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Carving a Scallop Shell
Carving a Scallop Shell
by Mack Headley, Jr.
A. Divide height into
9 units (red) and
draw arcs to define
lobes and wing
corners. Divide height
into 5 units (blue),
draw arc to define
hinge and line to
locate outer rays.
C. Sketch in lines to
define convex and
concave rays. Save
for reference. Make
concave rays slightly
narrower than convex
rays.
B. Outline perimeter
with imprint of
gouges shown.
he shell was a very popular detail on English and Colonial
furniture throughout the 18th century. Carved on drawer
fronts, knees of cabriole legs, and the crest and seat rails
of chairs, the shell was appreciated as more than just decoration.
The study of nature was fashionable at the time and artisans at-
tempted to analyze, and capture in their designs, the symmetry
and proportion they found in natural forms. Classicism was also
in vogue, so symbolic meanings (the Greek goddess Aphrodite
arose from the sea on a scallop shell) would have added a di-
mension to its popularity which is hard for us to appreciate to-
day. Yet the shell's appeal as a decorative detail endures.
In this article, I'll go through the step-by-step development of
a shell. This particular shell is a style common on Pennsylvania
furniture. I've chosen to carve an applied shell—one that will be
glued onto a flat surface. You can apply the carving techniques to
carve shells directly on drawer fronts or crest rails.
Carving gouges are made in various widths and curvatures.
The curvature, or sweep, is designated by a number from 1 to 11.
The higher the number, the more pronounced the curve. Curves
are carved by selecting gouges with the appropriate curvature
and transferring their shapes to the wood.
Make a full-size drawing of the shell on paper or wood, follow-
ing the layout shown above. The perimeter is defined by the im-
prints of the gouges shown. These same tools will later be used
to carve the shell. The sweep numbers given correspond to my
gouges. Because sweeps are not standardized, however, you may
find that your gouge doesn't exactly match the curve in the draw-
ing. In that case, choose another gouge to get the right shape.
This shell measures in. high and in. wide, based on pro-
portions of 9 units high by 10 units wide. By using these propor-
tions, you can scale the shell up or down to suit your needs. The
lines between the rays are drawn freehand, pivoting off the
knuckle of the little finger to control the curve. Save the final
drawing as a reference for laying out the rays on the carving.
Mack Headley, Jr. is master cabinetmaker at Colonial Williams-
burg, Va. A videotape of Headley carving the shell in this article
is available from Taunton Press.
Gouge's sweep determines the curves
T
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of the shell on the back side of a in.-
thick board, as shown in the photo at left.
For a beginner, it might be more comfort-
able to start with a paper pattern traced
from your drawing, although I'm inclined
to stay away from paper patterns because
of the bloated character caused by the
thickness of a pencil line. Outline the
perimeter with the gouge imprints shown.
The next step is to saw out the blank on
a bandsaw or with a coping saw. Saw
slightly outside the gouged outline of the
wings and hinge, and around the arc that
defines the limits of the convex rays. It
isn't necessary to saw in and out around
the lobes because it's easier to remove
this material with a gouge.
Lay out the perimeter of the shell on the
back side of the board. Then outline the
perimeter with gouge imprints (left).
right to the line. Angle the gouge so
the bevel is vertical, and cut straight
down in. The force comes from the
forearm and body. Lean into the tool and
push down with your weight, as shown in
the photo at left. Lever out the chip at the
bottom of the cut. These bordering cuts
establish the edge around the bottom of
the shell, as shown in figure 3.
Remove the wood from the concave
rays first. Be careful that the corners of
the gouge don't get under the grain at
points where the outline runs diagonally
across the grain. The danger of tearout is
greatest at the tip of the center ray,
where the cut follows the grain, and least
at the tips of the outer rays, where the
cut is across the grain. Try to keep the
corner of the gouge extended beyond
the limits of the wood as much as possi-
ble, as shown in figure 2.
You can remove the wood at the side
of the wings with little chance of tearout.
If you have a lot of wood to remove or
you are working with especially hard
wood, shear across the grain diagonally
with a skewed cut.
After sawing around the perimeter, cut to the imprint line with the appropriate gouge.
Angle the tool so the bevel is vertical, then lean into the tool and push down with your
weight. Cut down in. and lever out the chip.
1 With dividers, lay out the perimeter
2 Next, with the appropriate gouge, cut
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Define the wings by cutting straight
down with a -in. #5 gouge (top) and
levering out the chip (above).
Sculpt the shell surface by transferring the shape of a -in. #5 gouge to the hinge area
and a in. #3 gouge to the ray area. The #5 cuts (top) follow the grain while the #3
cuts sweep from the center ray down to the wings on each side (above, left and right).
The gouge should lie evenly on the finished surface.
Ride the heel of a -in. #7 gouge on the
shoulder left by the #5 gouge to create a
radius at the bottom of the shoulder.
about 14 in. long, with a piece of cardboard in between. I use hide glue, but any
water-soluble glue will work.
The next step is to sculpt the surface of the shell. The curvature at the hinge area is
formed by a -in. #5 gouge, cutting with the grain as shown in the top photo. When
the #5 gouge lies evenly over the hinge portion, shape the flatter portion of the shell
with a -in. #3 gouge.
With these cuts, your wood will begin to reveal itself. Unless your stuff has very
even grain, you'll have to adjust your cuts to the direction of the grain. Begin the cuts
with the -in. #3 gouge, working from the tip of the central ray out toward the outer
rays at the wings. These cuts, sweeping diagonally across the grain, should work clean-
ly across the most distorted grain patterns. Blend the cuts from the #3 gouge into the
curve from the #5 gouge. The surface is finished when the #3 gouge lies evenly over
the surface of the shell up to the junction of the #5 curve.
Remove most of the extra wood at
the wings with the -in. #5 gouge.
With the tool held vertically, cut straight
down to within in. of the back of the
shell and lever out the chip. Then, ride a
in. #7 gouge along the base of the ver-
tical shoulder that you just cut, working
from the hinge to the tip of the outer ray,
to create a radius at the bottom of that
vertical shoulder. Ride the heel of the
gouge at a low angle against the shoulder
and raise it until it begins to cut. Reduce
the wing surface to a
in. thickness with
a
in. #2 gouge.
4
3 After you've outlined the perimeter, glue the shell, layout facedown, to a board
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Pivot off your knuckle to control curves
when drawing the rays (top). Define the
rays with parting tool cuts (above). Ad-
just spacing by leaning the tool.
draw the rays on the sculpted surface
of the shell. Follow your layout drawing
and practice the technique of pivoting on
your knuckle to control the curves. With a
V-parting tool, make shallow cuts along
these lines to separate the rays, working
from the high center point of the shell to-
ward the edges. This is an opportunity to
read the grain of your wood, and to deter-
mine from which direction final cuts need
to be made. The edge of the V bordering
the concave rays will be saved, as shown
in figure 4. Give special attention to the
cuts that go across the grain diagonally. A
very sharp V-parting tool will make these
cuts with minimal tearout, but if tearout
does occur, come in from the other direc-
tion and clean it up. The area of greatest
difficulty will be at the hinge portion,
where the cuts run straight across the
grain, in. apart. Be careful not to tear
out the wood between these cuts. To pre-
vent tearout at the edge, stop the cut just
short of the edge and complete it from the
other direction. You could also make a
vertical cut with a straight chisel. After the
shallow cuts are made, deepen them to a
strong in. at the rays, tapering to a
strong in. at the hinge. As you deepen
these cuts, this is your last chance to adjust
them sideways for good spacing and flow-
ing curves.
between the parting tool cuts into
convex and concave rays. Because the
rays diminish in width from the tip to the
hinge, several different gouges will be
needed to shape the full length of each
ray, as shown in figure 4. The transition
areas, where the curve produced by one
gouge meets the curve from another, will
need to be blended to get a smooth, flow-
ing line. Strive to produce a finished sur-
face with your tool so there's little, if any,
need to sand.
Begin with the convex rays, starting
about in. from the tip and working out
toward the edge with a -in. #3 gouge. Be
careful not to tear out the edge when
you're cutting across the grain. Cut down
to the bottom of the V left by the parting
tool and ride the side of the gouge
against the shoulder left by the parting
tool cut, as shown in figure 4. If the cor-
ner of the gouge cuts into the facet, you
will ruin your work, so be careful. At its
tip, the ray should show the full curve of
the gouge. Shape the first in. of all the
convex rays with the same tool, then
switch to a
#4 gouge to shape the
5 After the wing areas are completed,
6 The next step is to shape the areas
-in.
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Shape tips of convex rays with a -in. #3
gouge, carefully avoiding tearout on cross-
grain cuts (above). Left band helps con-
trol the tool on concave rays (below).
Cut from the bottom upward with a in. #11 veiner to carve the veins in the wings.
The finished shell is ready to be separated from its backing and glued on a piece of
furniture. The curves and flats are designed to catch and play with light and shadow.
next 1 in. or so of each convex ray. Lastly,
switch to a -in. #6 gouge to shape the
remaining section. Cut in the direction of
the hinge on this last section.
Shaping the concave rays will also re-
quire a series of gouges. Again, be care-
ful when the gouge exits across the grain
and at points where the gouge cuts
against the grain on the diagonal. You
don't need to shape the concave rays at
the hinge area, where they are spaced
only in. apart. The parting tool cut
alone will give the desired visual effect
in the hinge area.
These break up this large, flat surface, and accent the linear quality of the hinge area.
The cuts should run parallel to the side curve of the wing and be spaced about in. apart.
Enter the wood with the veiner perpendicular to the surface to capture the full curve of
the tool as it enters the wood. As with the parting tool, you may want to make a shallow
cut and adjust the spacing by leaning the tool to the side. The veins should be a shallow
in. deep. Dragging the veiner back through the cut burnishes and polishes the surface.
Some areas may need a light sanding with worn 220-grit sandpaper, folded to get into
corners. Be careful not to round off the crispness of sharp corners and ruin the definition
they should give when the finish is applied.
To remove the shell from the backup board, slip a thin knife or palette knife between
the layers of cardboard and gradually work it under the shell until it is free. The excess
paper can be removed by lightly wetting it with water to soften the glue. Your shell is
now ready to be glued in place.
7 The last detail will be to cut the five small veins on the wings with a -in. #11 veiner.
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