Welcome back for another edition of What I Screwed Up This Week! This week, we look at a difficulty with chisels.
While I was paring the hinge knuckles for the Roubo bookstand I built back in February , I ran into trouble keeping a 45 degree angle consistently for each knuckle. The edge angles were easy since I had a marked line on the side of the board to follow. However, I lost this reference on the inside knuckles.
I took my sliding bevel, set it to 45 degrees, and then used it as a guide to help me line up my cuts. This was better, but still allowed for variable results. I was still freehanding, and the gap between the chisel and the bevel necessitated by my hand made this approach assisted eyeballing at best.
I would have gotten better results if I had cut a piece of wood to the 45 degree angle and used it as a guide, at least for the last critical cuts. This is a trick that I once saw Tommy MacDonald use on his old podcast, and I didn’t remember it until after the fact. It solves both problems at once, but is really limited to lighter cuts due to the hand position required. A conbination of the two techniques would probably yield the best results.
Even though they’re called hand tools, don’t be afraid to come up with guides or jigs to help with alignment. The old-timers were smart enough not to work harder than they had to. Once again, this is an area where going back and reading some of the historical texts can give you lots of insight. Oh yes, and don’t forget to keep those chisels sharp. Nobody gets good cuts with a dull blade.