"The Art of Intarsia"
by William Grundke

Part Five

A Bit More Of a Challenge
   In the last month's issue, Part Four of this series, we showed you how to make a reasonably simple intarsia. When a project such as that has been completed, the craftsperson should be ready to try something a little more detailed. The intarsia of the red barn pictured on the opposite page is such a project. It offers a greater challenge and the opportunity to learn more advanced techniques which should prepare one to progress into the creation of wide variety of beautiful intarsias.
   To complete this project one must first have a knowledge of the basic techniques of intarsia making which appeared n the first three chapters of this series.
Part One, in the December 1981 issue, covered the selection of a design, transferring the pattern, suitable gem materials, and sawing (including the working of outside and inside curves).
Part Two, January 1982, gave instructions for flat lapping and the various types of grinding involved.
Part Three, February 1982, covered cementing techniques, which included the use of an intarsia press and a cementing jig.
Part Four, March 1982, as previously mentioned, provided the instructions for a beginning project in intarsia making. The techniques covered in the first three parts were used.

   Shown above is the original pattern for the intarsia pictured on the opposite page. Note that the various parts are numbered. Each of these numbered parts designated a different color (and pattern, in most cases) of gem material.
   As can be seen, there are some variations fro the pattern in the finished intarsia. For instance, Parts 5 and 6 in the pattern are for two trees, and Part 7 was supposed to come down on the left side of 6. However, a piece of gem material was found for Part 6 that had a natural design resembling two trees, and it would have been a shame not to make use of what Nature provided. Two other variations are the addition of a bridge and wagon. Putting in the wagon required that Part 14 be enlarged to provide an adequate background. Or someone who has made quite a few intarsias, such variations are no problem. The beginner might find it better to stick to the original pattern.
   If you like this pattern, it can be traced off and used as is. The actual intarsia measures 5" x 8", but the pattern had to be reduced slightly to fit the page. It could be enlarged to original size by drawing squares on it, then copying it into larger squares on another piece of paper. You could add in the wagon, a pattern for which accompanies this article, and the bridge. And, if you are artistically inclined, you might like to make your own variations or even sketch your own picture. If so, be sure to divide it into parts that will be different gemstone areas.
   If you should choose to make your own pattern, learning how this intarsia was done should still be helpful. Several techniques are involved that can be very useful in putting together many different designs.
   Whatever you choose, make a number of photocopies of the pattern, as discuss in Part One. You will need them to provide individual patterns for the various parts of the picture.

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Unit A. . . . . . . . . . . . . . . .. . . . . . .. . . . . . . . . Unit B

   As with just about all intarsias, this one is made up of several units which are assembled, then joined with each other until the picture is completed. There are four units, designated A, B, C, and D. You will find a diagram for each one.
Unit A
   Unit A (see diagram) is the barn, minus the roof, right side and doors, but they are added later). The first operation is to saw some gemstone "boards" for the siding. Select a material of appropriate color; I used jasper in several shades of red.
The "boards" must be cut with absolutely straight, parallel sides. For an intarsia of the size shown, make these strips from 1/8" to 3/16" wide - some narrower, some wider. Bevel the back edges slightly as described in Part Two. (Do this on all the stone pieces for the intarsia.)
   After cutting, the "boards" should be cleaned, then cemented together. For this procedure, use a plywood base with wooden strips on two sides (see Part Three); an intarsia press is not needed. Place a double thickness of wax paper on the plywood.
   The joints between the "boards" should be very visible so that there will be the appearance of actual siding. To accomplish this, the epoxy is colored. The best coloring in this instance is crushed black or brown gemstone. Not only does it add color, bit it provides a filler which separates the "boards" slightly, adding more realism.
   Caution: Be careful in crushing gemstone. Wear safety goggles of other eye protection and gloves. Also avoid methods I which there is the hazard of flying pieces.
   I use an easily made device that eliminates this problem.. A stone is placed in a length (about 6" long) of 1 ½" pipe, the bottom of which rests on a solid surface, such as apiece of steel or iron. A piece of 3/4 " pipe is the other part of the device. It is somewhat longer than the 1 ½" pipe, to provide a handle. Both ends of the 3/4 " pipe were threaded and pipe caps attached. The smaller diameter pipe is inserted in the larger one, then raised and brought down forcefully on the stone, breaking it into fragments.
   Another method is to place gem material in a section of innertube and clamp the ends of the tube shut. Lay the innertube on a sturdy surface, such as an anvil, piece of iron, etc., and strike with a hammer. Reducing the stone fragments to powder could be done in a heavy-duty mortar and pestle.
   Instead of using crushed gem material to color epoxy, you can use polyester resin pigments (see Part Three). However, the divisions between the "boards" will not be as noticeable.
   Put a double thickness of wax paper on the plywood, apply the colored epoxy to the edges of the "boards" and place them on the wax paper, face down. Use the right number of "boards" to provide the desired width for the barn unit. As described in Part Three, butt the joined stones against a wooden strip along one edge of the plywood and hold everything snuggly in place with aluminum push pins (see Fig. 30, Part Four). Put under a heat lamp until the epoxy has hardened. Lap the front surface (see Part Two).
   Adhere the pattern for Unit A to the "board" assembly with Duco cement. Coat the top of the pattern with Duco to make it waterproof. Be sure that the pattern is oriented so that the "boards" are absolutely perpendicular, not running crooked. And, orient the pattern so that there is some excess gem material projecting above and below it.
   Cut out the opening. Avoid undercutting. Break off the stone projections between the cuts with a screwdriver. I use the saw blade and/or Mizzy wheels, separating discs or carving tools. Clean out the corners with separating discs or diamond cut-off wheels (refer to Parts One and Two).
   For the time being, the barn door opening is not filled. Instead, as units are added on, this opening is used as a location in which to place aluminum headed push pins during cementing, helping to accomplish good tight bonds, and to keep the intarsia flat. This aid, and the relatively small size of the intarsia, eliminate the need for using the intarsia press.
   Next, the window openings are made. The first step is to put the unit back under the heat lamp and let it get good and warm. Then note the two lines, designated "X" and "Y", on the diagram for Unit A. Turn the unit face down and cut along these lines with a sharp knife (heating softens the epoxy somewhat, making it possible to cut into it). Separate the side areas away from the rest of the unit by breaking along these cut lines. Cool the unit in water.
   Cut the window openings into the large section of the barn, following the methods described for the door opening. Cut pieces of black stone (or white if preferred) to fit these openings. Cement them in. Re-cement the two pieces removed from the sides.
Following the techniques outlined in Parts One and Two cutting inside curves, saw and grind to the roof line. Leave the excess material on the bottom; it will be cut to net size and shape later.
   A decoration can be made for the bran by drilling a hole at the apex, below the roof line. As described in Part Four, cut a circular piece of appropriately colored stone and cement it into this opening. Lap the face of Unit A.
Unit B
   This unit consists of the roof and the right side of the barn (see diagram). The roof actually consists of some dark red material (jasper was used here) for a shadow and black stone for the roof itself. To begin, scribe the curve of one side of the roof into a piece of red material. Saw and grind to the inside of this curve.
   Grind an end of the black material to an outside curve that matches the inside curve on the red material and cement the two stones together. Saw and grind excess material from the red stone, then grind it to an outside curve (the same curve, all the way through). Keep grinding until the red material had been reduced to a fine line to simulate a shadow (see Diagram B-1).
   Cement the assembly of red and black material into the roof curve on the barn. Saw and grind away excess black material, then grind it to the roof's inside curve, completing that section of the roof. Repeat this procedure for the other side of the roof.
   Another piece of dark red stone is used for the right side of the barn, giving the appearance that this area is in shadow, also. Because this is a small area, it might be best to first cement a larger piece to the barn unit, then cut it to net dimensions.
   The barn unit, except for the doors, is now complete. It is designated as Part 1 in the complete intarsia pattern. Shave off the paper pattern with a razor blade; I use a single-edge blade. Lap the face of the unit.

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Unit C3 . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . Unit D

Unit C
   This unit is composed of the hills behind the barn. Some of the parts touch the boundaries of the intarsia picture. On these, leave extra material beyond what will be the boundary, so that you can trim the intarsia to exact dimensions after it has been assembled. This applies to Unit D, also.
   Start with Piece No. 2 (see Unit C diagram), selecting some gem material that is of an appropriate color for a hill. Adhere the pattern for Part 2, then cut into the bottom, only for the roof line. Leave the bottom material on either side of this area untouched.
   Saw and grind openings for the two trees - Nos. 3 and 4. Tree No. 4 is a juniper, so a piece of dark green gemstone should be cut to fit into this opening. Adhere the pattern for No. 4 to the green material, then saw and grind to shape. Tree No. 3 is a flowering fruit tree; some pink rhodonite or other brightly colored material works well here.
   Cement the trees into their openings. Shave off the patterns and lap the face of this assembly. Fit it to the barn unit and cement them together. Lap.
   Cut and grind the top of Hill No. 2 to line D (see complete intarsia diagram). Following the techniques described before, cut Part 8 (another hill) to shape. Cement it to the growing unit assembly in the location shown in the intarsia diagram. Lap.
   Cut and shape Parts 9, 10 and 11. Cement them into a unit and lap. Then cement that unit to the assembly. Lap again.
   Cut and grind Part No. 12 (the sky) to shape and epoxy it to the assembly. Lap.
The top portion of the intarsia is now complete. From now on, we add to the bottom of the picture. By now you should feel quite confident; you are becoming experienced in this art.
Unit D
   To start this unit, shape and fit Parts 5, 6 and 7. It is best to add these one at a time. Lap after each addition.
   Part 13 is a little different. Cut and grind its top to fit Parts 5, 6 and 7. Leave extra material on the bottom of this piece - about 3". Cement Part 13 to the assembly and lap.
   The next step is to put in the fence. Note in the diagram for Unit D that there is a dotted line marked "C" which goes diagonally from below the fence on the left up to the top of the fence by the barn. Make this cut and set aside the lower portion of Part 13.
   Now, saw and/or grind into Part 13 form the saw cut up to the top of the upper fence rail line. Note that this line is composed of several straight lines (the rails) that meet at slight, but varying angles, giving the effect that the fence is following the contours of the land. Be sure to grind precisely.
   Select some gem material that is suitable for simulating weathered wooden fencing; I used petrified wood. The slab must be wide enough to fit across the entire fence line. Grind the top of this piece to fit exactly into the fence line; do not cut any material from the bottom of the slab. Cement the top of the petrified wood (or other chosen material) to the fence line on Part 13. After the epoxy has hardened, saw and grind the petrified wood to a fine line to make the top rail of the fence. The technique is the same as used for the barn roof. To give perspective, make the rail thinner art the end of the barn. Lap the assembly. Save the remainder of the petrified wood for the bottom rail and posts.
   Now, take the piece you cut from Part 13 and grind its top edge to fit the bottom of the fence rail. Cement in place. Cut and grind the bottom of this piece to the line for the top of the bottom fence rail Lap. You should still have some material fro Part 13. Save it.
   Take the piece of petrified wood and make the bottom rail of the fence following the same procedure as for the top rail. After completing the grinding, lap again.
   Add the last piece form Part 13, fitting it to the lower fence rail. Cut and grind the bottom of this piece to the line for Part 15 (the roadside). Note in the photo of the intarsia that Part 15 and 13 intermingle within the fence, giving a touch of realism. You may choose to do this, or simply bring Part 13 below the fence and grind15 to meet it. Lap after cementing.
   Cut slots for the fence posts. Grind small pieces of petrified wood to fit into these slots. Cement and lap.
   To the right of the bran is another fence. It is done in the same way, cutting up into Part 2.
   Cut and shape Parts 15, 14, 16 and 18. These should be added to the assembly one at a time. Lap after each addition is made. Make a cutout for Part 17 (a bush), grind Part 17 to shape, cement it in and lap. Shape and add Part 19, the foreground. Lap.
   Now trim saw the intarsia to its net dimensions, making sure that the sides meet at true 90 degree angles. To avoid breaking of corners, remember to saw part way through, then turn the picture around and saw in from the other direction. Grind the edges true, also removing any saw marks. Again, to avoid breaking corners, always start grinding at the corners and work back.
   You might wonder if we forgot the bran door. We didn't. We need their opening for pinning through to keep the intarsia flat. As mentioned,, because of the size of this picture, an intarsia pres is not needed as long as we have this opening to help us. (A larger intarsia will require the press.) The barn doors and dark background (representing the interior of the barn) will be shaped and assembled as a unit, then fitted into the opening, much as a gem cutter/jewelry maker does channel work. First, however, we will add:

   For a professional look, let's out an edging of brass around the intarsia. It makes a very effective trim and, at the same time, stabilizes the whole assembly.
   Obtain some brass strips 1/16" thick and 5/16" wide (available at hobby shops). Clean the backs of these strips with a Mizzy wheel. Brass oxidizes rapidly, and if it is oxidized, it will not adhere to the intarsia.
   Cut pieces of the brass strip to the correct lengths for the top, bottom and sides of the intarsia. Allow enough extra to allow for mitering the corners. Miter with a file and check until you have an exact fit.
   Stick a piece of masking tape to the face of the intarsia with part of the tape projecting about 3/8" beyond the edge of the stone. Put a double thickness of wax paper on the plywood cementing board and lay the intarsia on it face down. Place a piece of the mitered brass strip on the tape, against the edge of the intarsia. Lift the tape and press it onto the brass. It will now move back and forth like a hinge.
   With a palette knife, apply epoxy to the edge of the intarsia and to the brass. Lift up the brass strip, with the palette knife, to meet the edge of the stone. Slide the intarsia, pushing it tight against the wooden edge around the plywood. Along the brass edging, drive in finishing nails to hold the metal tight against the stone. Press in some aluminum-headed push pins to assure a snug fit (refer to Fig. 30 in Part Four). Put under the heat lamp.
   After the epoxy has hardened, remove the tape, then scrape away any excess cement with a razor blade. Do a good job here because, in lapping, you will find that epoxy is harder to grind than stone.
   Proceed in like manner for the strips for the other three sides of the intarsia.

   Now, we go back to the barn doors. Take a pencil and paper, and make a rubbing of the opening. Transfer the outline to another piece of paper and draw in the doors and dark area (represents the interior of the barn). Photocopy and cut out the patterns for parts.
   Glue the door patterns to some of the same "Board" material you used for the front of the barn. Cut and shape the doors. Note that they each have a diagonal brace. To add it, saw diagonally across a door piece, adhere a piece of black stone to one of the newly cut surfaces, then saw and grind it down to a thin line, the same as was done for the roof and fence rails. Cement on the other piece of the door. It might work best to do this before cutting the door to net size.
   Cut and shape the "interior" form black stone. Check for fit as you go along.
   Cement the doors and "interior" together, perform any final grinding to make a perfect fit in the opening and cement in place.
   As mentioned previously, there are some variations between the pattern and the intarsia pictured. One such variation is in the doors. You might prefer to follow the intarsia in the photo instead of the pattern.
   Start lapping with 220 grit. (Or, as mentioned in Parts One and Two, depending on the gem material, it may be best to begin with 400 grit.) Proceed through 400 and 600 grits. Be careful when you get to 600 that the intarsia is not pulled from your hands to stick to the lap wheel or fly off. This fine grit mixture makes an adhesion between the stone and lap that can cause "grab."
   I finish with a worn 600 grit sanding belt, working by hand, You will find that this method will help finish spots that you can't seem to get with the lap.
   At this point there is a choice. You can leave the satin finish produced, or you can polish with a favorite buff and compound combination. With such a wide area to polish, be careful not to develop hot spots.

Figure 31

   Note in the intarsia pattern that there are horizontal lines in the upper part of the barn, below the roof peak. If you wish make these, before adding the roof, cut the barn unit at right angles to the "boards". On one cut surface attach a piece of black stone, then cut and grind it to a fine line, and attach the other piece of "board" stone. It's the same procedure as for the roof and fences.
   Instead of making the windows a solid black, you can put I white cross bars. Use the same technique just discussed above. You can make white windows with black cross bars, or even solid white windows.
   Note that there is a fence line along Line D between Part 2 and the parts above, another between Part 7 and Parts 10 and 2, and still another up through Part 2. If you wish to put these in, the method is the same as for the other fences described before.
   Should you wish to add a bridge, the fence technique applies here also.
Another optional addition as mentioned before, is a wagon as shown in the photo. Figure 31 is the pattern. The tongue and spokes on the wheels can be done in the same manner as you would the fence rails.
   Next month we will tell you how to put your intarsia on an attractive background within a picture frame. Other backing methods will also be discussed.


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