboard caps might benefit from having the opening around the chain plate at least 1/8 inch and fill this space with butyl rubber as well.

Caulking compounds like 4200 and Sika will all leak after a while. They do not remain "gooey" enough to stay with the chain plate as it flexes. Here is the good stuff:

http://www.pbase.com/mainecruising/butyl_tape

The stuff at the local hardware store isn't the same.

I have always used the butyl tape. Either purchased from an automotive store 4 windshields or from a marine supply. can you tell me why the stuff sold in hardware stores is not the same. my friend bought a caulking gun tube of it which I never heard before, seems like a cool idea and much cheaper, but I guess you get what you pay for.

[Terra Nova]

Your chainplate seals are improperly designed--that's why they've been leaking for 25 years. Starboard caps? HA! What sticks to Starboard?

Chainplates are constantly working, worrying away at the sealing material. If the sealed joint is not raised above deck level, you can expect standing water to work its way down the chainplate.

On Terra Nova, I epoxied wood bosses to the deck around the chainplate exits, and welded rectangular stainless caps to the stainless chainplates, about 3/4" above the deck. The caps provide a huge surface area to caulk, and protect the caulking from weathering. Water is shed off the caps and cannot run down the chainplate.

[Cheechako]

I've had good performance out of 5200. I threw away the cover plates though. I make a nice big fillet from the deck up the plate with the 5200. It adheres well and water runs away. Those cover plates seem to just allow water to get under and stagnant if you ask me. However, 1/4" clearance is a lot around the plate. I'd rather see 1/8".

[Stu Jackson]

Originally Posted by sparrowhawk1

I have always used the butyl tape. Either purchased from an automotive store 4 windshields or from a marine supply. can you tell me why the stuff sold in hardware stores is not the same. my friend bought a caulking gun tube of it which I never heard before, seems like a cool idea and much cheaper, but I guess you get what you pay for.

Pretty much. In the link to the pbase website, Maine Sail explains that he did his homework and research. Why not read the link to answert this question?

[neilpride]

I suspect the gap between the plate and the chainplate slot in the deck is few mm, this allow for a lot of flexing and sooner or later caulking failing, its a good idea to clean the old caulking really well , use tape to close the underneath side of the slot, clean really well the side of the plate deck level, if you can pull out the plate better, pour a litle mix of West mixed with silica inside of the slot, just to fill the gap , not much or you got problems later with the slot cover plate, and i use buttyl tape to cover the small tiny gap and slot cover plate left after the epoxy as cured. cheers...