A Lost Art Form"
by Conrad Grundke
Learning Commesso, Part
I the preparation and assembly techniques for making the "Mountain
Retreat" commesso/intarsia were explained. By applying those tips and
techniques and using the tips on epoxying in this part, we can now begin
construction of the piece itself. A beginner can expect to take a month
to complete this project once the stones have been selected. With experience,
this can be cut down to less than two weeks.
for jewelry "Intarsias," I do not use one of the "Super Glues."
The set-up time is far too short. At least 98% of all of my seams are joined
using a Devcon 5 Minute Epoxy, which allows me to work on the piece within
10-15 minutes. This epoxy is one of the few clear epoxies that does not
yellow when it dries and is strong enough to hold an entire picture together.
When I have several large assemblies to glue together, usually the last
step in completing the picture, I will use a 330 Epoxy. This gives me a
bit more time to get the pieces aligned before the epoxy sets up.
glue two pieces together at a time, if possible. Trying to glue more pieces
simultaneously is difficult and can present problems.
the pieces together face down on two (2) layers of wax paper placed on the
layout board. Being frugal here and using only one piece of wax paper will
result in the front of a beautiful "Commesso/Intarsia" glued to
a layout board.
the past, several methods were used to hide the fit in a seam that was not
quite adequate. Crushing rock in a mortar and pestle from one of the stones
being glued and mixing it with the epoxy was tried. This usually resulted
in a tricolor "Commesso/Intarsia." One color for each of the two
stones and a third for the resulting ground up material. Then a colored
pigment was tried mixing it in with the epoxy to color the epoxy. This introduced
a foreign substance that doesn't agree with the epoxy and the epoxy usually
will not harden and remains rubbery. In addition, unless you are good at
mixing colors you can still end up with a tri colored piece. I strive for
not having seams that need to be aided in this manner. I have used a filler
in my epoxy that has purpose at times. By adding 80 mesh colored enameling
frit to my epoxy I can color my epoxy for seams that I want to bring out,
like the lap between boards in a barn. The frit does not effect the hardening
of the epoxy and, in fact, increases it's strength.
e. I mix
my two-part epoxy on an old extra slab of stone. If I want it to set up
faster than normal, I'll warm the slab under a heat lamp before I mix the
epoxy. My preferred tool for mixing the two parts of the epoxy is an artist
palette knife. This minimizes the generation of air bubbles within the epoxy
and ensures a thorough mixing. Most problems with epoxy results in the epoxy
not getting hard and remaining rubbery. There are a number of reasons for
this; such as moisture, humidity, foreign substances like oil, and inadequate
mixing of the two parts.
two pieces are to be glued I take up some of the epoxy on my finger and
wipe the edges of the two stones to be glued. Then I apply additional epoxy
with the palette knife.
Glue the pieces face down on the layout
board, using steel push pins and a wood fulcrum to hold them in place,
while the epooxy sets up.
the two pieces face down on the wax paper covered layout board, push one
side up against the raised edge moulding in the corner of the board. The
stones should be held down onto the board with steel pushpins. If you need
to apply pressure to force the two stones together, I have used small strips
of wood (similar to a square Chinese chop stick) as fulcrums to apply a
constant pressure against one piece. Pushpins can help to hold the fulcrum
against the stone. See Fig 8.
gluing two pieces together, always lap the front surface flat on a lap wheel.
This will ensure that you do not assemble a whole picture and find some
small section is recessed and you have to lap the entire picture down.
Process: - "Mountain Retreat"
the assembly drawings pieces like 1a & 1b should be assembled as unit
1 before attaching to unit 2.
. . . . . . .
Begin the commesso/imtarsia by making
the church as a separate assembly.
by making the church as a separate assembly using the church assembly sequence,
Fig 6. The tip of the church will be assembled into the sky as a last step
before gluing the sky in place. I then draw the slots and outline of piece
#1 onto the stone selected for the sunny church wall. Cut slot #1a into
piece #1 and fit and insert a piece of mother of pearl or abalone shell
into this slot. Epoxy the window in place.
cut second slot #1b and insert another window. If you try to save time by
cutting both slots in a soft stone it is possible that the piece in between
will break out. These slots can be cut with a "nibbling saw",
described above, a diamond-coated wire in a jewelers saw, or a band saw.
the left and bottom edge of piece # 2 and epoxy pieces #1 & #2 together.
Leave the bottom of piece #1 extend beyond what is needed for the finished
piece. It will be cut off later when fitting the wall, piece #11.
the front surface flat.
#3, #3a, #3b & #3c in a like manner. Fit and epoxy on #3c and then fit
and epoxy assemblies #1-2 & #3 together.
the front surface flat.
church steeple is then assembled. Create the clock with the hour and minute
hand as an assembly #4. Drill a small hole, 1/8" into the sunny steeple
wall material. Enlarge it to the oval shape for the clock. Cut and fit the
clock face into this oval opening and epoxy it in place.
and epoxy parts #5 and #5a together. After this is done cut the top two
arched surfaces to the desired shape. Fit and epoxy #6 and #6a together.
Fit assemblies #5 & #6 together and epoxy. After the epoxy is set up
grind the top of the steeple roof to the desired shape. The steeple is then
ready to be fit and epoxied onto the church body to complete that assembly.
Again, lap the front surface flat.
9. Assembly Process Concluded:
the church building has been completed, the remaining pieces of the picture
can be fitted and epoxied together, one at a time. (See Part I for
the assembly sequence.) When fitting the next sequential section, only cut
the sides of the piece that will be epoxied to the existing assembly. Remember
to lap the front surface after each new piece is added.
you add pieces 10 - 14, do not cut the edge of the picture at this time.
The final outer edge of the picture will be trimmed down once the entire
assembly is completed.
. . . . . . .
you reach sections 17 and 17a, this can be created using two separate stones
fit and epoxied together, or if you can find a stone with the necessary
pattern, this can be created out of one piece. This area of the picture
represents some bushes or trees (17) with some flowers or blossums on the
this picture it is helpful to find a rock that will imitate a rock wall
for section 16. This can be difficult to find. Some stones to consider are
brecciated jasper (as was used in this picture), petrified dinosaur bone,
turetella and petrified palm root, cut at an angle.
21 will be the longest length you will have to fit. This will be a major
challenge, since there will be times when you will grind too much in one
area, affecting the fit in another. I used a thin section of soft marble
for the sky. In the process of fittng 21 into pieces 10 and 12, a piece
of the sky broke off. Normally, I would have cut another piece; however,
this was the only piece of marble I had, and as a means of salvaging the
piece, I inserted a tree between pieces 12 and 10.
piece 21 next to the lower assembly, but do not epoxy. Next cut the slot
for 21a out of 21 and insert the steeple into the sky. Once assembled, 21
and 21a can be epoxied to the lower sections as a single unit. This sequence
will ensure proper alignment between the steeple tip and the steeple roof.
the picture has recieved its final lapping with 220 silicon carbide grit,
the oiuter edges can be marked and trimmed off using a thin-kerf diamond
trim saw blade. I then finish the edges with a 8-inch diamond grinding wheel,
being careful not to let the edge of the wheel cut into the edge of the
picture. Gentle pressure and a slight left-and-right motion across the wheel
surface can effectively trim the edges to their final dimension.