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Information about Hook Tools
Overview
"Hook" tools are a
woodturning tool or tool bit intended primarily for use in the removal of
end-grain stock. It's unique design provides for easily reaching deep
into stock while creating an open or hollow form while typically leaving a
superior, very smooth finish. It can also be an excellent and highly
efficient substitute for a traditional bowl gouge when performing side-grain
turning especially where a traditional shaped bowl gouge becomes unsafe to
use because of depth or other factors. In fact the edge and shape of the
hook tool is essentially a gouge's cutting edge on its side (see picture at
right).
Though the hook tools are an
extremely efficient tool for most end-grain work, in some situations, to
protect your hook tool from damage in extreme conditions and maintaining
good control over the cut being produced, it is suggested you switch to use
of a machinist tool bit tool or a heavier, more stout bent tool. Such is the
case if you expect to encounter hard knots or where you may wish to create
tightly undercut or rolled edges on closed forms, with sharp angles of
departure from the entrance of the vessel where the shape of the tool may
not allow the cutting edge to reach well. However, in the latter case,
different shapes of hook profiles may still accommodate you quite well.
Simply experiment with a few tools to find what their cutting
characteristics are.
How to get one?
Del Stubbs, Mitch Wolok and
Alan Lacer are reported to have helped this tool to emerge and become
popular.
Hook tools can be easily
made from O1 type drill rod in your own workshop for only a few dollars
provided you possess rudimentary metalworking skills. See Alan Lacer's
website for an article on
How to make a hook tool.
 Hook
Tool "tips" or similar tools
can be purchased from vendors like Mitch Wolok who offers a hook made of
M-2 high speed steel (Rc 62-64) retailing for around $25, or
Termite
Corporation which has a fully closed "ring" type tool which retails for $100
with handle and sharpening kit (see picture). Termite tools are sold by many suppliers like Craft Supply,
Woodcraft, Rockler, Etc.
Directions for Usage:
-
Drill a centering hole to
final depth as true and centered as possible. If the hole is drilled off
center, the Hook Tool will tend to bounce off the sides of the turning until
the hole becomes enlarged and true.
-
The tool rest should be
positioned above center.
-
The Tool will cut its best
between the 9:00 and 6:00 O'clock positions.
-
The Hook Tool is about a
one-fourth inch diameter; therefore, limit your cut to one-quarter inch deep
or less. If you try to take a deeper cut, you will run out of cutting edge.
-
Start cutting from the bored
hole straight across by slightly pushing (similar to riding a bevel on a
gauge) against the edge of the tool.
-
When you reach the wall
thickness you desire or when the tool stops sliding towards the side, (in a
vertical position---not riding the bevel), draw the tool toward the front.
When the tool is working at its optimum, it will draw itself towards the
rear.
-
As you get
deeper into the vessel or form, you may have to adjust the tool rest to a
higher position to allow the tool to be presented at an angle where
the cutting edge can contact the interior wall.
-
Use
Caution: The Hook Tool should be presented to the wood surface in a
vertical position (like a tire is on a car) with the bit end of handle
tilted slightly downward. Never try to engage the tip fully rotated to a
horizontal position! You will lose all possibility of the bevel rubbing and
it will become like a knife edge. This is way too aggressive of a cut and
you will find a catch every time.
Additional Suggestions
-
There really
are no rigid rules
on tool position except that it
is not designed to
operate in a
flat, horizontal position with
the cutting edge point up.
-
Try
supporting the end of the tool handle under your armpit. Enter the wood with
the cutting edge vertical so the tools edge won't cut, and then begin
rotating the tool clockwise to engage the edge. Lowering the Hook Tool bit
end will usually help you engage the edge and initiate cutting. In some
troublesome woods you may even wish to raise the bit up above the 9:00
O'clock position by lowering the end of the handle (and rotating the bit)
until a really crisp clean and smooth finish cutting position is found.
-
If the tool
stops cutting and begins scraping, drop the hook down below the 9:00
position. If the trouble persists, make sure the tool is sharp. If sharpness
is not the problem, you may have to change the angle to the right or left.
Sharpening
-
Outside -
Sharpen the bit straight across with a flat stone.
-
Inside -
Sharpen the inside cone shape with a round or conical shaped (best)
stone.
-
Either a hand
held slip-stone or a grinding wheel mounted on a small drill will
suffice quite well depending on how dull the tool is.
-
Once sharp
maintaining the edge with a hone will last for a long time.
Note: The above
information is also relevant when using a tool of your own manufacture such as
those shown how
If you like hook tools, try sticking a
Ball End Mill into a handle for hollowing!
to be made by many well known turners, like Alan Lacer, Mitch Wolok and Dell
Stubbs. |
