>I thought it was only the TO that had to be right or left
>handed. The last one I ordered for the left hand on was sent to
>me with both sides beveled. I didn't think that was correct but
>used it anyway. Actually it seems Ok, but am I working under an
>additional handicap?
I can't seem to get a long "o" (an o with a line over it) into my
email, so I'll use the spelling "toh" as the name of the tool we're
discussing...
A right handed toh is beveled on the right side of the blade, and a
left handed toh is beveled on left side (as you look at the blade in
front of you, point down, cutting toward you)...
The toh is a much more refined and high-tech tool than you might
imagine at first glance! A good-quality toh is not just a piece of
bar-stock with a skewed bevel cut away on one end! First, unlike
Western tools, the blade is made of not one, but TWO layers of steel
-- a thinner layer of harder (and more brittle) steel on the side
where the edge will be made (this side is dead-flat and polished in
order to produce an effective cutting edge). The other side is a
thicker layer of softer (less brittle / more ductile) steel -- that's
the side which will be ground away to produce the edge -- it supports
the hard blade and helps prevent it from snapping during use, and
because it's softer, it allows you to keep your tool sharp with less
time and effort.
These two sides of a good toh are NOT parallel! The blade stock is
thicker on the end where the point of the tool will be! Here's a
crude drawing of the end-view of the blade of a good toh -- the
cutting edge is the vertical line on the left side of the blade and
the point is the upper left corner -- if the tool is pointing toward
us, it's a left-handed toh (and if it's pointing away from us, it's a
right-handed toh:
point _____
| /
hard | / soft
side | / side
|_/
The toh is designed to be used (for accurate carving) with the hard
(edge) side angled down facing the surface of the block and the soft
(beveled) side facing up and visible to the carver. Of course, the
block doesn't 'know' or care whether the blade is beveled on the
right, left, or both sides (so long as the edge-angle is the
same). During carving the wood is equally compressed on both sides
of the blade so the path the tool follows is half-way between the
angle of the two sides.
If the blade were rectangular in cross section, the side visible to
the carver would always appear to be angling into the cut -- but the
sides of the blade are NOT parallel -- their angle has been designed
to be about 12 degrees or 1/2 the angle of the bevel in order to make
the top side of the blade appear to be exactly parallel to the
direction of the cut! Is that COOL or WHAT!!! GREAT idea, whoever
figured that out 150 years ago or more! This ingenious blade
geometry makes it easy and intuitive for the person holding the tool
to accurately follow the design being carved whenever the tool is
held as intended -- with the flat/hard/edge side angled down facing
the block! In practice, I make precise cuts with a left-handed toh
(I'm mostly a leftie for small-motor skills, but a rightie for other
stuff) with the flat (edge) side of the blade angled down facing the
block exactly against the line to be carved, and then I relieve
(clear) most cuts without turning the block with the flat/hard/edge
side of the blade facing up (and the upside-down tool then 'looks
like' it would steer right into the cut to be relieved, but of
course, it doesn't)...
I don't believe there's any right or left handed U-gouge, V-gouge, or
flat chisel, Carol, and I've never seen a toh beveled on both sides--
that sounds like a Western skew-chisel to me (or would it be called
an 'ambidextrous' Japanese toh :))? If it's a Japanese laminated
steel tool, intended to be sharpened as you describe, then it would
have been made quite differently than any traditional toh, as the
hard layer would need to be in the center of the blade with softer
steel on both outside faces -- never heard of such a thing, but
apparently it may exist, as you seem to own one!
May I ask, where you purchased your double-beveled toh, and how was
it described to you?
-- Mike
Mike Lyon
Kansas City, Missouri
http://mlyon.com