Bowl Gouge Sharpening
Do it by hand,
just like you turn.
By Alan Lacer
How do you make a
velvety smooth bowl with evenly
thick walls and crisp details? Well,
it’s not done by sanding the heck out of it. The
secret is to use a bowl gouge that is properly shaped
and very sharp.
Most bowl gouges aren’t ready to do this kind of
fine work right out of the package. They must be
shaped, sharpened and honed. Shaping a bowl
gouge means altering its profile, also called its
grind. Sharpening maintains the profile and
renews a dull edge. Honing further sharpens the
edge. I’ll cover how to do all three operations freehand style.
I prefer sharpening
freehand, as opposed to using a jig,
because it’s similar to turning a bowl. When you
sharpen, the tool sits on a rest and meets a round
object—in this case, the grinding wheel. You rub the
bevel on the round object and manipulate the edge.
That’s what turning is all about, too. Once you’ve
learned to sharpen freehand, you’re all set to make
a fantastic bowl.
How to Sharpen 3 Profiles
Woodturners shape their bowl gouges into three
basic groups of profiles: traditional, fingernail
and swept-back. Any gouge can be modified
on the grinder to match these profiles. Your choice of profile
depends on your skill level and preference.
I use a coarse wheel for shaping a bowl gouge and a
finer one for sharpening (see “Equipment,” below).
The basic procedures for shaping and sharpening are the
same. After you shape the profile, you grind a bevel to follow
Most bowl gouges are made from high-speed steel (HSS).
If your HSS gouge turns blue as you grind, don’t worry. This
change won’t soften the steel. If the tool becomes too hot to
hold, don’t quench it in water. Let it cool in the air or lay it
on a metal surface to dissipate the heat.
When you’re sharpening a gouge, it’s important to
grind the entire bevel, rather than just the edge. To find
the correct position, contact the heel of the bevel first,
and then raise the tool’s handle until the entire bevel
contacts the grinding wheel.
1. Traditional Profile
The traditional profile is the easiest to sharpen. It’s
created by rotating the tool. To begin, set the tool
rest to create a 45- to 60-degree bevel. Lay the tool
on the rest, positioned to start at one side (Step 1). Slowly
push the gouge toward the wheel. When you contact the
wheel, rotate the gouge until you reach the other side,
and then reverse direction. As you grind, hold the gouge
firmly on the rest and keep its end square to the wheel.
The traditional profile works well in general but has
some limitations. It’s good for shaping the outside of a
bowl that’s mounted with its opening facing the headstock.
But if the bowl is mounted the other way, facing the
tailstock, this profile doesn’t work as well. The traditional
profile is good for opening up most of a bowl’s interior,
but not too good at the transition from the sides to the
bottom unless the tool is ground with a very steep angle.
This profile doesn’t have drawn-back sides, so it’s more
difficult to make the fine finishing cuts that are possible
with the fingernail and swept-back profiles.
Click any image to view a larger version.
The end of a traditional
profile is straight
The cutting edge is
Step 1. Shaping and
is very easy.
Simply start at
one side and
rotate the tool on
the grinder’s tool
rest. Stop grinding
flow evenly over
the cutting edge.
These sparks indicate
the edge is
Step 2. Use a protractor
to check the
angle of your
Sources, below). There is no
perfect angle for
all situations. To
start, 45 to 60
degrees is fine.
you’ll see how
affect a tool’s
2. Fingernail Profile
Grinding the fingernail profile requires more
dexterity than making the traditional profile,
but it’s not difficult. In fact, the operation is
very similar to a few cuts in bowl turning itself.
To begin, set the tool rest about 120 degrees to the
wheel (Step 1). The front edge of the tool rest must be
very close—1/8 in. or less—to the wheel, so you can’t
pinch your fingers in the gap. Rest the gouge on top of
two fingers and push it slowly toward the wheel. Contact
the middle section of the bevel first. Then raise the
gouge’s handle until the full bevel touches the wheel.
Begin a slow upward twist, continuing until the tool is
heeled over on its side (Steps 2 and 3). Repeat this
process on one side of the gouge until sparks come over
the edge and travel down inside the flute—that’s the sign
the edge is done. Do the same procedure on the other
side of the tool and then work on the middle of the gouge
to make a uniform, continuous bevel.
The fingernail profile is the best shape for a beginning
bowl turner. It’s more versatile than the traditional profile.
It works well whether the bowl is mounted toward the
headstock or tailstock and is useful for detailing work on
a rim or foot. The sides can be used for shear cutting and
shear scraping finishing cuts.
The end of a fingernail
profile should be oval, but
not too pointy.
The line from the point to
the top should be straight
or slightly convex, never
Step 1. Sharpen the fingernail
a fluid motion,
one side of the
bevel at a time.
Begin at the center.
the tool and push
it up the grinding
wheel, all in one
shot, using your
fingers for support.
Step 2. Twist the gouge
and push it higher
on the grinding
Step 3. Stop twisting
when the tool is
fully on its side,
at a 90-degree
light passes in
this manner, on
each side, until
sparks just begin
to come over the
3. Swept-Back Profile
The swept-back profile is the most difficult profile
to create, but it doesn’t take a lot of practice to
master. If you have trouble, remember that you
can’t ruin a turning tool by grinding; you only shorten it.
To begin, set the tool rest in the same manner as for a
fingernail profile. The procedure is very similar to making
a fingernail profile, but here you work on the long
sides of the tool first (Step 1). When both sides are done,
grind the front (Step 2). Then blend the front into the
sides (Step 3). Aim for a uniform bevel, but the transition
doesn’t have to be completely smooth. The front and
sides are used in two different turning operations, so the
area in between isn’t critical.
The swept-back profile is also called an Irish, Celtic or
Ellsworth grind. It’s the most versatile profile. Your bowl
gouge can be used as a roughing, scraping and fine finishing
tool. It’s easy to level any surface, inside or out,
when using the gouge in a shear cutting or shear scraping
action. The swept-back profile is not for beginners, however.
It can be too aggressive for inexperienced hands. A
gouge with a swept-back profile also requires considerable
power from the lathe to remove large amounts of
material. Some small lathes don’t have enough horsepower
to handle it.
The swept-back end is
oval or elliptical, but
The sides are ground
back much farther than
a fingernail profile. The
line from the point to
the top should be
straight or slightly convex,
Step 1. Begin making a
by grinding the
sides. Hold the
gouge on its side
and slightly rotate
it to create the
Step 2. Grind the gouge’s
front. Begin with
the center; then
with a small
Step 3. Blend the front
and sides of the
gouge by pushing
the gouge up the
wheel. This technique
to that used to
create the fingernail
Final Step: Honing
I hone all my bowl gouges after sharpening
and routinely touch them up at the first hint
of dullness during turning. Honing isn’t
absolutely necessary, but it has many benefits. A
honed gouge produces a cleaner cut, makes
crisper details and reduces the time I spend sanding.
The more often you hone, the less time you’ll
spend going back to the grinder for sharpening.
HSS gouges are very tough steel. Most slipstones
don’t work well on HSS because they cut
too slow, or not at all. I use a special diamond slipstone
that cuts much faster and fits the radius of
every bowl-turning gouge (see Sources, below).
I hone the bevel first (Step 1). The trick is to
hold the stone flat on a bevel. Straight from the
grinder, this bevel should be slightly concave.
The stone should always contact the ground
bevel at two points: the back or heel, and the area
below the cutting edge, called the toe. I start honing
by only contacting the heel and then angle
the stone to touch both surfaces. Honing the
flute is much easier (Step 2).
Step 1. Using a diamond slipstone to
hone a gouge really improves
its performance. Hone the
ground bevel first by bracing
the gouge and moving the
stone up and down.
Step 2. Hone the inside of the gouge
using the slipstone’s rounded
edges. Brace the gouge against
your side, place the stone flat on
the gouge’s flute and slide the
stone back and forth.
Most turners use a bench grinder to reshape
and sharpen their tools. Just about any equipment
will do, but here’s what I suggest (see
- 8-in. grinder. I prefer a slow-speed model that runs about
1,725 rpm. I haven’t tried them all, but I really like the heavy-duty
Delta 23-275, $175. It has lots of power and feels very stable.
- Rock-solid tool rests. This is the greatest weakness of most
grinders, but not the Delta. Look for supports that have no flex.
They should be easy to angle and move in and out. I added wood
platforms to the Delta’s tool rests to make larger support areas.
- Friable grinding wheels. They come in white, pink, blue or
orange. I prefer a 60 or 80 grit for sharpening and a 46 or coarser
grit for shaping. Look for a J- or K-level hardness for turning tools.
- Diamond wheel dresser. Dressing a wheel is critical for good
sharpening. A dresser cleans, flattens and sharpens the wheel by
exposing fresh grit. I prefer this T-handle dresser ($35, see photo, right) because it works extremely fast.
- Movable lamp. It should be able to illuminate either side of
- A face shield or safety glasses and a dust mask. Be sure to use
these because the grinding dust is a health hazard. Dressing a wheel
creates lots of dust.
Note: Product availability and prices are subject to change.
Delta Machinery, deltamachinery.com, 800-223-7278, 8-in. slow-speed bench grinder, #23-725.
MSC, mscdirect.com, 800-645-7270, 8-in. dia., 60-grit wheel, #86758562; Bushing set, #00390955; 8-in.-dia., 46-grit wheel, #05867163; Bushing set
#00390989; Steel protractor, #06475172.
Packard Woodworks, packardwoodworks.com, 800-683-8876, Diamond Jim grinding wheel
Alan Lacer, Worker of Wood, alanlacer.com, 715-426-9451, Diamond Slipper slipstone.
This story originally appeared in American Woodworker September 2006, issue #123.
September 2006, issue #123
Purchase this back issue.