Chainplate Cavalier 32

[brucesagnol]

Hi - I am new to this forum and am hoping someone can help me with some information. I own a Cavalier 32 and had a chainplate fail while sailing. Inspection of the piece which has come out through the deck looks like it has been subject to both stress and corrosion. It appears that the chain plate rests against the inside of the hull and is glassed over. It has a knee where it exits the deck. I would be very grateful if any one could supply me with any information about removal and replacement of chain plates on this or similar type of yacht

Thank you

[Snowpetrel]

Its a pretty common problem on older boats. Stainless is very subject to stress corrosion cracking and crevice corrosion. Your other chainplate is probably also suspect, and maybe even backstay and forestay fittings. Basically any embeded stainless, even stainless bolts are suseptible to this failure mode.

It may be possible to fit new chainplates just inside the existing ones. Or otherwise carefully cut out the old ones and renew. Another approach would be internal chainplates that tie to through bolted deck mounted chainplates.

At least those cav 32's have a decent reputation for being built tough.

[Snowpetrel]

The cav 32 has chainplates reasonably close to the deck edge. A quick and strong fix is external chainplates. This is what I did on my old 26 foot boat, drilling through the suspect internal chainplates. In you case is would look much less sleek, and effect the genoa sheeting angles. reducing pointing ability in flat water.

You have fore and aft lowers, so six suspect chainplates to replace. Its a biggish job, but once a system is sorted out it should go quickly. Some photo's of the internal structure and chainplates on deck would probably help sugest a few practical solutions.

At least you didn't loose the mast.

[GordMay]

Greetings and welcome aboard the CF, Bruce.

[Sony126]

Hi, just wondering how you are getting on with your chainplate replacements?
We are preparing our Cav32 to go offshore and are just in the process of having a marine engineer draw up alternative chainplate designs for our fwd/cap/lower shrouds. It's looking likely that we are going to go for an external chainplate, possibly circular design.
We have been feeling like we are just being somewhat super paranoid at the thought of grinding the glassed-in old chainplates off just so that we can inspect them as we haven't had any fail on us.... Yet! So, sorry to say this, but we are actually glad to have found your post and to hear that another Cav32 has had a chainplate fail.... We feel less paranoid now!
Did it do much damage? Which chainplate failed?
A previous owner had definitely changed the design of our fwd lower chainplate (which doesn't seem to be an improvement and also seems to have let in water below deck).
Anyhow we could talk about chainplates forever, so we will keep it brief (mildly obsessed with the subject atm).
Let us know where you are up to and we will be happy to share ideas! Cheers

[brucesagnol]

Hi
I have inspected the other chain plates and have found various degrees of corrosion in the 4 other of others as well. The starboard cap shroud chain plate had been replaced previously and has no corrosion however I am not happy with how it was done as it appears the new one was glassed over the top of the old one. I will be replacing them all (including back stay) with the same design as I also am looking to go well offshore in the future. The one that failed was the port side forward lower. It was under a lot of tension at the time as we were going to windward in 17 to 20 with the back stay hard on. No other damage done, the mast remained well supported. We didn't push our luck and dropped sail once we figured out what had made the loud bang and shudder. (The shroud did not come clear of the deck - just lost all its tension.)

If you send me your email address I would be happy to email you photos I have taken with cabinetry removed so you can get an idea of where to look.


Cheers

[Alan Mighty]

Stress crack corrosion and crevice corrosion are par for the course with 316 stainless steel. 316 can be thought of as a compromise (or a compromised material): it has a relatively short service life.

I've a different design and I removed and changed chainplates a few years back.

I avoided 316 and went instead for duplex stainless steel, specifically 2205 and 2504. Much stronger and with much longer service life than 316. Longer as in 2.5x longer.

You're a few days sail north of me, but for what it is worth following this link will lead you to mention of the people I used for 2205 plate and for fabrication: http://www.cruisersforum.com/forums/...ml#post2350834

With luck, you'll find someone who can supply and cut the plate and someone to do the fabrication closer to you.

[Sony126]

Hi again,
sorry for the delay getting back to you.... we have started remodelling our forward cabin and it's taking up all our spare time atm.
I don't think I mentioned that we had all our rigging overhauled and upgraded in Feb this year at which time we removed both our fore and backstay chainplates. Our backstay chainplate had a some pitting but my husband noticed a decent stress fracture that we actually opened up and it broke in half, just bending it by hand! We felt very lucky this hadn't happened on the water. It is a different configuration to the others though as it consists of 2 separate SS pieced bolted together through the deck. The lower section is like an upside down U that fits over a knee? (think that is what it is called).
I will see if I can post some photos.
Our drawings came back from the engineers and they have designed external chainplates made from 12mm SS flat bar that is mounted onto thick plates of fibreglass (also on the outside of the hull). By doing it this way they have designed it so that we don't need to have backing plates - just large washers (hopefully eliminating the need to remove the old ones so that we can just cut them off below and seal up the deck totally above). Still waiting to see the bill for the design.... but we are happy!
email is sony_126@hotmail.com

Thanks again for sharing!

[Sony126]

Here are a couple of photos from Feb when we had de-masted. The first one is our old backstay chainplate with the fracture just visible.
the other 2 (sorry I forgot to rotate them first) are of the starboard fwd lower shroud. I think I mentioned before that we are sure the fwd lowers had been replaced before as they are a different design to the others. Just a really long flat bar of SS bolted through the bulkhead and at a totally different angle to the stay. Although the stainless was in good condition they both definitely leak water down into the cabin and along the bulkhead so we were keen to redesign and remove asap.
Hope this all makes sense....

[Snowpetrel]

Wow, lucky the backstay held together as long as it did!

[Petronnella]

[QUOTE=brucesagnol;2635497]Hi - I am new to this forum and am hoping someone can help me with some information. I own a Cavalier 32 and had a chainplate fail while sailing. Inspection of the piece which has come out through the deck looks like it has been subject to both stress and corrosion. It appears that the chain plate rests against the inside of the hull and is glassed over. It has a knee where it exits the deck. I would be very grateful if any one could supply me with any information about removal and replacement of chain plates on this or similar type of yacht

Thank you

I have a Cav 32 and I'm looking for the same information. Did you remove yours? If so, did you find out how they were installed?

[nuku34]

I own a NZ Cav 32, Betelgeuse II. As far as I can tell, all the NZ Salthouse built Cav 32’s had ss flatbar chainplates on the cap and after lower stays. The flat bar went through the deck and down the inside of the hull. It had 2 or 3 short pieces of flat bar welded across it, and a triangular “knee” welded to it with one side of the triangle up against the inside of the deck. Where the flat bar touched the hull and deck it was heavily glassed over. On the deck, there is a small raised area where the chainplate comes thru and an ss plate with slot screwed to that area to act as a seal.
Forward lowers have a “T” section tang on the deck connected to a big backing plate under the deck by 4 bolts.
Where the flatbar tangs come through the cored deck is of course the place where crevice corrosion can happen if salt water gets in there. Its the only fault I have with the boat’s construction. The tangs should have been designed to be bolted on from the inside and removable so they could be pulled and inspected and easily replaced.
To take them out now and replace the whole assembly with the knee, etc would be a big messy job! One “fix” I’ve seen on one Cav 32 is external chainplates. They are ugly and put the caps further outboard, messing up the genoa sheeting angle.

[AlexSiun]

Good day

I’m planning to buy Cav32 (1974) and chainplates require serious attention, I would be grateful to see how modified versions look like, should redesign those areas or just cut it out, replace corroded flat bars and glass it over back again. That is a big head scratch.

[d_mac]

Hey, I've recently bought a Cavalier 32 as well. I love the boat it seems really solid! But I've been wondering about the chainplates as I'm certain they're original and do have some light rust staining visible.

I'm okay with grinding away the interior glass that encapsulates them, but then I was thinking of the following options to remediate:

• Using a higher stainless steel grade than 316
• Copying the size and shape of the existing plates and replacing with G5 titanium
• Getting some carbon composite plates made up and glued in

Has anyone experience with doing anything like this and what the likely costs are?