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Aloha to All
i am thinking about changing out my chain plates. Does anyone have the details for fabrication??? Are the typical. I have 1983 – cutter rigged hull #217. for those of you that have done the job, any reccommendations would be greatly appreciated
please respond,
James – Island Muse – Honolulu Hawaii
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Hi James-
Here’s a link to a relevent article
http://www.oceannavigator.com/ME2/dirmod.asp?sid=&nm=&type=Publishing&mod=Publications%3A%3AArticle&mid=8F3A7027421841978F18BE895F87F791&tier=4&id=803A297D175C4C85842B61DB799BB305
We just took the chainplates out and had them duplicated. All our shroud chainplates are the same dimensions. If you search my name on the ON site, there is also an article on stainless steel. Duplex stainless is available on line and is a better choice than 316 or other Austinetic alloys.
Quent
Clairebuoyant, #132 -
I’ve replaced only the transom chainplate in my sloop. I investigated replacing the other chainplates and have a couple of comments.
The rigging vendors want big bucks for a chainplate. Maybe someone on the list knows where they can be purchased reasonably but I haven’t found a source.
I bought my own stock and cut and drilled my transom chainplate. This was a bigger job than it might seem.
http://www.richardcarter.net/boat/TransomChainPlate/From that project, I learned that cutting and drilling your own isn’t a big deal. Stock is relatively inexpensive. You’ve got six chainplates. I’d estimate stainless stock at about $150 for the set. Cutting is simple if you invest in a cutoff saw (approx $100). You also need a drill-press and cobalt drill bits to cut the holes. If you center-punch the holes and then drill successively larger holes, say 1/4, 3/8, and 1/2, you should be able to drill out one plate in about an hour. If you are careful and use cutting oil, the drill bits should last for the job. Since you’re making six of these, it might be worth wile to make a jig for the pilot holes if they are all identical.
In retrospect, I should have sent the plate out to be electro-polished. For the stays, this may not be important since they are basically below deck.
Regards
Rich
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This group is a very prolific set of writers. I apparently need to step up my game and start submitting to magazines. 😉
Thanks for the link Quent, I’ve saved it into my archive!
-p
s/v Deep Playa | Pearson 424 #152 | http://www.DeepPlaya.com<.. snip>
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Owners no more...
Thanks Dawn and Patrick! -
I’m curious did you get the plates to a high polish before you installed them?
At the Brion Toss Rigging class he said that the most expensive part of making stainless chainplates was the polishing and that the polishing is what helps slow crevice and surface corrosion by eliminating or lessening the amount of surface area. But he made is sound very doable, its just takes time.
-p
s/v Deep Playa | Pearson 424 #152 | http://www.DeepPlaya.com<.. snip>
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Owners no more...
Thanks Dawn and Patrick! -
I replaced my chain plates last year.
I pulled all the plates, ordered the stainless bar stock and had a local machine shop drill and shape them. The good news is that all the holes were the same.
I did not polish the chain plates as the ones I pulled were not polished. I could see no major issues, but replaced them all.
Total cost was less than $400.
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Yes, I polished the chainplates. Polishing is straightforward. An hour should be more than enough to polish the set of six. You first clean them off with a flap-sander on a hand-held grinder. I suppose you could use a bench grinder too if you can get it to fit. You then use a starbrite pad mounted on the same grinder with Mother’s mag cleaner. There are typically a set of four starbrite pads in a polishing set. This will get them buffed to a pretty good shine in a few minutes, but the electro-polishing process removes surface contaminates rather than just rubbing them smooth. You’re only going to have a couple of inches of chainplate visible. At that, it will be hidden by deck caulk and chafe tape. I think hand polishing is just fine.
Rich
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John
$400 seems reasonable. If the stock runs under $200, that leaves $200 for labor. I would think a good machine shop should be able to cut and drill a set of six plates in a couple of hours. I called a couple of rigging shops and got quotes over $200 for one chainplate.My plan has been to keep water out of the deck and out of the chainplates. This means rebedding the chainplates every couple of years. I’m trying a new caulk that might last longer however. If you can keep the water out, I expect the chainplates to last indefinately. Did you consider just polishing and inspecting your existing plates before replacing them?
I recently had a screw head from one of the stanchion fasteners snap off. There was no obvious reason for this. I suspect crevice corrosion.
BTW: lose any bronze toggles that remain in your rigging. My rigger tells me that some insurance companies are refusing claims caused by failures of these. He’s replacing with stainless. All mine are gone.
Regards
Rich
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KATO here in Annapolis lightened my wallet by about $600 for seven chainplates made from 316 bar stock. If I were to do it now, I would order the metal on the Internet, using Duplex 2205 alloy, and get a local machine shop to shape and drill them.
The problem with 300 series including 316, is that it is suseptable to stress corrosion cracking. The crack progresses along the grain structure of the metal kind of like paper tearing. Duplex is a mixture of two different grain structures which gets in the way of the progression of the crack.
Polishing, especially electropolishing makes the chainplates prettier, and makes it easier to see cracks, but probably doesn’t do much to prevent them from failing.
One other thing to look at are the tangs that connect the lowers to the mast. Ours had spiderweb cracks and were close to failure. Polish them with Mother’s, then look for cracks in reflected light.
Quent -
Quent
I read the article and would like to know more about the fiberglass plates and how you sealed the deck. Do the screws going through the fiberglass push against the deck and hold the plates off the deck? What type of caulk did you use? I have been thinking of taking on this project and don’t want to have the same situation down the road from deck leaks.
Linus
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Hi Linus-
I find the fiberglass in Gemini Catamarans’ dumpster. Basically it is cutouts and rejected parts made of laminate about 1/4″ thick. The plates are about 50% bigger than the SS cover plates.
Yes, the screws stick out on the bottom, maybe 1/8″. This just makes space for caulk to form a gasket. Re type of caulk, the jury’s still out. 5200 sticks better, but silicon is more elastic. Bottom line is that you get more caulk around the chainplate, but it is still far from perfect. If Pearson had bothered to align the chainplate to the shroud angle, the chainplate would not move. They didn’t, so it does move. Things that move leak, and eventually they break.
Quent
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