When it was time to cut mortises in the posts for the sukiya fence project, I cut slowly and carefully. A natural round post left zero room for error. And, it was critical to not ruin a piece of wood that had already had dozens of hours of labor put into it by experienced professional carpenters.
As apprentices, we were being pushed. Traditionally, people of our experience would not be working on a project like this without half a decade or more of experience. Sure, we could manage to do the work, but it was slow. It was not time for practice. It was time to get it right.
Errant thoughts were put out of mind, and I cut. First, I drew a border 2-3mm from the actual mortise ink line, and cut a shallow trench in that to safely receive an auger. Then, from both sides, I cut out the remainder of the small mortise. Using the corner of a high speed steel chisel and a hammer, I roughed out the distance from the small mortise to the actual border, 0.2mm from the actual line.
Then, I cleaned out the waste to 0.1mm, starting by reaching into the corners to define the rectangle. With a fresh wide chisel, I pared to split all lines, connecting the corners. With a small rule, I checked the mortise had no humped sections that would interfere with the tenon.
