Questionable issues with the chain plate

[openseas]

My fellow sailors,

For eight years, I left my 30' sailboat in a dry dock in a marina.
And with the current corona situation, I found a lot of free time to go back to the sailing world.
The boat has leaked water through some ports, and the through the chain plate area, which holds the standing rigging of the mast.
The chain plate is bolted to a large triangle piece of wood, and the wood in turn is connected to the body of the the boat on each side, and ends at the wooden floor.
That piece of wood is soft now in few places close to where the chain plate is bolted. The wood is approximately 2 inches thick.

I don't like to have any future accidents due to this issue, can you please advise me about my options?

I like the design of my boat, the space, and the way it handle in rough weather, and I like to keep it if possible.

Even though, I consider myself a novice in sailing, but I know for sure that there are many of you out there that have so much experience in sailboat structure, and I will wait patiently for your feedback.

Thanks,
Andy

[Benz]

I'm sorry to tell you this, but that soft wood must be repaired. At the very least, the rotten section cut out and a new piece scarfed in. Might be necessary to extend the chainplate so that some of the bolts engage original wood; you should consult with a boat repair guy who can look at it in person and advise.

[JPA Cate]

More bad news, sorry, but I'm thinking that chainplate goes through the whole bulkheaed, not just the portion outboard of the pin rail.

Benz is right, you need to get someone who knows what they're looking at to tell you what needs to be done, and then, how to do it safely. Meantime, make sure they check all the chainplates. Water is very sneaky about how it travels, and fresh water is wood's enemy.

Ann

[Sailmonkey]

I’ll echo the previous......it’s a messy job, but if that’s really just a knee, it’ll be easier.

Disconnect the chain plate, remove the wood, replicate the wood, glass the new wood back in place.

[Bill O]

Originally Posted by Sailmonkey

I’ll echo the previous......it’s a messy job, but if that’s really just a knee, it’ll be easier.

Disconnect the chain plate, remove the wood, replicate the wood, glass the new wood back in place.

Guess you could call it a knee or a small bulkhead and would agree w/how you would do it.The OP said it was a triangle so I assume it goes down the hull behind the settee which is bonded to the hull and part of the cabinetry. Would check all of the chain plates to see if there were other bulkhead issues.



Don't think someone w/o any experience should do a structural repair as this appears. Possibly get some repair quotes since many are looking for work to do now.

[DefinitelyMe]

Another re-inforcement of previous sentiments; if it's soft it absolutely needs to be replaced. Honestly it'll be better, and probably easier, to replace the whole piece rather than trying to scarf in a section. But, there are options and it's definitely worth hearing some from someone knowledgeable.

It's just the small section, right? The cupboard is forward of the rotten bit where the chainplate attaches, followed by the main bulkhead forward of that? It's hard to see in the picture....... But if that is the case then it might be possible to pull out the rotten piece forward, into the cupboard, having cut through the glass tabbing. Then you could re-glass from inside the cupboard along the forward edge of the new bulkhead and glass sections on the after edge where you can get access through cupboards etc. If there are a few gaps in the glass along one edge it won't matter. This might look like a major problem but actually it might not be. Certainly not cause for getting rid of the boat!

[DefinitelyMe]

Oh one more thing - if the wood is 2" thick (that's very thick!) then it probably isn't a single piece. More likely two pieces of 1" ply laminated together, in which case one side might be ok. Are both sides soft?

[StoneCrab]

Check out the "Where is Brickhouse" youtube channel. Patrick did this exact repair recently.

[Exctyengr]

I will add to the chorus, you need an experienced shipwright to do this job properly. Chainplates and their attaching member are major structural elements of the boat. Don't mess with them. And, BTW, when the assembly is dis-assembled, I would consider non destructive testing of the chainplate itself. Water on the chainplate without the presence of sufficient oxygen can cause inter granular corrosion of the stainless. I have personally experienced that with the resultant fractured chainplate.
I wish I could offer a ray of hope, but this is real and a genuine safety concern. If you somehow lash this up and you loose a mast you are in for a very bad day. Good luck , keep us informed.

[Sailing Drummer]

I had some water stains on a few of the knees. I spoke to my surveyor about it and he wanted me to drill a few 1” holes to see if the water had penetrated the wood. In my case it had not. When he came to look at them he decided the best repair was to inject acetone along the inside of the holes. He did recommend tabbing over the existing tabbing because he didn’t like the way it had cured. Bottom line, in my case it was next to nothing but without the surveyor I would not have known. Get a professional to look at it.

[StoneCrab]

Originally Posted by Exctyengr

when the assembly is dis-assembled, I would consider non destructive testing of the chainplate itself. Water on the chainplate without the presence of sufficient oxygen can cause inter granular corrosion of the stainless. I have personally experienced that with the resultant fractured chainplate.

Exctyengr did you have a chainplate failure while sailing or did you catch it in time?

This is something that I have concerns about but the prospect of removing the chainplates for a look and see is daunting.

My chainplates are bolted directly to the hull but mounted on the inside surface. Only the bolt heads show on the exterior. Removing them would be a lot of work, but loosing one would be worse. Can these be electrically tested insitu? I would guess that once the granular corrosion starts it would be more resistive.

Did you have any signs that the corrosion was present?

[CF32907]

CaptVR here, Hi All
This is a bad situation. You should fire your surveyor if he in deed told you to do, what you had said. That is not considered a knee, it is a partial bulkhead. You have a number of things going on. Number 1, there is a good chance of crevice corrosion on some bolts and definitely where the chain plate passes through the deck. That partial bulkhead, looking at the deterioration will require replacement. No Dutchmans, no doubling up, no cutting out replacing a small portion. The material sandwiched in the hull tabbing and down inside the cabinetry is what supports the rigging through the chain plate.
Normally I would say, most handyman carpenters could do most bulkhead replacements, but this one is very convoluted and will come apart and go back together like a puzzle.
Over the years (55+) surveying, I inspected many dismastings and partials because of partial and full bulkheads shreading apart, the ones that did retain the rig was only because the chain plate bolts caught on the bottom side of the deck.
From the looks, this condition has been going on for some time. But to ascertain a true fix, pull the chain plate and probe the inside of the holes with an ice pick. Inspect the chain plate very closely at deck passage. If you see any type of little pin holes, replace the chain plate.
For a surveyor to tell you to drill a couple hole is absolutely un believable. The very first thing he should have told you was to pull the chain plate, no exceptions.
Wish you the best, hope I gave you some insight.
Capt. Vince Rakstis, Ret MS
PS: Best advice, higher a rigger (no dog in the fight) they are very familiar with substructures to the rigging, and can give you some sound advice on what direction to take for proper repairs.....

[openseas]

Hi all,

I went to the marina today, and this time I removed some of the rotted wood, and took some pictures, and as you can see it extends close to the plates.
I also found out that the wood extends to the level were you put the cushions, and not bellow, as you can see in the pictures. Both sides have rotted wood, close to the chainplates.
To me, the wood looks like a double plywood glued together.

-If I want to remove and replace the piece of wood on both sides, what kind of solid wood would bond better to the side of the hull?

-How can I hold the mast in place if I want to replace one side at the time, once the standing rigging is loosened?

And my last question:
-What kind of material to use, to create a good bond with the wood, and with the fiber glass of the hull?

Thanks,

[CF32907]

Originally Posted by openseas

Hi all,

I went to the marina today, and this time I removed some of the rotted wood, and took some pictures, and as you can see it extends close to the plates.
I also found out that the wood extends to the level were you put the cushions, and not bellow, as you can see in the pictures. Both sides have rotted wood, close to the chainplates.
To me, the wood looks like a double plywood glued together.

-If I want to remove and replace the piece of wood on both sides, what kind of solid wood would bond better to the side of the hull?

-How can I hold the mast in place if I want to replace one side at the time, once the standing rigging is loosened?

And my last question:
-What kind of material to use, to create a good bond with the wood, and with the fiber glass of the hull?

Thanks,

CaptVR here again,
Looking at these new photo's, replacement is probably in order. Rot spores travel with water migration, you may think you got it all and 6 months to a year you have rot forming again. All work done will require doing again. That bull sht that the surveyor told you about putting acetone in there, won't do a thing, SO RIDICULOUS, you need to find out if he is a NAMS or SAMS surveyor and call home office and report him.
Like I said in my earlier reply, there is no partial repair, this partial bulkhead requires total replacement, I would not doubt that the one on the other side is probably as bad.
Capt. Vince Rakstis Ret. MS
PS: Just pull your halyard over to a stanchion base and secure for mast support. Again, check with a rigger.

[Sailmonkey]

Originally Posted by CF32907

CaptVR here again,
Looking at these new photo's, replacement is probably in order. Rot spores travel with water migration, you may think you got it all and 6 months to a year you have rot forming again. All work done will require doing again. That bull sht that the surveyor told you about putting acetone in there, won't do a thing, SO RIDICULOUS, you need to find out if he is a NAMS or SAMS surveyor and call home office and report him.
Like I said in my earlier reply, there is no partial repair, this partial bulkhead requires total replacement, I would not doubt that the one on the other side is probably as bad.
Capt. Vince Rakstis Ret. MS
PS: Just pull your halyard over to a stanchion base and secure for mast support. Again, check with a rigger.

Hey CaptVR, Sailmonkey here......

You’re mixing posts. The OP didn’t have a surveyor tell them anything....