Chainplate R&R on a 1979 glass hull

[Marpessa]

Looks like I had better open these up and take a sample of how much corrosion is going on inside...the boat still sails great - but this looks like a potential trouble point.

Does anyone know why chainplates get encapsulated in glass and hidden behind bulkheads??

These chainplates are cap-rail entry into the hull. The bolts are weeping rust onto the gelcoat on the outside so I may be lookiong at crevice corrosion, etc. I don't believe I can convert to outside hull mounted chainplates because of the caprail and rubrail outside on hull. So it's a straight R&R.

The pics here are of the easy access chainplates in the cabinets. On another I will have to cut away finish mahogany in the cabin (OUCH OUCH!!)...

...Then there's the one in the rear corner of the hanging locker forward that my back is sure to never recover from.

Any ideas or experiences are much appreciated. If you have done this project and have some advice on how to cut away the fiberglass and get these out of here I'm all ears. For now I'm just going to chop at it with the angle grinder until I strike stainless - wish me luck.


Thanks!!

[Jon Neely]

If you think you can remove them then go for it! Our Hc33 had glassed in plates but with no way to cut them out without compromising the hull. We opted to both through the existing plates and have external bronze plate. Just wrapping up the project as we speak in mexico.

[Nicholson58]

Originally Posted by Jon Neely

If you think you can remove them then go for it! Our Hc33 had glassed in plates but with no way to cut them out without compromising the hull. We opted to both through the existing plates and have external bronze plate. Just wrapping up the project as we speak in mexico.

Many have opted for external plates as a way out. Certainly an OK option.

We replaced our main chain plates with GR 5 titanium. See our photos here, Member Galleries - Cruisers & Sailing Photo Gallery The plates are so hidden that titanium & no future inspection was preferred.

[roverhi]

That is some ugly stainless steel. I would try and figure out a way to notch the cap and rub rail so you can put them on the outside of the hull. Leave the old ones in place as backing plates for the new fasteners. Failing that, install new chainplates over the old ones on the inside if you can't cut them out.

[Marpessa]

Originally Posted by Jon Neely

If you think you can remove them then go for it! Our Hc33 had glassed in plates but with no way to cut them out without compromising the hull. We opted to both through the existing plates and have external bronze plate. Just wrapping up the project as we speak in mexico.

What year is your Hans? Mine is a Union Polaris built in Ta Shing boatyard in Taiwan. We may have very similar constructions depending on your year. Mine is the Bob Perry design that the yard stole from HC and built a run of them starting in about '78.

What made you think you would compromise the hull by pulling these out? it seems like a very thin layer of glass covering the plates on my build...almost an afterthought rather than a structural feature. I've heard using the old plates as backing doesn't always help if they're really shot. I guess each case is unique. Can you connect bronze and stainless together via the through bolt with no electrolysis issues?

Also, as an afterthought, the existing plates on mine have only 3 bolts that pass through them, there is no sandwich with a backing plate. The bolts enter the hull from the outside and pass through the chainplates and nuts nuts on the inside. I'm thinking the whole system may need revised and re-engineered. Oh crap - Now I've said it...

[Jon Neely]

our hc33 is a 1982, built in the Hansa yard in Taiwan. The 33 was pretty unique with this yard and I believe only a couple of HC43 and HC48 where built there until production moved in 86'. Our Plates go down the hull 12'' and are welded together with a horizontal bar that connects all three on both sides in about 4'' of fiberglass. To remove ours would require removing a ton of glass and a good 6' portion on our beam. There is one boat that I know of that has done so and they approached from the outside to do it. They Replaced the horizontal bar, inspected the plates and reglassed and painted. Our new bronze Plates will not be sitting in water so non similar metals is not a big concern of mine. There are a lot of bronze fittings with SS fasteners on our HC that are now 30 years old that show no signs of corrosion issues.

[Marpessa]

Originally Posted by roverhi

That is some ugly stainless steel. I would try and figure out a way to notch the cap and rub rail so you can put them on the outside of the hull. Leave the old ones in place as backing plates for the new fasteners. Failing that, install new chainplates over the old ones on the inside if you can't cut them out.

Interesting approach - I've heard it said before but I want to see it in practice. The logistical hurdle I see with this idea is: how to drill the holes precisely on the new plates when I can't remove the old ones as templates. I guess maybe build some woodies and scribe, cut, scribe, repeat...

If you think about it, every bolt must have equal purchase and contact with the plate and be snug in the hole; or else you're relying on the strength of a smaller portion of the steel...which is maybe why I've been seeing pictures of cracked chainplates...even though not much rust/deterioration present. Just a thought.

Thanks for the reply!

[Lepke]

Looks like ferrous metal to me. It was built that way because they build, not repair. The glass over was a cheap way to avoid corrosion and buying more expensive metal. From the builder's viewpoint, he's never going to get to the brackets again. I would take them out and replace with stainless 316. They will continue to rust away and then your bolts will be loose. Considering what chain plates do, failure could be very bad. The hull needs to be clamped tightly between the chain plates and these brackets.
If you have a multi-tool with a saw type blade is the easy way. Cut around the bracket and the glass should peel off. It's probably poly resin and doesn't stick to anything well. A multi-tool would make the plywood cuts faster, too. The cut-off blade on a drill motor is slow because a drill runs at a fairly slow speed. Those blades are made for much higher speed and for cutting metal.
Harbor Freight has a cheap multi-tool and it's probably on sale now.
To patch the cabinet back, I would put a 1/4" piece of new plywood over the entire back. Fill the edge seams, paint it and no one will ever know.

[reed1v]

i redid all the chainplates on two Cheoy Lees. Cold chisel with hand held sledge hammer had to be used to cut away a lot of the glass bonded around the plates.

[Rick Williams]

We just replaced all the chainplates on our DE 38 which were all inside and came up through the caprail. We patched the caprail, used the old units as backers for the new 316 chainplates on the outside. We used the old units as templates for the new ones so the holes lined up.
We use a tool called a Fein tool or a multi tool where the angle grinder is too aggressive. It will do plunge cuts through almost anything very quickly and make accurate cuts in fiberglass with very little collateral damage and they're not very expensive anymore.

[Marpessa]

Originally Posted by Rick Williams

We just replaced all the chainplates on our DE 38 which were all inside and came up through the caprail. We patched the caprail, used the old units as backers for the new 316 chainplates on the outside. We used the old units as templates for the new ones so the holes lined up.

We use a tool called a Fein tool or a multi tool where the angle grinder is too aggressive. It will do plunge cuts through almost anything very quickly and make accurate cuts in fiberglass with very little collateral damage and they're not very expensive anymore.

Thanks for the reply!

So, you were able to get the old chainplates out of the hull? How difficult was that? I ask because maybe I can just unbolt mine and slide them up and out...not likely but saves days of chipping away the little layer of glass on the inside.

...it seems to me the plates will get damaged possibly if they don't want to come out. Or I get stuck mid project having to figure out major surgery. Kinda scary.

Also, if you say you used the old units as backing plates, while also filling the caprail slots, I'm assuming you cut some off the top of the old chainplates and then slid them back down into their spaces, is that correct?

Just out of curiosity, what did you fill in the voids on the caprail with?

Thanks again!


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[barnakiel]

Originally Posted by Marpessa

Does anyone know why chainplates get encapsulated in glass and hidden behind bulkheads??

This is boat specific. On our boat they are not.

If (=when) you cut off the outer layer of the fiberglass, try to make sure whether the extra glass was 'structural' (adding to the strength of the chainplate to hull bond), or not. If in doubt, make the chainplate knees stronger by adding some glass.

I think we call it chainplate blues.

b.

[Rick Williams]

I hate to be the bearer of bad news but those look like a real liability so I think you just have to bite the bullet and get them out. I can't imagine they have much integrity left and I'd hate to lose the rig to something I was suspect of to start.
We used a stainless cutting blade on a small angle grinder to (easily) cut the tops off the existing chain plates after we used them for patterns. We used a cheap hydraulic press (from Harbor freight and cheap) to bend the new plates into the right shape and filled the holes in the cap rails with teak plugs and epoxy.
We made a "dutchman" pattern for the plugs in plywood and used a router with a guide in the plywood pattern which took a couple hours to set up but then the process went very quickly and the patches came out barely noticeable. If you pick your grain carefully and do the fitting of the plug carefully, the joints will be very small.
If you ever have a question about anything, look it up on youtube and think of how great you'll feel as you conquer each task!
Be fearless! The boat will appreciate it and take care of you when you need it to.

[Boatyarddog]

I'd use a multi tool, and just get to doin it, Taiwan built boats are full of this kind of construction.
It's ok though, when your done you'll know you good to go.


Sent from SV Cloud Duster

[Marpessa]

Thanks all, I'll post some pics as the project goes on.