Skew Planing

Skew Planing

By Alan Lacer

The skew is one of the most useful tools in the turner’s
arsenal. This article will get you on the right path towards
mastering this tricky but useful tool . A lot of us start out
trying the skew without a clue as to how it is used. The result is
often a nasty dig-in that leads most people to retire their skew to
a drawer someplace. There, the secrets and abilities of the skew
lay dormant and undiscovered. It’s not a surprising phenomenon
because the skew has a steep learning curve with lots of subtlety.
To add to the problem, there’s just not much instruction around on
how to use the skew.

I have been teaching students how to
master the skew for decades. I
always start with skew planing as the
fundamental skew cut. Once you master
this cut, you will be well on your way to
confident use of the tool. I’ll first show
you how to practice the cut. Plan on
working a number of practice pieces
before tackling actual projects. In
future articles we will build on that
foundation and look at other more
advanced skew cuts.

 

Applications

The number one application for the
planing cut is spindle work where the
grain of the wood is parallel to the bed
of the lathe. Planing cuts are used to
create cylinders, tapers and shallow concave
or convex cuts. After practice with
planing cuts, I encourage my students to
make their own tool handles using a
skew (Photo 1). It’s a great first project
to hone your new skew planing skills.

 

The right skew

A wide skew is best for planing cuts
(Photo 2). It’s extremely important that
the skew be very sharp. The degree of
control with this tool is in direct proportion
to the degree of sharpness. Be sure
that the corners behind the cutting
edge are softened or rounded over all
the way back to the ferrule. This allows
the tool to glide on those corners with a
smooth motion across the tool rest.

The modified grind that I favor
(curved edge for the lower two-thirds,
straight across for the upper third) has
one huge advantage for the planing cut:
if you maintain the cut in the curved
section you will almost always avoid a
dig-in. Also, a curved edge cuts cleaner
in woods that tend to chip.

 

Prepare the lathe

The next step is to prepare the lathe
itself. I strongly recommend using a cup
drive rather than the spur center that
came with your lathe (Photo 3). Finally,
check the tool rest and file out any nicks or dents with a mill file. Finish prepping
the tool rest by rubbing on a little paraffin
wax. Now your skew can glide effortlessly
across the rest as it cuts.

 

Practice makes perfect

Start with a 2” x 2” x 8”. square blank
mounted between centers. I suggest a
softer wood like yellow poplar or red
alder that’s straight grained and free of
knots. Cut up 2 x 4’s will do in a pinch.
Just be sure to cut out the knots.

Always wear a full faceshield. With the
lathe set to a moderate speed (900 to
1400 rpm) use a spindle-roughing gouge
to create a cylinder. In time you will enjoy
roughing short pieces like this by planing
with the skew.

Start your practice cuts with the skew at
the right end of the cylinder (Photo 4).
Slowly advance the tool to the left until
you reach the edge of the wood. Turn off
the lathe and admire the quality of the cut
surface. Develop your skill by cutting
both directions on the cylinder (Photo 5).
Also, be sure to always cut “downhill”
(larger to smaller diameters) when there
is a variation in diameter.

 

Typical problems with planing cuts

Dig-ins: This is perhaps the most feared problem
as it does considerable damage to the
wood and to your nerves. A dramatic digin
often causes new turners to reject the
skew as having a mind of its own and a
vicious one at that. As a consequence they
miss out on all the skew has to offer the
serious turner. To avoid dig-ins, use a
large skew and stay within the lower twothirds
of the edge (Photo 6). Even if you
cut with the short point or leading edge
of the skew, it won’t dig-in (Photo 7). A
dig-in always happens when the unsupported
portion of the tool (the long point
or trailing edge) is pulled into the wood
(Photo 8).

Run-backs: Run-back, aka screw threading or spiraling,
is one of the most common problems
students have when learning to plane with the skew (Photo 9). The
cause is simple but subtle: loss of bevel
support below the cutting edge. It can
occur at anytime: when you first contact
the wood, midway in a cut or at the conclusion
of the cut. The solution is to
keep the bevel in contact with the wood
at all times.

Chipping:
Just like using a hand plane or running
a board over a jointer, chipping or
tear-out can be a significant problem
when planing with a skew. Some woods
are naturally more “chippy” –such as
red oak or figured woods. Borrow techniques
from the hand plane user:
change direction and “skew” the skew
chisel by moving it from a 45 degree
angle to the axis of the lathe to 60 or 75
degrees. Anyone who has used a jointer
knows that a slow feed rate reduces
chipping. In highly figured woods I
sometimes advance the tool at a crawl—
but end with little or no chip out.

Ribbing:
When you hear an odd humming
noise and notice the wood has a corrugated
or washboard appearance, you
have encountered “ribbing.” Slight ribbing
is not considered a major flaw and
can be sanded away easily. Deep ribbing
is a major flaw that often happens on
long narrow stock. Usually the cause can
be traced to the tool bouncing in and
out of the cut or the wood flexing. A dull
tool contributes to both causes, so keep
the skew sharp. To steady the flexing
wood, many professionals use a hand on
the backside of the wood (Photo 11). If
you are not comfortable with this
approach, try an overhand grip while
applying downward pressure to the tool
rest (Photo 12). Remember – practice
makes perfect.

This story originally appeared in American Woodworker January 2008, issue #133.

Purchase this back issue.

Click any image to view a larger version.

1. I prefer a
large 1-1/2in.
or 1-in. skew
for
planing. The
modified grind
on the large skew
makes the tool
easier to use.

2. Replace your headstock’s
spur drive
with a cup
drive. A catch is ineviable
when you’re learning. A
cup drive slips like a
clutch to minimize a
catch; a spur drive holds
fast to the wood and
aggravates a catch.

3. Start your practice cuts about 1-in. from the cylinder’s right end.
Cut with the tool’s lower half, or short point, leading the cut. Rest
the skew on one of its rounded corners—not flat on the tool rest. Rub
the bevel on the cylinder, then gently lift the handle until the edge cuts
into the wood without losing contact with the bevel. Slowly advance
the tool to the left.

4. Practice planing in the opposite direction. Reverse your hands or
shift your body around. Experiment with your front hand either
below or on top of the tool.

Typical problems and how to avoid them

Avoid dig-ins

5. A dig-in can
be dramatic
,
especially when
using a spur drive
on dry hardwood.
You’ll get a dig-in
if the unsupported
trailing edge or
long point of the
tool catches and
is pulled down
into the wood.

6. Avoid dig-ins
by using the
lower 2/3 of your
tool, starting just
above the short
point. Stay away
from the red zone
indicated above.

7. The short
point
can
safely enter the
cut because it is
supporteed by the
tool rest. It’s
sometimes used
to cut up to a
detail although it
tends to fray the
fibers a bit.

Eliminate run-back

8. Run-backs are
caused by a
loss of bevel support
below the
cutting edge. The
solution is to feel
the bevel contact
the wood before
the cut is made.
Then, maintain
that feel throughout
the cut.

Minimize chipping

9. Chips are a
serious flaw

that requires major
sanding to fix. To
avoid chipping,
steepen the cutting
angle for more of a
shearing cut and
slow the feed rate.
Also, be sure to
use a sharp tool.

Reduce ribbing

10. Ribbing is
a series of
ridges
caused by
vibrating stock .
To dampen vibration,
support the
stock with your
hand. Set the tool
rest close to the
work and use
your thumb to
press down on
the tool.

11. If you are
uncomfortable
with backing
the wood with
your hand
, try to
keep firm downward
pressure on
the tool. This
helps to eliminate
ribbing from a
bouncing tool.