AW Extra 12/12/13 – Reshaping the Skew Chisel

Reshaping the Skew Chisel

An alternate shape
minimizes dig-ins.

By Alan Lacer

Years ago, an old professional spindle turner
showed me a different way to sharpen
a skew. When I tried it, I was sold. This
modified grind is more versatile, friendlier and
more responsive than a traditional grind. Used
correctly, a modified skew is difficult to catch and
dig into the wood, unlike a conventional skew. In
the years since, I’ve found that many early 20th century
turners from Maine to Indiana adopted
the same alternate shape. They were all on to
something good.

It’s easy to learn how to sharpen a modified
skew. I’ll show you how to take a regular skew chisel
with a flat cross section and turn it into a far
superior tool in an hour or so.

 

Shape the sides

Begin modifying a conventional skew by reshaping its
sides (Photo 1). I prefer to do this on a belt sander
mounted in a stand and equipped with a belt designed to
cut metal (see Sources, below). Be sure to remove all
the dust from the sander and set aside its bag to avoid
starting a fire. Start with a 60-grit belt; finish with a 120-
grit belt. I round the short point side to glide with a
smooth motion when planing and to easily rotate and
pivot the tool when rolling beads.

Grind the tool’s profile on a 36- or 46-grit wheel (see
“The Modified Profile,” and Photo 2, right). I use a
coarse wheel because this step removes a lot of material.

 

Sharpen the edge

Switch to a 60- or 80-grit wheel. Adjust the tool rest to
grind the same angle as on a conventional skew.
I prefer to set this angle by measuring distances.
The length of the bevel should be approximately
1-1/2 times the tool’s thickness. The angle between both
bevels will then be 35 to 40 degrees. As you grind, you’ll
probably have to tweak the tool rest’s angle to
get it right.

 

Two Tools in One

With both straight and curved sections, a modified skew is
quite versatile.

The curved area is great for these tasks:

– Planing and rolling cuts. If you lead with the short point
side and cut with the tool’s curved section, you cannot dig
in. Digging in is a real problem with a conventional skew
and a bane to all novice turners.

– Planing chip-prone woods, such as red oak or figured maple.

– Forming the concave and convex sections of a spindle.

The straight section is great for these tasks:

– Peeling away wood, like a large parting tool.

– Slicing rounded pommels (with the long point down).

– Scraping end grain and knots.

– Working in tight areas. The curve creates a small clearance.

 

Begin sharpening the straight section (Photo 3). Flip
the tool as you go to remove the same amount of material
from each side (Photo 4).

Now for the curved section. You’ll grind and sharpen
this in one long sweeping motion, using your fingers
as a pivot point (Photo 5). Start next to the
straight section, then rotate the long point off of the
wheel. Continue in one fluid motion down to the short
point. Stop when the area around the short point is
square to the wheel (Photo 6). Then, without changing
your hand position, rotate the tool in the opposite
direction, back toward the straight section. The idea is
to fan the tool back and forth without lifting it from the
tool rest. Make three or four passes on one side of the
tool. Then flip the tool and make an equal number of
passes on the other side. Continue sharpening and flipping
until the bevels meet at the cutting edge.

As with any turning tool, you’ll know when to stop
sharpening by watching the sparks. When they fly off
evenly both above and below the bevel, the cutting edge
is sharp. To confirm that it’s sharp, lift the tool and look
down at the edge under a bright light. A dull area
reflects light; a sharp edge disappears into a black line.

 

Hone and test the edge

I’m a big believer in honing. An extra-sharp skew is
safer and performs better. I use a diamond slipstone on
high-speed steel tools because it cuts fast (see Sources,
below). To get the angle right, hold the slipstone so it
only rubs on the bevel’s heel (Photo 7). As you move
the slipstone up and down, incline it until it touches
the cutting edge as well; then maintain this two-point
contact. Repeat on the other side. Hone the tool’s sides
near the short and long points, too. Test your tool by
making a light planing cut (Photo 8).

Click any image to view a larger version.

The Modified Profile.
My skew’s profile has two sections: straight and curved.
The straight section begins at the skew’s long point and
extends one-fourth to one-third of the blade’s width. The
curved section continues to the skew’s short point. The
angle from long point to short point is about 70 degrees,
the same as on a conventional skew.

I also modify my skew’s body. I round over the short
point side and lightly chamfer both edges of the long
point side.

1. Begin modifying
a standard
skew on a belt
sander. Hold the
tool so the belt
always travels
away from you.
Completely round
the short point
side up to the ferrule;
chamfer the
sharp edges of the
long point side.

2. Grind the
straight and
curved profiles.

Position the tool
rest about
90 degrees to the
wheel. I’ve mounted
a wood platform
on my tool
rest to have a
broader area of
support, which is
critical for modifying
and resharpening
a skew.

3. Begin grinding
the profile’s
straight section.
Color the
old bevel with a
felt-tip marker to
identify where
the wheel cuts.

4. Flip the tool
now and then
as you continue
grinding. It’s
important to keep
the bevels on both
sides of the tool
equally long to
center the cutting
edge.

5. Grind the
curved section

by using
your fingers as a
pivot point. Keep
the spot you’re
grinding square
to the wheel.

6. Continue
grinding
with
a fanning motion.
When you reach
the short point, as
shown here,
reverse the direction
without lifting
the skew from the
tool rest.

7. Hone the cutting
edge

with a diamond
slipstone. It’s
easy to find the
correct angle by
feel. Hold the
slipstone so it
contacts two
points on the
bevel’s concave
surface: the heel
and the cutting
edge.

8. Check the
tool’s sharpness

by putting it
to work. Make a
planing cut on a
cylinder. A sharp
tool will require little
effort to push,
produce lots of
shavings and
leave a very
smooth surface.

Sources

Note: Product availability and prices are subject to change.

Alan Lacer, alanlacer.com, 715-426-9451, Diamond
slipstone plated on two flat sides and two round sides.

MSC
Industrial Supply Co.
, mscdirect.com, 800-645-7270, Diamond
whetstone plated on one flat side only, #01054931; Sanding belts
for metal, Norzon, Three-M-Ite or MetaLite brands, many sizes and
grits available.

This story originally appeared in American Woodworker March 2007, issue #127.



March 2007, issue #127


Purchase this back issue.