Composite Chainplates.

[44C]

If you're building a boat and the plans specify stainless steel for the chainplates, ask your designer about doing them in fibreglass. (You can also use carbon, but it's not necessary and you'd only save a couple of kilo's.)

It's a much better solution. Easy DIY, they'll never leak, never corrode, never need replacing. They're neater and lighter too.

I'm surprised that every designer doesn't specify them.

[dmmbruce]

Sounds logical.

I have often vaguely wondered why we always have stainless ones, embedded in the fibreglass, when lots of articles say that SS rots/rusts when not in the air.

But, since I can only consider old boats. Design considerations are well over my head.

Mike

[Peter]

If you're building a boat and the plans specify stainless steel for the chainplates, ask your designer about doing them in fibreglass. (You can also use carbon, but it's not necessary and you'd only save a couple of kilo's.)

It's a much better solution. Easy DIY, they'll never leak, never corrode, never need replacing. They're neater and lighter too.

I'm surprised that every designer doesn't specify them.

They are easy DIY but time consuming to make and maintain consistency, which is why production builders use SS. Many designers and DIYers just follow the norm.

[44C]

I'd say they'd be far less time consuming for the home builder than chasing around for heavy gauge stainless, cutting and drilling, getting nuts and bolts etc.....

With composites, you only need to buy the stainless tubing for the thimbles, everything else is material a builder would already have on hand.

[quickcat49]

I just built mine, last week, and I should mention that weight savings depends on having a weight concious designer, with confidence in the material. <br>
<br>
My chainplates took 4 liters of epoxy for each chain plate. 42 layers of 300 GSM uni, pointed in various directions. The glass was cut in the shape of a Bow tie, with a 120 cm total length, and 60 cm radius on each side and the widest part was 60 cm wide, tapered, of course. It was then layered over a ss tube and over each side of the hull. I'm quite sure that they could have been made with fewer layers, and less like a bow tie shape. It seems most designs are more like the shape of the stainless it replaces. Which, by my estimation, would have taken about one litre of resin! So I agree, especially with an aussie designer, they'd be lighter than stainless, and easy to make.<br>
<br>
I'd guess each plate has a mass of nearly 8 kg.<br>
<br>
Cheers.<br>
Paul.

[44C]

Sounds like your chainplates are massively overbuilt, which isn't such a bad thing. But in truth, they're still probably lighter than they would be if they were stainless steel. The same designer would likely overbuild by a similar factor, and remember that whatever structure the chainplates would be bolted to has to be at least as strong as the chainplates themselves.

[quickcat49]

The plans for stainless plates were also in the plans, and we're what I expected. I think it's a confidence issue. Having said that, you're right, over built isn't necessarily bad. Anyway, they're done now, and they're not skimpy! ☺

Cheers.
Paul.

[44C]

https://diy-yachts.com/forum/downloa...=231&mode=view

A well built and very strong fibreglass chainplate.

[quickcat49]

https://diy-yachts.com/forum/downloa...=231&mode=view

A well built and very strong fibreglass chainplate.

That link isn't available to the public.
Paul.

[44C]

Can't seem to link to the photo. It's on this page:

https://diy-yachts.com/forum/viewtop...=1021&start=30

[quickcat49]

Thanks Alan.
That chainplate dwarfs mine. And I thought mine had a lot of glass at 15mm! I take back what I said about confidence in the material. I guess my designer has enough confidence... Now mine's in doubt! Just kidding, there's still a minimum of 9:1 ratio of strength of the chainplate and strength of the wire.






My apologies for the blurry photos, I used my computer, and I guess it's not much of a camera. It couldn't possibly be me!

Cheers.
Paul.

[44C]

Yes, that's a pretty big chainplate! Mine are much smaller, there's probably about 10 mm of glass, and as you say huge margins of safety in that.