The rabbet is a groove cut into the keel where the frames and keel meet. This gives a solid footprint for the bottom planking to seat into as well as providing a caulking seam. On a Buehler boat this can be done very easily before you attach the frames by running a skill saw along the rabbet line you have marked from the patterns. The angle won’t be perfect the whole way, but because there is little change in the angle of the frames this can easily be corrected later with a chisel. Unfortunately I made it much harder on myself… When we built the keel we bought lumber that was supposed to be nice and dry, but that turned out not to be the case. Since the lumber wasn’t as dry as it should’ve been the keel developed a slight twist in the back where all the timers are stacked high. Because of this my paranoia persuaded me not to cut the rabbet before attaching the frames fearing this might cause the hull to come out funky… Instead I decided to attach all the frames to there predetermined position with clamps, check the hull with battens, levels, and eye. That way we could correct any issues before bolting them down. Well that was the theory… It turned out the hull was fine. The twist in the keel was so insignificant it made no noticeable difference, which is good but now I have to cut the rabbet the old fashion (time consuming) way.
I start by bending a batten along the rabbet marks to get an outline of the rabbet. Next I cut a small section of the rabbet at each frame. This gives me the correct angles and depths. Then I cut in the rabbet between frames using the notches to help me eye the cuts as I go.
It’s a slow tedious process, but were chippin away…
Thats it for now!