NOT TRY INTARSIAS"
original Indian portrait by Al and Myrl Cook, again shows imaginative use
of material, perfectly fit individual pieces, and true understanding of
you are ready to cut your pattern parts. The Cooks use a special trim saw
with a 6 inch blade only 25 thousandths in thickness. They say it is accurate
for cutting smoothly and close to the exact line. (I had such a saw years
ago, but my husband complained I was too hard on the blades. These have
since been improved.) Cooks blade is a sintered Norton. They also have a
ten inch trimsaw.
will guess the next step, which is to wash each oily piece of newly cut
stones in warm water and detergent. Grinding is the next process. Al and
Myrl recommend a 1 ½" x 8" wheel of 220 grit. Keep it wet
and keep it true. The edges of the wheel should be kept sharp. Use a tool
rest to lay your slab on when grinding. Hold it at a perfect right angle
to the wheel with the rest as close as possible to the surface of the wheel.
Grind down accurately to each part of your line.
a piece is ground you are ready to cement it to the correct and exact position
on the plywood backing. For this epoxy is most satisfactory. Use sufficient
adhesive so that it will ooze out from all the edges and push up to fill
the joints, leaving a slight epoxy bead on the surface where pieces meet.
Don't worry about this beading as it will be removed in the lapping operation.
Put a 100-watt light bulb in a flexible necked lamp and position the bulb
over the newly cemented are for a period of at least 30 minutes, but not
much longer. The heat from the bulb, if it is within an inch of the surface
of the slab, will cure the epoxy sufficiently that the slab will not move
when you put the next one in place. Before placing the next piece, see that
background and exposed edges are clean. The cement from the next piece will
form the beading where the two edges are joined, and extra cement on both
of the edges to be joined would be too much.
you work you may need to do some minor regrinding in spots, as each piece
must fit the next one just exactly in every direction and must cover the
designated section of the board. Mr. Cook says to cement in several pieces,
but leave several open sections around them to be certain of the tightest
final fit. When all the pieces are in place there should be no unevenness
and no cracks between the pieces.
grinding (lapping) is next. Cooks lap their work face up with an overhead
lap on a moveable elbow which Al rigged up. They start the process of grinding
and smoothing the surface with 120 grit silicon carbide with a small amount
of water. Not too much, as you don't want to wash the grits of the stone
top. Every 10 or 15 minutes use a damp sponge and wipe off worn out grits.
When the grits are not cutting anymore, you will not hear a sound of friction.
After being satisfied that the surface is as flat and smooth as you can
get it, wash the intarsia and the lap thoroughly.
the grinding process with 220, 400, and 600 grit silicon carbide. Cooks
find that for an 11 inch by 14 inch intarsia, the average grinding time
will be 3 hours for all the grits, except the first which may take quite
a little longer.
600 grit will begin to bring a smooth shine to your work. Check to see that
there are no more scratches. If you have guarded scrupulously against contamination
of grits your surface should be flawless at this time. Then you are ready
for polish. Several polishing compounds are satisfactory, and your choice
depends partially on personal preference, and partly on the type of gem
material predominant in your picture. If your material is all near 7 in
hardness try cerium oxide mixed with a little Linde A with a felt buff and
sufficient water for a creamy consistency. The buffing will take you about
3½ hours on an 11" by 14" piece. When the buffing is completed
the entire surface should have a uniform mirror-like polish.
people like to frame their intarsias. Others make a stone border around
the edge of the picture as part of the intarsia. If you find a frame desirable,
it should be simple and fairly heavy, and custom made for your individual
picture. The color should either blend or contrast, but should not be bright
enough or bold enough to detract from the intarsia.
. . . . . . .
An original western scene by the
Cooks uses various agates and jaspers to depict topographical features.
Notice the clever use of brecciated jasper for the leafy tree bough, and
the petrified wood fence with the highlights and knots placed just right.
Cooks' intarsia jewelry is unique.
These pieces are backed with silver and are only 1/16 of an inch thick.
All pieces are usable as bolas or pins.
the petrified wood tabletop, the scene and Indian portraits the cooks make
clever intarsia "cabochons" for jewelry. These carefully made
miniature masterpieces are cemented to sterling silver background. For jewelry
intarsias, cut the slabs only 1/16 inch thick, in order to keep the finished
jewelry from being too heavy. The silver need not be heavy either, as the
stone cemented to the silver will make the entire piece rigid. The pin back
or bola slide should be soldered to the silver backing before cementing
each piece of stone to the silver, just as you did to the plywood, in the
larger piece. Other processes are the same, except that you will also have
to finish the edges of the jewelry shapes.
forms which are distinct and call for sharp outlines, readily distinguishable,
plus vivid colors, are most adaptable to the jewelry sized intarsias. These
can be plants, animals, birds, fish, individual flowers, fruits, or anything
you like and have the proper material for. Or you could use geometric patterns,
designs based on archeology or astronomy, or simple figures such as ballerinas,
clowns, or masks.
selection of material is of primary importance in a successful intarsia,
and the cleverest use of material in the Cooks' Indian Chief illustrated
this point. The "soft" feathers at the base of the eagle feathers
are made form exactly oriented carefully selected pieces of plume agate.
Each precisely shaped feather of solid agate looks soft and fluffy and ready
to blow in the slightest breeze, exactly like the feathers used in a genuine
all the many types of richly colored jasper in the Northwest, Cooks had
an excellent selection of material for the hands and face. For each feature
had to be subtly blended colors available both lighter and darker than the
basic hue to give highlights and shadows so necessary for realistic portraits.
stones used in the headdress are marble, rhyolite, petrified palm fibers
and turquoise. The shirt is of yellow jasper, with marble and petrified
myrtlewood. Beadwork is indicated by red palm, blue quartz and white marble
and agate. Made of traditional catlinite, the peace pipe which the Chief
is holding is a light with a piece of fire opal. The background is marble
in neutral and pastel tones.
have professional gallery type lights above each of their intarsias. Their
work was featured at Portland, Oregon at a Northwest Federation Show as
well as at the National show in Seattle. They have several projects in mind
and new ideas they wish to work out. Working together to create gemstone
masterpieces is something they both enjoy. Al and Myrl are modest about
their successes, and strike me as typical all-round gem hobbyists, the kind
of people who have made this hobby so successful in America. In mastering
the art of intarsia they have given other hobbyists new goals, fine standards
of workmanship, and have advanced a craft which may prove to be American
lapidaries' most unique art form.