Well, I thought I was being really clever last weekend. I jury-rigged a fancy router jig to cut the 1-3/8" x 30" long gains on my lapstrake build. Worked like a charm for the garboard planks - which had a straight edge to work from.
Moving on the next pair of planks, my system worked okay for the gains at the aft ends of the plank, which had a fairly straight edge to work from. But the forward ends are another matter entirely. The curve at the forward ends of the planks prevents my fancy jig from working.
What I did was to clamp the plank upright, on edge. Then I clamped a straight piece of 2x material to the plank, flush with the top edge of the plank, just to give me a wider base to work from. Next, I clamped a piece of 1/4" cold-rolled steel to the (now 2-1/4" wide) top surface. I aligned the edge of the steel with the start (flush with the outside face of the plank) and end (flush with the inside edge of the plank) marks and clamped it into place.
Next it was a relatively simple process of running a bearing-guided straight bit along the edge of the steel to cut the sloping rabbets. As I said, this setup worked fine as long as the plank edge was straight (or nearly so).
All of this was necessary because I do not have a rabbet plane. Which brings me to the actual point of this rambling post: How do you people cut gains? Has anyone built the "gain-o-matic" jig and could share some photos? I think since it works by routing from the face of the plank, the curved edge wouldn't be a problem, but I can't find any decent photos of the thing and I don't have a copy of the book.
Any other clever ideas would be welcomed. I tried using a regular plane, but I'm going to tear up the plank, the plane, or something else out of sheer frustration if I continue down that road.