1983 Hunter Cutter 37 Chain Plates

[Johnb]

I have a quote for replacing my standing rigging. They declined to quote for chain plate pull and inspection. I am thinking about doing at least the lowers myself before taking it in. If they go easy I might do the uppers as well.
Question - has any other HC 37 owner had experience with this job? Any particular difficulty?

 

[Jim Legere]

Hi John, I just pulled the chain plates on my boat, for the second time since I purchased the boat. Its as easy as unscrewing the escutcheon plates and then removing the five bolts below decks. You will need a second pair of hands for the forward lowers. Both times I removed the chain plates, it was for resealing, but I gave the them a thorough inspection while they were out. There was some very minor staining/pitting where leaking water had started a bit of pitting corrosion but polishing the chain plates with 120, 220, 400, 600 & 1000 grit sandpaper and finally rubbing compound brings them back to a near-mirror finish. The first time I crack inspected them using a dye penetrant system but this time I just used a 10X loupe and I am confident there are no cracks. Pay attention to the area that penetrates the deck as well as the area around the topmost bolt hole. The first time I re-bedded them, I used polysufide caulk (LifeCaulk); it was probably pretty good for three or four years. Eventually the bond between the caulk and the wood coring of the deck failed - it was still adhering well to the chain plates. This time I went all out. Using a zip cutter as a small router, I cut back the deck openings to clean core with a 3/8" core box bit. I taped the holes closed below decks and filled the openings with thickened epoxy. Using one of escutcheon plates screwed into the original screw holes as a template , I routed out the slots in the cured epoxy with a 1/4" zip cut bit. They are now a much closer fit around the chain plates (the original holes were uneven & messy and the wood core was exposed). This time I purchased a roll of Bed-it Marine Butyl Tape and followed Maine Sail's excellent advice for bedding deck fittings in butyl. I am pretty confident I will never have to do this job again. I will put some pictures up soon in the "Owner Modifications" section here at SailBoatOwners.com. Oh yeah...and I did all this with the mast up. I just moved the shrouds out to the toe rail. Feel free to PM me if you want to chat about it.

 

[Johnb]

Jim,

Thank you for the write up. We are going to go to the boat tomorrow and stay until Tuesday the 4th. I am going to make a start on this job. I will let you know how it goes, thanks again.

 

[sailnc]

+1 on the butyl tape. Just did our 3 starboard chainplates -- they were leaking and causing damage to the wood trim below. The butyl was easy to work with and I haven't seen any signs of leaks since, even with our heavy summer rains. Port side isn't leaking, yet, but I'll be doing those too.
Tom

 

[Johnb]

Jim et al,
I have the 4 lowers out and am waiting on butyl tape and new spring washers to re install this weekend. The picture shows the only corrosion anywhere on any of the 4. It is right where the plate was inside the deck and is about 1/8" by 7/16" and by comparison with a feeler gauge about 2/1000" deep max. I am going to assume that it is no problem to just put back into service. Would appreciate comments. Overall I am pleased and quite surprised at how good these 38 year old chain plates are.
The job was very easy and I am going to remove the uppers for inspection during the up coming rigging replacement. Thanks again for your advice.

 

[Jim Legere]

John, I am not a rigger, engineer or lawyer, so take my comments with a grain of salt . I had at least one chain plate that looked like that and I just cleaned it up the best I could with various grits of sandpaper culminating at 1000 grit. The idea for this was to eliminate as many pits as possible where water could collect in the future. But if you are resealing with butyl tape, the likelihood of water even getting to it is small. As far a strength goes, the loss of .0002" is pretty minimal, IMO. I think a greater risk would be posed by the beginning of cracks in area of the bolt holes; I did not see any cracks on mine. So my advice would be to put that chain plate back in and forget about it...and that advice is worth every cent you paid for it!

 

[dLj]

If it were my chain plate, I'd polish out the pitting and then reinstall it. I do like all of Jim's disclaimers... My main disclaimer is I can't really see the full extent of the pitting you have, so my advice is also worth what you've paid for it...

dj

 

[jssailem]

John, I did grind and polish my plates. There were not showing the pitting you have.
You need to understand the level of corrosion that is happening. You have some trace pittig on the op site side of the area marked in your image. You have a few spots under the rust stains and on the weld. This is like a cancer on stainless. Anywhere it appears it needs to be removed back to solid metal. I you can not find bright shine metal then a new plate is in your future. Once the grind and polish is accomplish you need to thank them to a chemical house that can neutralize the steel. This is dunking the steel in a hot acid bath to stop any unseen corrosion or at the least slow it down. If you find you have to take a lot of metal to grind away the pits, then new chain plates are answer.
Good luck.

 

[dLj]

jssailem is giving you great advice! Polishing the plates is definitely the thing to do - polishing is a key word. What he is calling 'neutralize' is technically called passivation. You should ask the place if they can passivate your plates to either ASTM A380 or ASTM A967.

That being said, if you don't decide to send your plates out for passivation, it likely won't be a deal breaker, the austenitic stainless steels tend to self-passivate on their own.

dj

 

[Johnb]

Thanks for all the good comments,
John