Before I pein the shell of the miter, there are a few more things that need to be done. The first is to fit the front and rear infill blocks, which are much simpler to refine to shape before the sole and sidewalls are joined.
I’ve covered most of what I have to offer on shaping the infill blocks in a previous entry, so I’m not going to go into much detail here, other offering a small point regarding the pitch of the infill bed – ideally this should be an exact match for the pitch of the metal ramp it’s going to meet. In practice, though, it is vital to understand the tolerances for ‘exact’ in this application. In short, if the infill bedding angle is even a tiny bid lower than the ramp’s, the plane will work poorly if at all; A slightly higher pitch on the wooden bed, however, is not only acceptable, it’s even advantageous. In this situation, there will be a very slight gap under the blade at the junction of metal and wood, with the blade very solidly seated at the top of the bed and the mouth. This way, when the wedge is set, the blade will be very tightly ‘sprung’ in place, with extremely good registration at the mouth — which is by far the most critical point. I shoot for a very slightly steeper bed than ramp angle – and by slightly, I mean 15-30 minutes (1/4 -1/2 of a degree).
One feature of the Towell plane that I really like is the shape of the front infill escapement. It rises from the plane’s throat in a gentle ogee, which is fairly common, but just below the top there is a single bead which forms a perfect surface for your thumb in use.
Here are the infill sections after sanding (no escaping abrasives in planemaking, unfortunately) and the first coat of french polish.