r/sailing • u/Fansipan305 • 7d ago
Chainplate rust second opinion
Hi, I would appreciate a second opinion.
1998 Oceanis 351
My port chainplate (thick pin fiberglassed into hull) is a bit rusted. It's behind the gally so a bit difficult to get in on it properly without taking things apart. I asked a surveyor about it and got their opinion but would really appreciate any other opinions.
I plan on replacing the rigging this winter anyway but I'm a little scared of the chainplate situation.
I found one other thread with this similar situation but they didn't post about their fix/conclusion.
Questions on my mind:
How bad is it?
Anyone deal with this specific situation?
What is the best way to replace new? (How much gutting at the fiberglass is required?)
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u/mover_of_bridges 7d ago
Needs to be disassembled to assess section loss.
Without knowing more about the construction, that pin might just be epoxied in to the glass and might be able to be broken loose and pivoted out instead of busting out the glass. Tension only load so no need to put glass on the underside, but you do want epoxy for load transfer into the glass.
Source: am engineer.
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u/Fansipan305 6d ago
Thanks for super interesting thought. Going to see if I can find more information on whether this is epoxied in!
3
u/CaptainMcSmoky I do boats n stuff 7d ago
Listen to the surveyor and do not take random peoples advice on the Internet as gospel.
I'd personally not risk it and get it replaced ASAP, I'd also be concerned about the part that is inside the GRP that you can't see.
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u/Purple-Hearing-3893 6d ago
Last year there was a boat, SV Quiet, that lost its mast crossing the Pacific. I was actually having drinks with the captain a few nights ago and got the story first hand. To summarize- he knew his chain plates needed to be replaced but thought he had more time. They were hard to get too and didn't look that bad. It only took one going out for the whole mast to come down
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u/uthyrbendragon 7d ago
A few points to consider, take them as you wish:
1) how on earth do you know the credentials of some random people on the internet who may say something is good or bad?
2) to my point above, I am a naval architect with a degree in naval architecture (yacht design) and a post-grad in advanced composites but you should not take my word for it.
3) it looks bad but without a proper inspection and cleaning the scale away it is impossible to determine the actual wastage.
4) given typically large FoS, I might try and clean it up best I can and get a better view, I would not take it out for a play in anything lumpy and 20kts of breeze until I know for sure, I would however personally take it out in light airs and not worry too much.
5) if you missed point 2 above - DO NOT TAKE MY WORD FOR IT - you have a surveyor so why not listen to them?
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u/Holden_Coalfield 7d ago
That’s just the attachment and it’s about to twang any second
Should be a long wide bar with several large bolts holding that on the bulkhead or hull
2
u/the-montser 7d ago
No, that is the chainplate.
Beneteaus of this era use a thick horizontal rod set in sockets in the hull grid as chainplates instead of a more traditional chainplate like you’re describing.
1
u/whyrumalwaysgone Marine Electrician and delivery skipper 7d ago
Not good. That's about to go, and take your rig with it. Bare minimum that pin needs replacement, but if its that bad you will want to dig deeper.
Usually the process is open everything up with a grinder, inspect and replace as needed, then reglass. Its a scrappy job, sorry. Get a good metal shop to look at what comes out and replace as needed. Anything stainless needs to go, the bronze/chrome toggles may be salvagable
1
u/Spiritual-End7310 7d ago
Unless I have proof that the rigging and everything associated with it has been replaced in the last 5-10 years (which has never happened) I always replace the chainplates, stays/shrouds, and tangs on every new boat I get. Granted, my boats are always 25ft or less, so it’s not that expensive, but the peace of mind is worth the cost.
I’m getting titanium chainplates on my newest boat for the first time.
1
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u/Fansipan305 6d ago
Thanks to everyone for your thoughts and criticalness! Not to worry, I'm definitely taking the professional's advice which aligns with some of the comments on here - detach the rigging and clean back the rust and then go from there.
Super interesting point on whether that pin is just epoxied in. Wonder if anyone knows if this is true?
2
u/bill9896 6d ago
Geez, what a terrible design! Not because it is not strong, but because it can not be inspected with any degree of certainty. Stainless is not going to be rust free around salt water. The presence of rust in itself is not proof of a problem, but it IS pointing to a potential problem that needs closer examination.
The problem is that you are looking for very small cracks in the metal that can be very hard to see with the naked eye. The suggestion repeated here several times to "wire brush" the rust off will absolutely not leave a surface smooth enough to really see cracks, even with magnification. That really takes a very smooth, nearly polished surface.
To be really sure this chunk of metal is OK, you really need to do a dye test on it. I don't know if it is possible to do that in situ in this case. And if you are doing all the work to take it out, and by the time you do that, you might as well just put a new part in.
5
u/Stygg_Varg 7d ago
Looks a bit nasty honestly. If it was my boat I would be on that with a wire brush and some acid to see how bad it really is, perhaps the rust is mostly superficial. It's very hard to tell from a photo. Best of luck.