CAS or "Chainplate avoidance syndrome"

[michaeld]

We were racing and hit by a Beneteau Cyclades 50. The backstay took the brunt of the collision, and it exposed previously undetected corrosion of the chainplate. Imagine was built in 1985, and I am confident that all the chainplates were original. That event prompted our decision to replace all seven chainplates and shrouds. My wife and I completed the project for 40% of quotes. We now sail offshore with confidence. Questions?

[Jim Cate]

But I daresay that no unplated bronze is ok in direct contact with 316L stainless in the marine environment, which is one of the worst for galvanic corrosion.

In every one of the chrome plated bronze turnbuckle bodies that I've had the plating was on the external surfaces only, and the tapped holes where t he s/s and bronze actually touched were NOT plated. Similarly the holes where the s/s clevis pins go are bare bronze.

FWIW

Jim

[lifeofreilly57]

I've pulled the chainplates on every boat I've owned, I've seen too many mast failure on boats who's chainplates looked "fine". Depending on the value of the boat it could be totalled by the cost of a new rig, that's if the overboard rig doesn't bash holes in your hull and sink it in the first place.
In my experience, you can't tell from the visible parts of the chainplates whether their pocket corroded or about to fail from the deck. Some looked great from the deck and were pretty much junk in the hull, were you couldn't see them. It's also a good opportunity to have them dye tested, you never know where there'll be micro stress cracks.
Yes, it's a a pain in the neck, but also a good opportunity to seal the deck core where the chainplates pass through, which I've done as well, a bit of routing, some thickened epoxy and your deck core is sealed from the elements, which is cheap insurance.
If you plan on owning your boat for more than a year, or even considering an offshore passage I consider it a must do.
Why would you have the standing rigging inspected in a survey, then hope that the chainplates will be fine without inspecting them?
On our current boat, they were glassed in at the deck and covered with woodwork in the interior cupboards, it took a day to pull them out and another day to re-install, a small price to pay for peace of mind, oh, and I sealed the the deck core while I was at it. That was about four hours work and a day or two to cure.

[Dockhead]

Moody 54 chainplates. Far more massive than the ones on the Discovery 67 I sailed across the Atlantic this year. That's two pieces of 10mm HT steel (not stainless) plate, not encapsulated, secured by 12x 12mm bolts, 40mm diameter clevis pin. Each side. In my opinion, chainplates are worthwhile overbuilding like this.

[PUDDLE JUMPER II]

Originally Posted by lifeofreilly57

Yes, it's a a pain in the neck, but also a good opportunity to seal the deck core where the chainplates pass through, which I've done as well, a bit of routing, some thickened epoxy and your deck core is sealed from the elements, which is cheap insurance.

If you plan on owning your boat for more than a year, or even considering an offshore passage I consider it a must do.

So intriguing idea of putting a coat of epoxy on / inside the cavity that the chain plate passes through... Did you use GFLEX? Or some penetrating epoxy?

I am in the middle of a chain plate HELL at the moment -- digging out 4 feet of chain plate from the hull of EACH of the 10qty stainless steel chain plate KNEES + Chain plates embedded/burried in fiberglass -- sandwiched into the hull. German Frers and his design team thought this was a great idea in the 70's...

Back to your comment--- when I complete my epoxying the thru-deck openings for the chain plates--- is their some standard clearance that the chain plate should have from touching the deck? Or just dead center of the opening and calk it in from there!? This is the first major open heart surgery I am conducting on the boat-- and I am looking for good practices to follow here-- hence my comments and queries...