No, not the name of my Goth band.
A while back, in trying to bore some straight holes, I’d set up some squares to use as reference. As I went along I realised I wasn’t watching the brace in relation to the squares, but the shadow of the brace along the wood in relation to the shadows from the squares. Since getting squares to sit still while boring can be a pain, I just started marking the shadow lines and using those as my points of reference.
Having a goose neck lamp that is adjustable helps a lot.
This week I chopped two miserable mortises before remembering that trick. I’d used a jig to register against the side of the chisel, but that was distracting to me. And I wasn’t able to chop straight, anyway.
Using guide lines drawn off a square’s shadow allowed me to chop mortises with straight walls. The process was pretty easy. Mark out the mortise, set up a square along one end and draw a pencil line along it’s shadow. Advance a bit, repeat. As I chopped I would set the chisel to what I thought was perpendicular to the surface, check against the line, and correct.
While this may be veering off into unnecessarily complicated territory, I found that after a few chops my sense of holding the chisel straight improved a bunch. I used the lines as reference less.
I could have stuck with the jig, but I feel like (s0me) jigs are like training wheels. Sooner or later I’ll want to kick them off. Using the shadows helped me move from training wheels a bit faster.