I just reduced the molds; why cut all those notches? If you notch the molds, the notch should be wide enough to wiggle the ribands around a bit so they lie in fair curves. I don't trust my lofting to define the plank lands that accurately, so I fiddle with the riband positions, some might say compulsively.
The riband should be just about the width of the lap, so that (with the hull upside down) the lower edge of the upper plank lies on the lower edge of the ribband, and the upper edge of the lower plank lies on the upper edge of the ribband.
I don't trust the ribbands not to bow when using a router to trim the planks, and an unfair curve along a plank edge will look really lousy. I do the following:
- Clamp the plank stock to the mold.
- Trace along the ribands with a pencil. Note that you have to mark the plank BEFORE the previous one is glued up.
- Take the plank stock off the mold
- Cut just outside the line
- Use the rough-cut piece as a pattern for the opposite-side plank
- Clamp the two planks together
- Plane the plank edges to a fair curve, hopefully one close to the line, but a good line takes priority. Nice plank lines are more important than constant width laps.
One has to be careful with the portion of the plank between the first mold and the stem. The riband won't bend fair in this area because the end is unsupported, and if you're not careful you'll get droopy-looking plank ends. I make the riband long, run it out past the stem, establish (by eye) where the plank edge will fall on the stem and mark it, and then cut the riband short, usually right at the first mold. You have to pay particular attention to this area when planing the plank edges fair. For boats with transoms, I build a sort of pseudo-mold inside the transom to which I can fasten the ribbands.
"For a successful technology, reality must take precedence over public relations,
for nature cannot be fooled."