Mokume-Gane Workshop


by James E. Binnion

Mokume photo courtesy Reactive Metals Studios, Inc.

"Processes, methods, and apparatus presented herein have not been tested or verified by ArtMetal in any way. Anyone using any of this information is doing so at their own risk."

The Mokume-Gane process involves the use of processes that are potentially dangerous to you and your studio. If you are not familiar with or unsure about the proper precautions for the use of the chemicals and processes stated here, then find out about them before trying these processes.

I. Process Outline

A. Metal must be absolutely free of dirt, oxides, and oils. Scrub with wet purple Scotch-Brite & pumice to expose bare metal. Rinse in clean water. Check with the water break test for freedom from dirt and oils, and blow dry or pat dry with clean lint-free paper towel or cloth. It has been my experience that most failures in lamination occur due to improper cleaning and oxide removal. Rinse metal thoroughly in clean running water after acid bath, then dry immediately. I get my best results when I dry the metal with clean dry air from a vacuum cleaner blower that has never been used for anything but this purpose. It is impossible to remove all of the dirt from the blower if it has been used as a vacuum cleaner and this will be deposited on your carefully cleaned metal.

[Torque Plates and stack]

B. Paint the faces of the torque-plates that will come in contact with the laminate with yellow ochre or Scalex and allow to dry. This will prevent the billet laminating to the torque-plates. Stack metal between torque-plates and tighten bolts. Place in vise or hydraulic press, compress stack as much as possible, and then tighten bolts again.

[metal box]

C. To keep out oxygen during the firing of the stack you will make a metal box or bag put the stack in it with some charcoal to reduce any oxygen around the billet. Use strips of thin sheet steel ( >28 ga.) to make a box of the torque-plates. Or make a bag from stainless steel foil tool wrap and place the stack in it see appendix A. Fill the space between the plates with granular charcoal . It is important to pack the charcoal firmly so there is little room for air in the box, and secure edges of box with binding wire as shown. If you use the tool wrap seal the charcoal around the billet by using masking tape to form a box around the perimeter of the plates.

D. Fire the box in a preheated kiln at 50°-100° F below the lowest melting point alloy in the stack (this is where it is important to know the exact temperature in the kiln). Heat soak for 3-12 hours. Copper and gold alloys bond at 1350° - 1800° F; silver and high-silver alloys bond at 1300° -1400° F.

E. Remove stack from kiln. Remove billet from torque-plates and forge while still hot. Use torch to keep billet at forging temperature. Billets with silver must be forged at a black heat (no red glow= max of 900°F), nickel alloys may delaminate if not forged before being allowed to cool.

F. Cool billet and saw off the edges . Remove 1/8"-1/4" from each edge; this reduces the possibility of stress cracking during forging and rolling.

G. Heat billet with torch and continue to forge, a reduction of 50% or more is a good idea. If you have access to a rolling mill that will handle thick material then you can roll at this stage.

H. Start pattern development or roll down until billet is ready for relamination.

I. Develop the pattern with burrs, drills, files , punches, chisels, or mills.

J. Anneal often when rolling down to keep from delaminating billet. Roll until the sheet is at the desired thickness.


Fine Silver 1760  
Sterling Silver 1640  
Gold (24K) 1945 Almost all gold alloys will work. 14K yellow should be fired at 1350°.
Shakudo 1922 95% Cu, %5 Au
Shibuichi 1742 75% Cu, 25% Ag
Kuromi-do 1958 99% Cu, 1% As (This alloy is not safe to make in the studio due to arsenic content.)
Copper 1981 Oxygen-free alloy is best.3
Brass 1749 70% Cu, 30% Zn . Do not place in contact >with silver or high-silver alloys as it will melt (it makes silver solder).
Nu- Gold 1700 A Copper Zinc alloy (Jewelers Bronze)
Nickel silver 2030 65% Cu, 18%Ni, 17%Zn. Anneal often.

Most alloys of copper work well, but unless you know the exact melting point of your alloys, you should run a small test billet to avoid ending up with a molten puddle in the bottom of your kiln. In some cases, one pair of alloys will bond at such a low temperature that the other alloys in the billet will not bond well (copper/silver is a good example: it begins to bond at 1350° and melts at 1450°, while most other alloys like brass or bronze bond to copper at 1500° - 1800°). If this is the case, laminate the high-temperature alloys first, roll that stack out, cut it and relaminate it to lower laminating temperature alloy.

Some thought should be given to the hot and cold working characteristics of the alloys in the stack so that they will match the processes you intend to use on the laminate. Helpful references are melting-point graphs, phase-change diagrams, and working characteristics found in metallurgical texts.

3The Copper Development Assoc. Inc., 405 Lexington Avenue , New York, NY 10017, provides a book of data on over 100 copper alloys. Ask for the Standards Handbook.


The process of Mokume-Gane requires that all of the steps be done in a meticulous fashion to produce the desired results. Forging is one of the most important parts of the process and the one that requires the most skill if the final product is not to delaminate. Most billets should be forged at a red heat (1200° ). Silver and high- silver alloys are the notable exceptions. Silver is "hot short" -- it cracks if subjected to mechanical stress while above 1000°; therefore, it must be forged at "black heat" (900°). If the billet is too hot, the lower melting point alloys may melt when struck or the stack may become so soft that the layers will start to separate. When the billet is too cold during the initial forging, it may also delaminate, so keep a close eye on the temperature of the billet . Try to strike the billet as evenly as possible to cover the whole surface area with even blows and avoid over stressing a particular area. When the billet is at the proper temperature for forging set it on anvil with tongs and begin to forge. The billet will cool rapidly while in contact with the anvil, so you can only strike it a couple of times before it is too cold to forge properly. After forging one side of the billet and reheating, flip it over and forge the other side; this helps to distribute the stress evenly. After the initial forging (working each side 3-4 times), allow the billet to cool and saw off 1/8" to 1/4" of each edge. The uneven edges of the billet as it is stacked form stress points that can cause cracks that can cause delamination during further forging and rolling. The non- laminated areas are visible as dark lines between sheets; cut back until they are no longer visible. Reheat billet and forge until you achieve the desired dimensions.


There are two basic methods of pattern development: One is carving into the surface with burrs, chisels, gravers or mills (round-shaped tools expose the most area of each layer when cutting), then forging the billet or rolling it down to expose the pattern. Try not to cut more than 1/2 the thickness of the billet or you may end up with holes in the sheet during final rolling. The carving and forging/ rolling steps are repeated to develop the pattern. The other method is setting the metal in a medium, like pitch or soft wood, and raising bumps on the surface as in repousse. The resulting bumps are filed off and sanded. Take care that none of the bumps are deeper than 1/2 the thickness of the sheet or a hole will be formed when it is filed down.

[patterns from rotary tools]

When using the cutting or chiseling method of exposing the under layers there are ridges left on the surface of the metal that have a tendency to mushroom over when the billet is run through the rolling mill to smooth the surface. They will end up as thin flakes and or foil that is flush with the surface, they will peel up and leave pits in the surface if they are not removed by the use of sand paper, bead blasting, or file. The best method of locating them is to use the bead blasting as it will cause them to lift up from the surface for removal, a stiff wire brush can also be used to locate them. A good test to see if you have removed all of them is to apply a piece of cellophane tape to the surface and then peel it up. It will lift the foil and flakes up.


All pieces should be thoroughly degreased and all oxides should be removed before any coloring. Tri-Sodium Phosphate(Alkali) in hot water, is a good degreaser. Any coloring solution that works on the component metals is usable. The solution should be tested on a sample piece before coloring the final piece. Try using a slightly weaker solution than normal so that you can control its action more closely. Some solutions will color the laminate a solid continuous color if the piece is left in them too long. The Japanese used a solution called rokusho that colors Shakudo. It is a beautiful purplish-black (the more gold in the Shakudo, the more purple it turns) and turns copper a red brown, Shibuichi a light gray, and has little effect on silver. Rokusho is commercially produced in Japan but not available in the U.S.. The following formula4 is a substitute:

Cupric acetate- 6 grams
Copper sulphate- 1.5 grams
Table salt- 1.5 grams
Distilled water- 1 liter

After thoroughly cleaning the work, it is immersed in the boiling rokusho solution, agitated constantly, and checked periodically for the proper color. A variation on this technique involves applying a paste of ground diakon radish (1 part diakon to 5 parts water ground with a mortar and pestle) to the piece immediately before immersion in the rokusho. The work is agitated constantly, then removed from the solution, and the process is repeated a number of times. The treatment with the diakon is supposed to help in protecting the surface from tarnish and uneven coloring in the initial stages of the coloring process. After coloring, the work should be protected with a thin coating of wax to protect the patina. The waxes used for automobile finishes and floor wax are good for items that will be handled allot, and beeswax is good for sculptural items. The wax is applied with a cloth or brush and allowed to dry and then buffed to a fine luster.

4 The formula and procedure come from ""Research Presentations to the Society of North American Goldsmiths: 1977-1980", Metalsmith Papers Of the Society of North American Goldsmiths "

VI. Torque-Plates

The torque-plates are made from steel that is 1/2" thick. They should be cut large enough to allow for bolt holes to be drilled around the perimeter, and still allow room for the stack in between the bolts. It may be made of mild steel or stainless steel. Thinner (less than 3/4") mild steel will deform in the high temperature of the kiln and it will not apply even pressure after being used once. Torque-plates made from 304 , 310 or 316 stainless steel will last for a longer time without deforming . The bolts should be 1/2" in diameter. If you use thicker plates (1" ) they can be ground flat with a surface or blanchard grinder. This can be expensive unless you have several plates as most grinding businesses have a minimum charge of about $50. New Stainless Steel plates, bolts, and nuts should be placed in a kiln at 1500° for one hour, then allowed to cool slowly. This builds up an oxide coating which will keep them from bonding to each other during firing of the billet.

[Torque Plates with dim.]


"Research Presentations to the Society of North American Goldsmiths: 1977-1980", Metalsmith Papers Of the Society of North American Goldsmiths , Society of North American Goldsmiths, Book Dept. , 513 Everett St. , Wichita, KS 67213

"Jewelry Concepts and Technology" , Oppi Untracht, 1982, Doubleday & Co., Inc., Garden City, NY

"Studio Mokume", William Ard, Metalsmith, Winter 1981

"Mokume Meltdown at Carbondale", Stephen A. Walker, Metalsmith, Spring 1983

"The Complete Metalsmith" Tim McCreight, Davis Publications, Inc. , Worchester, MA.

"The Colouring, Bronzing And Patination Of Metals", Richard Hughes and Michael Rowe, Crafts Council, 11/12 Waterloo Place, London, SW1Y 4AU, England

Supply & Equipment List

I. Equipment

A. An electric kiln with a good temperature control system (accurate to within 50°F)

B. Anvil or other surface to forge on.

C. A 3"-4" vise.( insure the bolts of your torque-plate will not interfere with the jaws being flat against the torque-plate's surface)

D. Torque-Plates and nuts and bolts. (see page six of handout)

E. Rolling mill.

F. 1 lb. or larger forging hammer. H. wrenches for torque-plate bolts. I. Tongs to handle hot torque-plates and billet while forging

II. Supplies

A. Ground charcoal (briquettes crushed with a hammer will do nicely) B. 30ga sheet steel & 22 ga. binding wire for box (hardware store )

C. Stainless steel tool wrap also known as heat treating foil (Machine tool supply house)

D. Purple Scotch-Brite pads (jewelers supply, hardware store)

E. Pumice (jewelers supply, hardware store)

F. Scalex or Yellow ocher (jewelers supply, hardware store)

Appendix A: Stainless Steel Tool Wrap

[Stainless Steel Tool Wrap]

Tool wrap is used by heat treaters to make bags that are air tight to protect air hardening steels from oxidation during heat treatment. It makes an excellent barrier to oxygen during Mokume lamination. To make a bag cut the foil with scissors to be 2" longer than the perimeter of the torque plates ( 4"x4"=16"+2"=18") and about 12"wide. Fold the foil in half along the 18"side and make a double fold at the edges. Use a burnisher or roller to flatten the double fold seam. Make a tube out of the seamed foil and then Double fold the bottom end of the tube to form a bag. Use a rawhide mallet to flatten the bottom double fold. Insert the torque-plates and some charcoal and seal the top of the bag with a double fold. it can now go into the kiln.

James Binnion

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© 1996 All Rights Reserved James E. Binnion / ArtMetal

Author: James E. Binnion
ArtMetal Editor: enrique
Last Updated: 1/19/2012