It's time to install the bottom on my 63 seacoaster. The boys at Clarkcraft here in Buffalo advised me of an easy way to scarf the 3/8 ply together.
He said to cut and peel off one or two layers of the plywood back 12" or so and do the same to the opposite board. then epoxy the two sections back together. He said that gluing layers together is how the plywood is made in the first place. It sounds easier than trying to grind off an angled edge to match.
Please advise. Thx.
Scarfing bottom Plywood
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Phill Blank
- Posts: 412
- Joined: Thu Jan 05, 2006 4:20 pm
- Location: Hurley, Wisconsin
Rong,
When one scarfs a joint on plywood or boards, the main reason for the long tamper on each half is to expose more of the wood to the glue therefore making for a stronger joint.
The only downside I see with what they suggested is the possiblity of there being a weak point where the two square edges meet. At this point you do not have over laping individual layers as you have in plywood. You only have a butt joint for half of the overall thickness of the plywood sheet. With a scarf joint each layer of the plywood has a long glue joint for a stronger bond. With all of the flexing that happens in a hull when riding over the water surface I would perfer the strongest joint I can have between my feet and the water below me.
If one the plywood was being used in an area that was less susstible to stress I would think the half lap joint would work fine, but not on the bottom of the hull.
Anyway those are my thoughts on this.
Good Luck,
Phill
When one scarfs a joint on plywood or boards, the main reason for the long tamper on each half is to expose more of the wood to the glue therefore making for a stronger joint.
The only downside I see with what they suggested is the possiblity of there being a weak point where the two square edges meet. At this point you do not have over laping individual layers as you have in plywood. You only have a butt joint for half of the overall thickness of the plywood sheet. With a scarf joint each layer of the plywood has a long glue joint for a stronger bond. With all of the flexing that happens in a hull when riding over the water surface I would perfer the strongest joint I can have between my feet and the water below me.
If one the plywood was being used in an area that was less susstible to stress I would think the half lap joint would work fine, but not on the bottom of the hull.
Anyway those are my thoughts on this.
Good Luck,
Phill
Sounds like really poor advice to me. I do not know what Clarkcraft might be, but I would not do what they advise.
Scarf the plywood together properly. There are plenty of "how to do to" at www.woodenboat.com in the discussion forum.
Andreas
Scarf the plywood together properly. There are plenty of "how to do to" at www.woodenboat.com in the discussion forum.
Andreas