Chain plate covers
- Thread starter higgs
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higgs, Good Old Boat had a good article a few years ago. A skipper, maybe IIRC with a C36? just built up the fiberglass deck around his chainplates.
Good sealant or butyl will do it.
I have the butyl and will be doing mine soon.
Good sealant or butyl will do it.
I have the butyl and will be doing mine soon.
The orriginal chain plates on the Hunter 33 are 5/16 " thick with washers welded on both sides to bring the pin hole thickness to 3/8. The cover plates have 5/16" openings which means they can not be removed unless the plates are pulled. Mostly just a pain in the butt.
I had 3/8" thick plates made up by Garhauer. The plan is to pull the old plates, open up the holes in the deck getting rid of any soft core, ( there shouldn't be much core because the pass through openings are very close to the edge of the deck where the inner and outer skins come back together). Mold raised islands around the openings similar to what was done in the "Good Old Boat" article, except in epoxy rather than wood. I will open up the slot in the trim plates using the top notch, high quality, China made X - Y table and equaly precision also China made machine vise I bought from Enco on line for about $100. Guaranteed accurate to 1/4". Or so. Assembly will be with some grey butyl I got on line from a small company only a few people have heard of.
My feeling is that the trim plates can help to push the butyl into the opening the chain plates come through. They also can make it look a bit better, although as some people can attaes, cosmetics are not my first priority.
I will be taking pictures at times when my hands are not covered in epoxy and fully ecpect to post them here within the next 10 years or so. Ah, better idea; maybe I can wheedle H33CRich into doing the post. He's ssooo much better at that than I am!
I'm guessing this is the issue Higgs is looking at.
I had 3/8" thick plates made up by Garhauer. The plan is to pull the old plates, open up the holes in the deck getting rid of any soft core, ( there shouldn't be much core because the pass through openings are very close to the edge of the deck where the inner and outer skins come back together). Mold raised islands around the openings similar to what was done in the "Good Old Boat" article, except in epoxy rather than wood. I will open up the slot in the trim plates using the top notch, high quality, China made X - Y table and equaly precision also China made machine vise I bought from Enco on line for about $100. Guaranteed accurate to 1/4". Or so. Assembly will be with some grey butyl I got on line from a small company only a few people have heard of.
My feeling is that the trim plates can help to push the butyl into the opening the chain plates come through. They also can make it look a bit better, although as some people can attaes, cosmetics are not my first priority.
I will be taking pictures at times when my hands are not covered in epoxy and fully ecpect to post them here within the next 10 years or so. Ah, better idea; maybe I can wheedle H33CRich into doing the post. He's ssooo much better at that than I am!
I'm guessing this is the issue Higgs is looking at.
Chainplate covers exist to aid in maintaining a seal between the adhesive the the chainplate. Just like any other item you are bedding with adhesive, you should install the chainplate over wet adhesive, tighten mostly all the way, and then go back and tighten that last little bit the next day after the adhesive cures. This places a compressive load on the adhesive which should help to seal the chainplate even when the adhesive is no longer bonded to the chainplate.
So if one can obtain a leak proof seal w/o the covers, then the covers are not needed?
If you have them I would certainly use them. First the hole through the deck should be larger than the chainplate - to allow both for movement and a place for the sealant. The cover both compresses the sealant and protects it from uv and general wear and tear. Some build islands around the chainplates so water can't pool around them, as I have installed. Chainplates are probably the most common leak risk on a sailboat as they move, while a properly installed cleat can't move for example.
Here is a pic showing chainplate covers - not my boat. The hole through the deck under the cover will be larger than the hole in the cover.
Here is a pic showing chainplate covers - not my boat. The hole through the deck under the cover will be larger than the hole in the cover.
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For the first three/four years after I bought my boat, even after digging out the old caulk and renewing with recommended caulk for the purpose, I still had leaking into my cabin through the chain plates when raining.
It seemed that after time, and with the fluxing of the chain plates under sail, the caulk would lose adhesion with the vertical chain plate allowing water to find its way in. Removing the chain plate cover on the deck and digging around revealed that the caulk to deck seal remained good.
What has been working now for me (illustrated in the attached photo) is first I first used very fine wet/dry sand paper to dull/scratch the chain plate just above deck level and then wiped with acetone; then filled the under cover plate void with caulk (after first digging out the old caulk best I could); then dropped the cover down and screwed in; then before the caulk set up, continued to add caulk all around the chain plate gradually tapering the thickness as I went up; and finally after the caulk was fully cured, wrapped the caulk to chain plate interface tightly with UV resistance electrical tape. The pressure of the tape against the seal so far is preventing the caulk from detaching from the SS chain plate. And the adhesive on the electrical tape itself also seals. I put a thin bead of super glue on the wrapped ends of the electrical tape so it won't gradually "unwind".
I had noticed in the gutters of my house that the gutter caulk used by the roofing company a decade ago was still going strong. So I bought a tube of the stuff for the boat instead much more expensive marine caulk.
So far so good. No water ingress this past winter.
It seemed that after time, and with the fluxing of the chain plates under sail, the caulk would lose adhesion with the vertical chain plate allowing water to find its way in. Removing the chain plate cover on the deck and digging around revealed that the caulk to deck seal remained good.
What has been working now for me (illustrated in the attached photo) is first I first used very fine wet/dry sand paper to dull/scratch the chain plate just above deck level and then wiped with acetone; then filled the under cover plate void with caulk (after first digging out the old caulk best I could); then dropped the cover down and screwed in; then before the caulk set up, continued to add caulk all around the chain plate gradually tapering the thickness as I went up; and finally after the caulk was fully cured, wrapped the caulk to chain plate interface tightly with UV resistance electrical tape. The pressure of the tape against the seal so far is preventing the caulk from detaching from the SS chain plate. And the adhesive on the electrical tape itself also seals. I put a thin bead of super glue on the wrapped ends of the electrical tape so it won't gradually "unwind".
I had noticed in the gutters of my house that the gutter caulk used by the roofing company a decade ago was still going strong. So I bought a tube of the stuff for the boat instead much more expensive marine caulk.
So far so good. No water ingress this past winter.
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Sometimes the problem isn't adhesion but the ability of the sealant to stretch. If the sealant is capable of stretching 100% and you start with 1/16" it can only stretch to 1/8" before the seal is lost. If you start with 3/16" it can stretch to 3/8" before the seal is broken.
Maybe so -- but it's got to also have something to do with how well the caulking sticks to the surface. Yes, if the two surfaces have little/no flex, then makes sense that the sealant doesn't have to adhere all that well to still maintain the seal integrity. And also if the surfaces will allow a good chemical/physical bond. My experience is that stainless steel is a surface that challenges caulks to stick well over a period of time. It's better than adhering to teflon plastics (I know teflon is the worst case example), but still a challenge for the flexing chain plate surface. Hence my success using the constriction properties of electrical tape wrap to help prevent the caulk seal from separating from the chain plate surface. And the seal of the electrical tape itself.
My problem is that the covers won't come off w/o removing the entire chain plate. Covers will only lift up about an eighth of an inch, so it is impossible to clean out the old sealant unless I remove the entire chain plate. Lousy design. In order to remove the entire chain plate I have to cut away a section of the rub rail, which was affixxed over the chain plate bolts which are attached to the side of the hull. There is a way out of this. I just have to find it.
Fast fix " liquid tape "..in electrical department, I don't know how long it will last But; I've allready got two years!....Dale P.S. Comes in colors!
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