Re: Mortise question for Adam C.
Adam Cherubini, NJ
>You mention cross-grain paring followed by removing triangular chunks. I'm imagining holding the chisel diagonal to the workpiece
No. You're just making a series of incisions, if you will, perdendicular to the length of the mortise, perpendicular to the mortise's cheeks, parallel to the ends you chopped in the previously step. Okay? Not diagonal.
It really is hard for me to explain and frustrating. You may not prefer this tecnhique, you may think I'm wrong (and I may be), but in 3 minutes you'd totally understand why I do it, why the chisel is shaped the way it is, why I hold it the way I do, why 19th century mortise chisels are still in such great shape, etc.
Anyway, these incisions are just that. The first pass doesn't produce chips. I like to start at the far end and work backwards towards myself. With each subsequent incision, I align one edge of the chisel with the single gauged line. The incision lifts, but does not remove a thin chip. If the incisions were very close together, you might pop some out. The point is to stay in control, an produce a mortise exactly as wide asteh chisel all along is length and depth.
sidebar
I don't like mortising gauges since the chisel defines the width, not some gauged line. I think mortising gauges should be called tenoning gauges for their use makes more sense there.
On the second pass, working from the opposite direction, similar incisions make little vee shaped chips, but they are very thin. I continue with these light cuts back and forth until my mortise is deep enough to guide my chisel 1/4-3/8" deep. Keeping the mortise straight and true after that (when I start working faster, cutting more aggressively) becomes a function of keeping as much chisel in the mortise as possible. That happens by keeping a low angle.
I may be totally wrong about all this, but I see this same technique used when sawing. To correct a cut, you lay the saw down into the slit to guide the saw. As in sawing, if the tool is 90 degrees to the work, its length or straightness does nothing to keep your line straight. Like ripping with a scroll saw. Make sense?
Again, I could be wrong, but I see over-arching attitudes or approaches to solving problems in the period shop. Guiding a cut by laying a tool into its cut is one philosophy (for lack of a better term) we see again and again. This technique uses that philosophy, so its seems to "fit" even though there isn't smoking gun evidence for it. The design of the chisel, its handle, the condition of antiques, all seem to corroborate.
Anyway, I hope I answered your question. If not contact me off line, so we don't bore everybody with this topic.
Adam
P.S. I find the stuff about the over-arching attitudes really interesting. Anybody else? That's sort of what my talk was about to the CJWA. I think there's another level or two of woodworking beyond techniques. I also think the period techniques are all related, physically, philosophically, etc. When you stumble across them, you get that Ah Ha! sort of moment, like a new discovery. Anybody else?