External chainplate backing

[GILow]

I am switching the Kelly Peterson 44 to external chainplates. The job has commenced with no snags, and the old manky timber knees are being consigned to the bin, one by one.

Now, originally I was intending to use the old chainplates as backing plates for the new chainplates, but I figured it would be wise to seek some input.

I’m considering the merits of simply reinforcing the area with more fibreglass vs straight stainless plates vs some kind of right angled knee style setup made from stainless.

The KP44 hull is about 12 mm of solid fibreglass at this point on the hull. The chainplates were originally 50 or 65 x 10 mm bar with five bolts per plate.

What would you do? Fibreglass reinforcing, reuse the old plates inside, weld up a right angle bracket, or something else?

Matt

[Benz]

A half-inch of solid glass hull is a pretty good start.
I'd just use the old chainplates as backers.
More glass can't hurt, if you can get to a large enough area to make spreading the load meaningful, but unless you have reason to doubt that the hull is sound, it's not worth the bother.

[neilpride]

Dumb question, why don't you use the old timber knees as backing plates?

[phorvati]

Order G10 from McMaster. Or polish the old ones on a bench wheel to take rust off, if any. G10 is expensive but very good.

[GILow]

Originally Posted by neilpride

Dumb question, why don't you use the old timber knees as backing plates?

Wrong orientation plus they are basically fibreglass pockets of condensed wood rot.

[GILow]

Originally Posted by Benz

A half-inch of solid glass hull is a pretty good start.
I'd just use the old chainplates as backers.
More glass can't hurt, if you can get to a large enough area to make spreading the load meaningful, but unless you have reason to doubt that the hull is sound, it's not worth the bother.

Ok, one vote for my original plan.

[GILow]

Originally Posted by phorvati

Order G10 from McMaster. Or polish the old ones on a bench wheel to take rust off, if any. G10 is expensive but very good.

I hear good stuff about G10. But yes, pricey.

[Benz]

Originally Posted by GILow

I hear good stuff about G10. But yes, pricey.

If the hull has any bend, the G10 won't take it, and you'd have to "pot" then in filler. The old chainplates will conform to the hull shape when you crank down the bolts.

[GILow]

Originally Posted by Benz

If the hull has any bend, the G10 won't take it, and you'd have to "pot" then in filler. The old chainplates will conform to the hull shape when you crank down the bolts.

Good tip, thank you. There is some curve there, not a lot, but maybe enough to be an issue.