Thursday, February 26, 2009

Second row planking

The second row of planking is much easier to work on. It don't have the huge curve at the front like the first row. But it does have it's own areas that need attention paid to. One is the lower edge of the exposed plank, this will be the edge seen by the critical eye. It must be a clean fair line continuous to the rear of the boat. The other is the front. To look right in my mind the plank at the Stem should gradually go flush with the plank below. I'm using a "Ship lap", beveling off so much from the top plank and so much from the bottom plank over about 400mm. The line or notch will go from a full thickness of the plank at the rear, to a half thickness at the stem of the boat. This is done for both planks. Using the template and dividers as before, I cut the forward plank and made sure the bottom edge had a clean line or fair curve. Being a picky sort on some issues, I was determined to make both side of the boat look as close as possible to mirror images of each other, So I cut the opposite side plank from the first. My thinking is that I cut the frames identical on both sides, they were built symmetrical, the slots are in exactly the same spot and depth, and the stringers are in the same place. So why wouldn't it work.
The plank was then dry fitted. I used my little measuring device to find how far down the overlapping plank would be and scribed a line along the length of the boat. The depth of the stringer basically.
The plank was dry fitted and marked where I was to start the lap cut to the stem.
A "Ship lap" joint is usually done with a chisel (difficult) or by using a Rabbet plane. I picked one up for this job actually and was using it to make my lap, but it was taking too long. After 15 minutes of this manual labor, my laziness kicked my brain in gear for a quicker easier way to do this. I knew a chisel was out of the question so I looked at my power plane... mmm
The motor casing is about 1/2" above the deck of the planing surface... promising. The depth needed to achieve is only 3/16" or half the plank thickness, and a thin piece of wood clamped in place to keep the planer on track would do the trick. Sure enough in no time I had both laps done and very cleanly too. Another test fit and I was sold. Manual plane back on the shelf. That's another item covered that I thought could cause problems. "Ship lap" done.
The plank was screwed in place temporarily and the next one back was "templated" and cut along with it's opposite side partner. Likewise the rear short plank section. The lower planks top edge was planed down with the grinder and belt sander to make a clear overlap for the plank above. As before I screwed the planks in place temporarily and glued the scarfs. This time though I had a block of wood to distribute the load on the screws and make for a cleaner scarfed joint. wax paper kept it from being a permanant part of the boat. The exess epoxyt will be trimmed off after.The whole long plank was then removed and the bottom finished edge was cleaned up.
The whole thing is then glued and screwed in place. The same for the opposite side.

Time: 10 hr over 5 evenings

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