Composite Chain Plates - Has Anyone Tried This?

[johnnyL]

Hello Everyone,


I’m curious if anyone here has experience making composite chain plates similar to the ones used in the Duracell project. I’m considering doing this on my 35-2 and would love to hear about any insights, tips, or challenges you’ve encountered with this type of setup.

Any advice, resources, or feedback would be greatly appreciated!



~Johnny

35-2
"Fuzzy Logic"
Duluth MN

 

[ConchyDug]

Seems like they'd be hard to inspect. Visually an advanced composite could look ok but you wouldn't know until you did an ultrasound or x-ray. You could do a tap test but that isn't a guarantee. Also the securing hardware if stainless will suffer from corrosion if using carbon.

 

[frick]

Composites are stronger then steel, but they are prone to catastrophic failure when pushed or pulled past their limits.

 

[johnnyL]

Seems like they'd be hard to inspect. Visually an advanced composite could look ok but you wouldn't know until you did an ultrasound or x-ray. You could do a tap test but that isn't a guarantee. Also the securing hardware if stainless will suffer from corrosion if using carbon.

I was thinking of using Dyneema or poly bushings like the ones used on upper lower control arms on trucks/SUVs to separate stainless to carbon corrosion. I was going composite to mitigate leaking to my bulkhead. I was figuring since I have a fiberglass boat it might work and less susceptible to corrosion.

 

[ConchyDug]

Yeah the bushings would work to stop that, I wonder if using aramid fiber would allow you to forego the bushings. I watched the video Duracell had on the checkstays, it's interesting. Would be cool to see how you would tie shroud chain plates to the structure/hull on the Ericson. If you're capable of doing the load analysis and a mock up on Solidworks that would be cool to look at. I think some here have went the titanium route. I'm in the high grade 316 camp as it seems most cost effective for an old 80s displacement design. If it was a newer design racer I'd be all about experimenting. I have pondered the idea of using the dyneema strops that go thru the deck for sail control anchor points.

Ropeye, Dynemma Loop

Buy Ropeye, Dynemma Loop ROL40 , sailing gear, sailboat parts, sails and running rigging at Vela Sailing Supply. Technical support, customer service and product information. Vela and sailing supplies.

www.velasailingsupply.com

 

[David Vaughn]

When we thought we might have to replace our chainplates, I ran across this video from Mack Yacht Services in FL. No affiliation or endorsement. It's not a complete composite solution but it's an interesting option to the glassed-in plates that some 70s and early 80s Ericsons models have. Though I imagine the cost of them doing it would make me look for a different boat.

 

[Loren Beach]

I recall that the chainplates on this model pass down thru the deck and are bolted to bulkheads inside. The original material was SS, and can be weakened by unaddressed leakage from a failed seal where it passes thru the deck.
Even if the original SS is not noticeably affected by corrosion, I would guess that passage of time might indicate a need at some point to replace. Maybe.
IF you get 40+ years out of the originals, it seems reasonable to replace with SS. If you want more freedom from corrosion replace with Titanium.
Just for a hobby and getting some experience with higher-tech parts, you could make 'em out of carbon composite, but this might take more money and time than most of us would devote. Do you have access to the engineering and layup expertise to be Real Sure that your composite replacement will be as good?
And, to address the "elephant in the room" since we are considering a 35-2, have the existing chainplates been pulled and the deck coring in that area filled in with thickened epoxy? Are the interior bulkheads 100% solid with zero moisture damage? This is important no matter what you make the chainplates out of.

Keep us in the loop. Interesting stuff!

BTW, nicely produced video, on the whole. It left out the begged question of why water was allowed to drip down around the deck penetration for what must have been years or a decade. Besides the wasting away of the metal there was a lot plain old rust evident.
As we found when we pulled all of our deck hardware off for our recent re-fit, at about 30 years even the best factory sealant is starting to fail. The lady in the video was perhaps not aware of this, and may be starting to have more hardware leak/corrosion problems all around her boat. (?)

 

[Drewm3i]

KISS: Don't overthink it. Go with stainless or titanium. You're asking for trouble and experimenting with your own potential misfortune--why?

 

[johnnyL]

Yeah the bushings would work to stop that, I wonder if using aramid fiber would allow you to forego the bushings. I watched the video Duracell had on the checkstays, it's interesting. Would be cool to see how you would tie shroud chain plates to the structure/hull on the Ericson. If you're capable of doing the load analysis and a mock up on Solidworks that would be cool to look at. I think some here have went the titanium route. I'm in the high grade 316 camp as it seems most cost effective for an old 80s displacement design. If it was a newer design racer I'd be all about experimenting. I have pondered the idea of using the dyneema strops that go thru the deck for sail control anchor points.

Ropeye, Dynemma Loop

Buy Ropeye, Dynemma Loop ROL40 , sailing gear, sailboat parts, sails and running rigging at Vela Sailing Supply. Technical support, customer service and product information. Vela and sailing supplies.

www.velasailingsupply.com

I do have access to SolidWorks, so I can work on some load analysis and mock-ups to see how everything ties into the structure and hull of the Ericson 35-2. The 316 camp and titanium definitely seem like the most economical options, but I’m here to explore all possibilities and gather as much insight as possible. The idea of using Dyneema strops for sail control anchor points is really interesting. I’ll definitely check out the link you shared. Since I stay long-term/cruising life on the 35-2, taking the time and investing in this project feels like a worthwhile cause, not to mention a great learning experience. Appreciate the input and looking forward to any other ideas or advice!

 

[johnnyL]

When we thought we might have to replace our chainplates, I ran across this video from Mack Yacht Services in FL. No affiliation or endorsement. It's not a complete composite solution but it's an interesting option to the glassed-in plates that some 70s and early 80s Ericsons models have. Though I imagine the cost of them doing it would make me look for a different boat.

Great video! Thank you for the insight. I'll add that to the list of possibilities.

 

[johnnyL]

I recall that the chainplates on this model pass down thru the deck and are bolted to bulkheads inside. The original material was SS, and can be weakened by unaddressed leakage from a failed seal where it passes thru the deck.
Even if the original SS is not noticeably affected by corrosion, I would guess that passage of time might indicate a need at some point to replace. Maybe.
IF you get 40+ years out of the originals, it seems reasonable to replace with SS. If you want more freedom from corrosion replace with Titanium.
Just for a hobby and getting some experience with higher-tech parts, you could make 'em out of carbon composite, but this might take more money and time than most of us would devote. Do you have access to the engineering and layup expertise to be Real Sure that your composite replacement will be as good?
And, to address the "elephant in the room" since we are considering a 35-2, have the existing chainplates been pulled and the deck coring in that area filled in with thickened epoxy? Are the interior bulkheads 100% solid with zero moisture damage? This is important no matter what you make the chainplates out of.

Keep us in the loop. Interesting stuff!

BTW, nicely produced video, on the whole. It left out the begged question of why water was allowed to drip down around the deck penetration for what must have been years or a decade. Besides the wasting away of the metal there was a lot plain old rust evident.
As we found when we pulled all of our deck hardware off for our recent re-fit, at about 30 years even the best factory sealant is starting to fail. The lady in the video was perhaps not aware of this, and may be starting to have more hardware leak/corrosion problems all around her boat. (?)

Yeah, the chainplates on the 35-2 pass through the deck and bolt to the bulkheads. They’ve already been replaced by the previous owner, but there’s still some moisture damage. The coring doesn’t seem to have changed much, but I’m keeping an eye on it in case it gets worse.

I agree, after 40+ years, replacing the original SS with new SS or titanium makes a lot of sense. Titanium’s corrosion resistance is great, but like you said, it’s about balancing time, cost, and practicality. I’ve also been toying with the idea of composites—not just as a learning experience but also to try out some higher-tech options. Of course, I’d need to make sure the engineering and layup are absolutely solid before committing to that route.

That video really drives home how important inspections and maintenance are, especially to catch stuff like prolonged leaks. I’ve definitely got some leaks to deal with, so I’m looking at ways to fix and mitigate that as part of this project.

I’ll keep everyone posted as things progress!

 

[johnnyL]

KISS: Don't overthink it. Go with stainless or titanium. You're asking for trouble and experimenting with your own potential misfortune--why?

Fair point! I’m in IT, so looking at all the options and exploring possibilities is kind of second nature for me. Software like SolidWorks is in my wheelhouse, so part of this is about gaining some learning insight and experimenting within reason. I definitely get that stainless and titanium are the safest bets, but it’s interesting to dive into the “what-ifs” and see what’s possible.

 

[Drewm3i]

Fair point! I’m in IT, so looking at all the options and exploring possibilities is kind of second nature for me. Software like SolidWorks is in my wheelhouse, so part of this is about gaining some learning insight and experimenting within reason. I definitely get that stainless and titanium are the safest bets, but it’s interesting to dive into the “what-ifs” and see what’s possible.

Good stuff and makes sense, but one thing to consider: these are in no way "high-tech" boats. If they were, I would be more inclined to experiment.

 

[johnnyL]

Good stuff and makes sense, but one thing to consider: these are in no way "high-tech" boats. If they were, I would be more inclined to experiment.

I get what you’re saying, but I don’t mind making these vessels high-tech in my own way. While something like carbon fiber chain plates might not exactly be a "simple improvement," I see them as an opportunity to explore better options with potential benefits like less corrosion, reduced weight, and increased strength.

Since I "long-term cruise," I can justify directing my income toward the vessel without feeling guilty. Plus, I got my 35-2 at a very reasonable price, so I’m convincing myself that all this work is building equity... at least that’s what I’m telling myself!

I’m in IT, so I tend to high-tech everything. I’ve added OpenCPN mods, RTK GPS, multiple forms of digital communication, and analog systems as backup. It’s just how I approach things.

Also, I figure that sharing the insight I gain, whether from successes or failures, could be beneficial to others. Asking "what if" questions, trying new approaches, and gathering perspectives from others is all part of the process for me.

That’s why the name of my SV is "Fuzzy Logic". It means more than one thing to me!

~Johnny