Well I got the new 1 1/4" cocobolo plane all made up, and after a bit of tuning it was flat and square and sharp and taking beautiful shavings off the test piece of elm. Also got the old 1.5" jatoba plane similarly tuned.
However, when it came time to plane the big elm pieces for the bookcase panels I ran into some problems. I could not get consistent shavings. Sometimes I would get nothing, other places it would work fine. I finally realized that with these wide pieces, they are not perfectly flat. Rather they are cupped, just a little bit, but enough that the plane will sometimes not make a shaving.
My fallback was my antique Stanley 112 scraper plane. After some tuning, I got a good hook rolled on the blade, got the blade set square, and started taking some beautiful shavings. It is a bit of work pushing it the whole length of the board without stopping. Waxing the bottom helps a lot, but I almost need to take a running start!
I might also see if I can hold the boards down flat on the workbench, so that the planes work better. I have to be a bit careful now, as these panels will fit into grooves that I have already cut in the frame pieces, so I don't want to take the panels down past a good fit in the frames.
3 hours ago