I have been reading about scarfing plywood for as long as I’ve been building boats, but I’ve never done it.
The idea of hand-cutting a square 12:1 edge along a sheet of plywood just seemed impossibly impossible.
But today I had no choice.
The lay-ups for the rudders for the Tiki 38 are too long to fit on one sheet of plywood, so smaller pieces need to be scarfed together to make up the length.
And since this is the rudder, a part of the boat that takes all the steering stress when the helm is put over hard, or a wave shoves the boat, there’s no cheating with with butt-blocks or some such. A scarf is as strong or stronger than the ajacent material, so a scarf it has to be.
My shop mate Dave was skeptical. He’s got a lot of practical experience with wood-working, but mostly of the building and fixing houses kind. Plywood scarfing does not come up in this sort of work.
I assured Dave that I had been assured that it’s actually very easy if you just mark things off properly and take you time. But still, the plwood we were working with (18mm “Hydrotek” brand BS 1088 meranti) goes for about $120/sheet, and it’s not available locally. If I screwed it up, it would be an expensive hassle to get more wood, and then I’d still have to do it right.
It turns out it is easy.
A great way to finish off a very productive week at the boat-shop!