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  Topic Review (Newest First)
02-02-2011 10:32 AM
FullandBy David,

I ended up leaving well enough alone. I did remove the fibreglass from all of them, except the one in the head and inspected them all. I also cut one out and removed it. They all looked absolutely fine.

I had a very knowledgable and seasoned ocean racing rigger come have a look and he thought they looked like they were in very good condition. He explained that the stainless steel and corrosion is more prevalent in the tropics. He also said that the biggest weakness on a chainplate usually occurs where the chainplate enters the hull. This is where you are most likely to get the standing pool of water that could eventually cause corrosion.

The one chainplate I cut out (which took forever) looked really good. There was no sign of fissure cracks or corrosion. The rust color on the plates came from non-stainless steel screws that held the chainplate box cover in place. There was a little rot on one of the knees. We built up the one knee again and re-glassed them all back in the way they were. I made one small modification though. We left a sliver of the chainplate exposed right at the top so that I could feel for moisture or see signs of leakage. So far, a couple of gnarly sailing trips later with some good winds and all is still fine.

I have some pictures that I'll get around to posting.

P.S. David - your website appears to be terminated. I hope you had a backup copy of everything as they appear to have lost all data in the termination.
01-01-2011 01:18 PM
Domenic I agree with Calebd...chain plates should be open. The fiberglass work on the knees looks like the resin was too hot. I would cut out the whole mess, and build new knees. Where the chain plates go through the deck, more often than not, leak.
01-01-2011 11:39 AM
What did you do about your chain plates?

Full and By,

What did you finally do about your chain plates?
Any more photos?

I also have a Cooper 416 and her chain plates are covered up by some nice carpentry, so I am loathe to break in to look. Thanks for the photo, now I at least know what's in there and that it will be a major deal to replace chain plates.

BTW, I have a little website for Coopers, you will find it at:

David Bereznai
SV Ansa
sail dot ansa at gmail dot com
04-22-2009 06:19 PM
FullandBy I was wondering that as well. I suspect my chainplates are simply glassed in with no bolts whatsoever. I would prefer bolts over glass any day.

Which has me considering replacing and redoing the current configuration to something more manageable in the future. To really get a good inspection I have to cut away the glass anyways, at which point I'm thinking perhaps I leave them uncovered and figure out some way to bolt them to the knees.
04-22-2009 10:21 AM
Northeaster my chainplates are not glassed over, just throughbolted to heavy fiberglass knees, that are part of the hull.

I am not used to looking at the Original poster's setup. Can someone explain the parts in more depth. For example, is it a one piece chainplate that goes through the deck and then extends vertically for a foot or so, down the side of the hull? Is it bolted to the knee at this point? And then there is the smaller horizontal rectangular shape at the bottom - Is that part of the upper verical chainplate, or bolted to it, etc???
04-22-2009 08:05 AM
kaluvic Good pics Brian...thanks
04-22-2009 05:28 AM
amarinesurveyor CaledD is right that stainless steel does corrode when deprived of oxygen.
I would recommend that you open up each one for inspection, it is something that should be done as a maintenance item as boats get older than 10 or 15 years old. This is something that you do not want to wait until it breaks before you fix it.
Here's a link to a couple of pictures I took, one is a failed chain plate, and the other is a cracked chainplate.
04-22-2009 03:25 AM
Originally Posted by CalebD View Post
One idea might be to bolt the chain plates through the knee wall but leave the chain plates uncovered. You might have to re-build the knee walls to do this in order to re-use the existing exit points in the deck.
The reason for doing it this way is that even stainless steel will (eventually) rust when deprived of oxygen where moisture is present.
I agree with CaledD 100%
04-22-2009 12:37 AM
Originally Posted by sailingfool View Post
If you are not comfortable after the above inspection, get a good surveyor to put a visit to your boat on his itinery. For the cost of an hour of his time, you'll get a better idea of what you have. My bet is that it's just fine.
This seems a good plan.. especially now that you have everything open and exposed. I agree that you may end up wishing that you'd left well enough alone if indeed everything is in fact OK.

I would think there are still some people around who may recall the exact details of construction - maybe try Queenship Yachts ( a luxury yacht company that originally grew out of the old Cooper business near Vancouver) for a potential contact. Or perhaps other Cooper owners?
04-21-2009 11:57 PM
sailingfool That discoloration is hard to call...could this be just some moisture collecting under the carpet? Have you taken off the deck trim plates and dug out whatever is under them? Rust if any would start there...if the fittings look good under those plates, I'd recaulk and go sailing.

I also don't care for the glassed in fittings..why does a builder do that...but you are going way out in left field and looking for trouble to start changing the original construction without establishing that it isn't still servicable today.

If you are not comfortable after the above inspection, get a good surveyor to put a visit to your boat on his itinery. For the cost of an hour of his time, you'll get a better idea of what you have. My bet is that it's just fine.
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