Builders' Forum Archives

Re: Hidden Footbrace Moun

Posted by Laszlo on Jan 12, 2008

George wrote "I suspect it's more durable than a 'through the hull' application..."

It probably is. The through-hull bolt is concentrating all the stresses on the front edge of the hole and the area under the back half of the bolt head. The CLC hidden bolt base is bedded in epoxy putty and covered with a glass patch that's a few inches square, so the forces are distributed over a very much larger surface area.

Also, the hole through the hull breaks the wood fibers in every layer of the plywood, while the hidden mount leaves them intact. Beside reducing the hull strength by some small amount, it also leaves exposed grain to wick up water if the epoxy every cracks, say because someone is pressing a piece of metal against it with their foot.

As George says, I've never heard of one failing either, but on general principles the hidden mount makes so much more sense to me.

BTW, The tape in the picture is to keep the threads clean.

Laszlo