Friends,
Wisdom would be wonderful, but I'm happy to settle for opinions and
advice, so no need to hold back.
I have been tidying up my workshop, something I find myself forced to do
once a decade or so by the ongoing growth in my accumulation of pieces
of wood too small to use yet too good to throw away. In doing so I have
uncovered a couple of toothing planes and several toothing blades, all
old, all tapered. Some blades are in good order, (no missing teeth),
others are gapped. The thing which puzzles me is that all seem to have
been sharpened, as though for a common pitch (45 degree) smoothing
plane. This goes for the ones still in the plane as well as the loose
ones, though its difficult to be sure of the original grinding angle as
universally the bevels are well rounded suggesting that previous owners
were careless, or saw no need for care.
I have never seen a toothing plane blade used in a common pitch plane,
and the two bodies I have both pitch the blade at a little less than 90
degrees. The teeth tips are delicate: the gaps are in the run of teeth
rather than at the corners where they might come from dropping the
blade. So why were they all given a shallower bevel?
Since the "depth of cut" when used to scratch the surface of a piece
with such a plane is effectively the depth of the vee between the teeth,
it seems to me to make sense to grind these blades with a steeper bevel
to better support the teeth. A 60 or 70 degree bevel should still
provide adequate clearance behind the teeth. Or would it?
I have no intention of grinding the whole of the bevel to the steeper
angle, that would cost too much of the toothed surface, and based on my
toothing plane use to date I suspect that one re-grind of a couple of
blades will well and truly see me out.
I'll be doing the grinding with a low speed wet wheel device so burning
the tooth tips, which I would worry about if using a dry wheel, isn't an
issue.
What say you all?
Thanks, and Regards,
Tony B
Hobart, Tasmania
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