Chain Plate Life Span

[stevensuf]

ok some pics attached the one with less rust is the starboard side the other pic with more rust is the port side and it has a slight bend in it,mmm any thoughts.

[stevensuf]

nb the remainder of the standing rigging was renewed last september and i asked the riggers to inspect the chain plates and they said they were ok, but i dont like the small bend on the port one and the rust coming from it!

[Cheechako]

A minor bend will not effect it. In fact, in theory the work hardening makes it stronger than the other one! It could be a fastener causing the rust. That type of chainplate has very little area embedded to stay wet and corrode.... so that's a good thing. Pretty minimal fasteners for a boat that size though. I would be more worried about the condition of the fasteners on both sides than the plates themselves. Looks like they might be easy to get off and replace the fasteners....?
I cant tell... but if the bend is right at the top fastener hole, then it's worth inspecting for a crack though. (stress risers at the hole can cause cracks/ propagation of cracks)

[Target9000]

Originally Posted by stevensuf

nb the remainder of the standing rigging was renewed last september and i asked the riggers to inspect the chain plates and they said they were ok, but i dont like the small bend on the port one and the rust coming from it!

If something bothers you on your boat don't listen to what other people say. YOU know its a problem. Fix it. YOU are responsible for your boat, its safety, and the safety of those on board. Even if the chain plate really is okay, the piece of mind is worth changing it. And it isn't like its a worthless expense, you'd have to change them eventually anyway. The closer together the rigging is all changed the easier it will be to refurb in mass on the next refit anyway. I'd change it.

[stevensuf]

ive had a look at the bolts on the other side of the hull, they look fine, might take the plate off and have a good look, the rust looks like it is coming out from the bolt at the part, had a quick rub down with wet n dry and the surface underneath looks fine! the plates are about 1cm thick 5cm wide about 25cm long.

[Target9000]

Also as a side note, I'd pull that tape off. Let the water drain out of those turnbuckles properly and give yourself visual access to those split rings.

[delmarrey]

Originally Posted by stevensuf

ok some pics attached the one with less rust is the starboard side the other pic with more rust is the port side and it has a slight bend in it,mmm any thoughts.

Just out of curiosity, how thick is the fiberglass at the fasteners? And are there some good sized backing plates on the inside?

A bend in a chain plate is fine as long as it is in direct line with the stay. If it is flexing back and forth, it's doomed!

To help prevent that rust use a marine sealer between the plate and FG to seal out any water. And keep them clean of rust as regular maintenance using an acid based cleaner/polish. Rust will grow just like mold/moss.

[Cheechako]

A bolt with too much iron content could lok good on both ends and be nearly corroded away inside in the damp closed up area.... Might be worth pulling that one suspect bolt anyway.

Just out of curiosity, how thick is the fiberglass at the fasteners? And are there some good sized backing plates on the inside?
Yeah, that's the first thing came to my mind also....

[Jolly Roger]

There is no rule of thumb and I agree with Target9000. All the criteria is important, material, thickness, age, fasteners, thickness of hull, type of fitting, (inboard or outboard), etc, but if you are worried about these very important items, renew them.
I’ve just removed all twelve on my 1977 Down East 45, in preparation with re-rigging. This is an American vessel and built like a tank.
All the plates are stainless, ½” thick x 2” wide x 16” and 20” long. The 16” plates have five ½” stainless bolts and the longer ones have six. I have cleaned and polished all the chainplates and bolts, then inspected them with a magnifying glass. Four will be slightly re-shaped to fit their new location. I discarded about ten bolts which were damaged when we removed them, but otherwise I’m re-using them with new lock nuts and washers.
I’m happy with this and when the plates are re-bedded and sealed they will be better than before.

[Red Horse]

I would replace that turnbuckle pin. Pull the fasteners and inspect them. The chain plates should be aligned with with the load. I don't know why manufacturers build boats with chain plates and rigging misaligned.
Just a few months ago we built a new chain plate for a 60 footer that lost its rig due to crevice corrosion. Boat was 20 years old if I remember correctly. When replacing chain plates and fasteners its best if you can find material from a US mill. Or as mentioned earlier go with titanium.

Sarge

[stevensuf]

The rigging from the plates upwards is all new, i will pull a couple of the bolts one at a time and inspect, the backing is just large washers, typical production boat, but the load is longitudinal, the glass is a good inch and bit thick , the bend is in the direction of the mast, the other plate has a slight bend toward the mast but not as pronounced as they more rusty one. There are no wigns of rust on the backing washers/bolts inside the boat.

[Bridger]

I have a 33 year old Cheoy Lee 38' offshore and the chain plates are original. I pulled the backstay plates to check them and yes they are rusted. There were no cracks but I'm replacing them anyway. Is 316 stainless the best material to use? Crusier2B did you cut and drill your 316 yourself ? If so how did you do that?
Thanks

[Paperbird]

When we bought our 1984 Pearson, I pulled the plates to look at the underneath side. I'm with Target, my boat, my problem. Two of the chain plates were cracked and ready to fail. Replaced all of them. Had Carter fab build all new. Excellent workmanship. Highly recommended.

[delmarrey]

Originally Posted by Bridger

I have a 33 year old Cheoy Lee 38' offshore and the chain plates are original. I pulled the backstay plates to check them and yes they are rusted. There were no cracks but I'm replacing them anyway. Is 316 stainless the best material to use? Crusier2B did you cut and drill your 316 yourself ? If so how did you do that?
Thanks

If you've never drilled SS or have any idea of how to, I'd recommend you have them done at a machine shop. SS work hardens if not dome properly and you may just end up with scrap metal.

316 or 304 material is fine but should be polished to prevent corrosion.

[sabray]

Drilling is really quite easy. Lots of water pouring on the surface couple of regular old drill bits and a bench grinder to sharpen them. Did mine in 316 went up one size. The polishing was the real work. Send them out for polishing it's way to much work. But can be done if you have the time and not the money.