Articles from Lapidary Digest

How To Make Channel Work Jewelry

Written especially for Lapidary Digest by

Edwin Elam


Copyright 1998. This document may be copied and used in mineral and gem club newsletters without asking permission, given that the article is reprinted in toto and that cedit is given the author and Lapidary Digest as the source. Others wishing to reprint the article may send a rquest to Lapidary Digest, using the e-mail form on the first page.

The bracelet on the April 1998 Lapidary Journal cover is one of the most unique and beautifully designed and executed pieces of channel work I have ever seen and it well deserves a cover on the Journal. If you haven't seen this and other pieces shown in that issue, I strongly recommend that you search it out. When I asked my good friend and sometime assistant Channel Work Jewelry instructor Hale Sweeny, if he had seen the Channel Work bracelet on the cover of the Journal, he reminded me that I had promised that I would take the instruction sheet that we use in our channel work classes and adapt it for publication in the Lapidary Digest.

I have procrastinated doing this because in our instructions and in our class, we use a number of pictures, examples, and other visual aids in teaching the class. I am unsure of my ability to put these visual aids into words, but I will give it my best effort and hope that the results meets your needs.

Jewelry which has sections divided by flat metal and those sections filled with stone are known as channel work jewelry. This is a type of inlay. Many Zuni and Navaho craftsmen made channel work jewelry. The method that I use and teach depends on some modern materials and processes that were developed by Stanley Tims of Tucson, AZ and others. Any craftsperson who has some experience in silversmithing and lapidary work should be able to do channel work jewelry.
Hale's Channelwork Bola

Channelwork bola by Hale Sweeny
using turquoise, black onyx and
Alabama paint rock agate. Inspired
by Navajo blanket design


TOOLS:

Standard silver tools including:
....a jewelers saw with 2/0 or 3/0 blades,
....a bench pin,
....tweezers,
....mallet,
....small hammer,
....smooth jawed pliers: chain nose, round nose and flat nose,
....side cutters,
....a torch with a fine flame tip and a wide flame tip,
....needle files,
....fine cut flat file,
....soldering pick. This can be made from any hard steel wire with a 2" to 2-1/2" piece of wood dowel for a handle. Drill a hole in the end of the dowel, insert the wire and sharpen the pick. The pick should finish up about 6 " long. I use bicycle spokes for the wire but a readily available suitable wire is clothes hanger wire. Soldering picks made of titanium or alloys are available from suppliers such as Rio Grande.

SUPPLIES:

....soft fire brick, variously described as K-20, #1620, magnesia, or soft refractory brick. I buy these brick in bulk from a distributor who supplies fire brick to reline industrial kilns. They can also be obtained from pottery supply houses. I have been told that you can do channel work on a magnesia block but I have not tried it.

....Steel dress maker pins. Stainless steel are best if you can find them. I use to buy them at Wal-Mart but the pins there now are coated steel, which will work. Avoid brass or coated brass pins! Best lengths are 1-1/8" or 1-1/4".

....Channel wire: I use 24 ga. x 1/8" sterling silver strip wire. (Indian Jewelry Supply stock ST24X18P or Rio Grande, # 100-291.) This wire can also be made by rolling 14 ga. round wire down to 24 ga. and annealing.

Indian Jewelry 1-800-545-6540
Rio Grande 1-800-545-6566

....24 gauge sheet sterling silver,

....appropriate findings for pins, pendants, bolas, etc.

....flux (preferably Handy Flux), easy solder, sparex, polishing buffs, tripoli & rouge etc, alcohol, boric acid, small #3 brush for applying flux, masking tape to cover silver.

....clear 5-minute epoxy, toothpicks, something to mix epoxy on, acetone to clean up.

PROCEDURE

For your first piece, select a simple pattern. My first piece was a rectangle divided in 6 equal squares. Using contrasting colored stones made an effective piece. Some type of geometric design works well for a beginner. Two things to avoid in selecting a pattern are tight inside curves, which are hard to cut in stone, and elements which have a long, thin point; the stone point breaks off.

Also when choosing your pattern, consider the lapidary equipment you will be using to grind this piece when it is finished. If you are grinding on a 1-1/2" wide wheels, one dimension of your piece should be slightly less than 1-1/2 inches. As you gain experience, you will be able to handle larger pieces on the same equipment but start smaller and simpler!

You need a pattern drawn on onion skin or tracing paper plus several copies of the pattern to make your channel work piece. The copies of the onion skin original may be made on a copier, which is also handy for reducing or enlarging a design.

Once you have your pattern on onion skin or tracing paper plus a couple of extra copies, take 4 straight pins and pin your onion skin pattern down to your fire brick, pushing the pins in straight down until the heads are flush with the fire brick. Remember, you are going to form your channel work by pinning the channel wires down on the pattern, forming the wires to match your pattern and pinning them in place perpendicular to your fire brick.

Now is the time to prepare the pins for pinning the channel wire to the brick. Doing this properly will save a lot of grief later on. For a small pattern, prepare about 20 pins by first clipping the heads off the pins. Take your chain nose pliers and bend a hook on the top of the pins. Insert the top of the pin into the jaws of the pliers about 3mm (or 1/4") below the top. The pin should be perpendicular to the jaws of the pliers. Holding the pliers in your dominant hand, use the index finger of the other hand as an anvil to bend the pin up to 90 degrees. Reverse the pliers and bend the hook down a bit more. You should end up with a pin with a hook on top bent at a sharp angle and the hook should be about 50 to 60 degrees in relation to the shaft of the pin. A pin formed this way will hold your channel wire in place firmly and save trouble in the soldering process. The shaft should be straight, up to the point of the sharp bend.

PIN PIN PIN PIN PIN PIN PIN PIN PIN PIN PIN PIN

Select and measure the first wire of your piece. In most cases, this will be the outside wire, which should be, if possible, one continuous strip enclosing the whole design. File the ends of your outside wire square and form it to the pattern by bending with fingers and, if needed, by pliers, checking its shape by continual comparison with the pattern.

Then pin the outside wire in place on the pattern, making sure the joint of the exterior wire is tight. When you have finished pinning up all wires to complete your pattern, you want the wires to be level across the top of the piece so be careful at this stage not to push the wires down into the brick. A general rule is to place pins 3/8" to 1/2" apart. The joints in the wire must be tight but at the same time you do not want your pins too close to the joint. A pin 1/8" or closer to the joint is likely to be soldered to the channel wire.

Bend the remaining wires to the pattern and pin in place. Always cut them a little long and file to fit. ALWAYS file the ends of the wire square. Use your chain nose pliers to push the pins into the brick. This will give you better control than trying to do it with your fingers. As you are forming the channel wire to fit the pattern, strive for smooth curves and straight lines. Little extra bends will detract from the finished piece because it will leave a gap between the silver channel and the stone.


When you have completed the pattern and have the channel wires securely pinned to the brick, check to see that all your joints are tight.

Make up a concentrated solution of boric acid in denatured alcohol. Pour this solution over your piece, just enough to wet the paper of the pattern completely. Set the alcohol on fire. Allow the fire to burn the paper completely. If the fire goes our before the paper is burned, help it a bit with your soldering torch. Two goals here are to get rid of the pattern so it will not interfere with the soldering of the channel wires and to clean the channel wire of any oil from your hands and help prepare it for soldering.

SOLDERING

Methods of soldering the joints in the channel wire vary according to the instructor. Tims teaches a method whereby you flux each joint, place a snippet of solder at each joint, slowly heat the whole piece with the wide-flame torch until the solder melts. I find that the pick soldering method works best for me. All joints are fluxed, using either the brush or toothpicks to apply the flux, and the piece is heated only until the flux liquefies. Place enough snippets of easy solder off to one side on your fire brick for each joint in your piece plus a few extra for those you will drop in the process.

(Snippet of Easy Solder: approximately a 2 x 2 mm piece of sheet solder described as having 65 % silver and melting at 1240 degrees.)

With the fine flame tip on your torch, heat one snippet of solder on the side of your firebrick until it forms a ball. The trick here is that as the solder snippet begins to turn red, slowly move your flame down on the solder. While the solder is still shiny, touch it with the tip of your soldering pick and it will adhere to the pick. Move it to a joint on your channel wire and place it on top of the joint. Heat it again until it turns loose from the pick. Continue to heat the joint, moving the flame in a circular motion until the solder runs. I know this is going to sound like an awkward method to some people who have had some silversmithing experience. It works and it works well. If you have a shaky hand and cannot control a soldering pick, try placing the snippets on one joint at a time and heating each joint separately. My problem with the Tims method is that the wires are different lengths and expand at different rates causing joints to pull apart as you heat the whole thing. Applying heat to only one joint at the time seems to lessen this problem.


When all joints are soldered and the piece cooled, remove all pins with pliers, clean the piece by pickling in Sparex. Pins which have been soldered to a wire may be released by placing and pinning the framework to the brick, upside down, so that the soldered pin is over the edge of the firebrick and sticking up. Then slowly heat the pin and gently push on the shank of the pin with the pick. As soon as the solder loosens, the pin will drop free.

Cut your backing plate from 24 ga. sterling sheet. Place the framework of channel wire on the sheet and mark just outside the outline of the channel wire. Saw out the backing plate. Stamp plate with "Sterling" stamp if desired.

The back of the channel wire must be filed so that it sits perfectly flat on the backing plate. This can be done with a fine flat file or by lapping it on the side of a 220 silicon carbide grinding wheel or on fine sandpaper attached to a flat surface.

Thunderbird bola made in a beginning
channelwork classes at William Holland
by Fred Sias (used with permission)
Bolo made in Elam's class by Fred Sias

SOLDER CHANNEL WIRE FRAME ONTO BACK PLATE

Once again the method described differs from usual silversmithing practice but experience has taught me that this is the best method. This process is based on using Handy flux; other fluxes may work, but this has always worked for me.

Clean the channel wire and back plate by pickling. Coat the back plate all over with flux. Position channel wire on back plate and "stick" in place by gently heating the flux. Place snippets of Easy solder in the pockets of the channel wire. Snippets should be flat on the back plate but must touch the channel wire. Strictly as an estimate, a 2mm snippet of solder for every 1 linear inch of channel wire should suffice. Once again gently heat the flux to "stick" the solder in place.

Use wide flame tip on your torch. Put your piece in the center of your fire brick. You may wish to stick two pins at the back of the piece to keep the framework from slipping. Use your solder pick to lift the front edge of your piece about 1 inch off the fire brick. Direct the flame of the torch under the piece but pointed at the brick. Move the flame in a circular motion, heating the brick under your piece. Watch the solder on your piece. When it begins to flow, drop your piece on to the brick and gently play the flame over the top of your piece until the solder has flowed completely under the edge of all the channel wires

Most students and many experienced silversmiths are amazed the first time this process is demonstrated for them.

Clean your piece in Sparex. Using a jeweler's saw, trim off excess back plate and finish up with needle files and sandpaper. Work carefully so as not to scratch the side of the channel wire in the process. Solder on appropriate finding. Sand out scratches in silver and polish. Cover polished silver with masking tape since you will be handling the piece during the stone fitting operation.

CUTTING STONES

We cut slabs 3 to 4 mm thick for channel work. One of the good things about channel work is that it does not require a lot of stone. A nodule the size of a egg will yield enough material for 2 or 3 average pieces of channel work. The small quantity of stone required permits us to move quickly to higher quality stones such as turquoise, lapis, sugilite etc. If you cannot find slabs the right thickness, you can slab small pieces on a trim saw by hand.

The next job is to cut the stones to exactly fit into the individual silver cells in the frame work. You can use one copy of the paper pattern to cut apart into individual piece patterns. Then glue the individual pattern pieces onto the slabs to mark your stones to size. You may use clear acrylic spray to water proof the pattern. At this point, the actual framework may not be exactly as you had originally planned, due to small variations in making the framework. To get an exact pattern of your actual frame, press the framework into an ink pad and stamp this onto paper to make exact patterns for each element of the channel work, then cut and glue these onto the slabs.

With the stones marked, use a trim saw to cut each stone as close as possible, and then grind to fit in the pocket. Now the process is one of grinding a little and checking fit often. Each stone needs to fit as closely as you can make it. Do not force the stones into the channels. You should be able to lift the stone back out without using force, possibly by using 'duck tape' or other adhesive tape as a 'dop stick'.

When all the stones are fitted, clean the stones and the piece with alcohol and epoxy the stones in place with clear epoxy. If the stones have been carefully cut and fitted, there is no reason you will need more than 5 minutes to epoxy and insert the stone. Thus I suggest you use clear 5-minute epoxy for all blueing. A longer curing time is not needed.

Almost any kind of cabbing outfit will work for the stone work in channel work. The first piece of channel work that I did independently was a "rose pendant" done in red jasper, chrysoprase for the leaves and a petrified palm wood stem. The smallest stone in the flower was about 2 x 3 mm and it was cut "freehand" on an 8" silicon carbide wheel. If you feel it necessary, you can dop your stones. I never dop but admit I lose some fingernail and some skin occasionally! I later discovered a little machine called a "Glastar". This machine has two vertical diamond wheels, one is 3/4" or 1' and the other is 1/4". It was designed for stained glass workers to dress the curves in glass. It is the best machine I have seen for fitting the stones in channel work.

When all the stones are fitted, clean the silver framework and the stones in denatured alcohol. When the stones are dry, epoxy the stones in place with clear epoxy. Your object is to set the stone so that it just a 1/2mm above the top of the channel wire. Thicker means longer grinding but doesn't hurt anything. If the stone does not come up to the top of the channel, your piece may end up thinner than is desirable. I use the flat plastic lids off certain food containers such as ice cream or margarine to make shims to put under the stone where necessary.

GRINDING AND POLISHING THE TOP OF YOUR PIECE

When the epoxy has set, it is time to finish up you piece. Any cabbing outfit or the all purpose flat lapping machines will work for this. Some people think you are going to contaminate a machine with the silver. I have never had a problem with silicon carbide wheels, sand paper, or any of the diamond wheels and I have used all of these, both for channel work and cutting cabs.

On the coarse wheel, the objective is to grind until you have touched all the tops of the channel wire. After that, it is just sanding and polishing as if you were cutting a flat cabochon. A slight doming of the piece may help in the polishing but work carefully. You will have to remove a fine wire of silver turned down by the grinding process around the edge of the piece and you may lightly touch up the polish on the silver.

ALTERNATIVES

For beginners and for those who do not have access to cabbing equipment, I recommend hand lapping your piece using a piece of glass as a lap and grits and polish such as might be found in a rock tumbler kit.

Start with about 1/4 teaspoon of coarse grit in the middle of your glass. Add a few drops of water and place your piece on the grit and begin lapping by moving the piece in a circular pattern. You may have to replenish your grit but keep lapping until you have begun to touch the top of all the channel
wires.

Clean your piece and your glass carefully and go to the medium grit until you have eliminated all scratches made by the coarse grit. Follow a similar process for the fine grit. The lapping action will reduce the size of the grit particles of the fine grit until you begin to obtain a semi-polish on your piece.

A piece of leather or denim cloth stretched over a small block of wood will serve as a polishing lap. Place a small amount of polishing compound on the lap and moisten it. Lap as before until you obtain a satisfactory polish on your piece. I use tin oxide polishing compound but other polishing compounds such as cerium oxide or chrome oxide may work.

Touch up the silver polish and wear with pride!


Edwin Elam
Alabama Mineral and Lapidary Society