This technique is used to decorate the surface of metal by producing a fine decoration that resembles the grain of wood. It is a traditional Japanese technique, which is used both to create decorative patterns and to give a detailed background on exceptionally fine Japanese metalwork.
The effect is achieved by sandwiching several metals together and then exposing the different colors of the metals on the surface. Up to five sheets of colored metal can be soldered together, and you can use combinations of nickel, silver, copper, brass, monel metal, standard silver, fine silver, and white, red or yellow, gold. The metal sheets should be a similar thickness, approximately 1/48 inch, although because of its cost, the gold can be thinner. The gold will appear only as a fine line in the pattern if the original sheet is extremely thin.
After the sheets are soldered together, they are put through a rolling mill and reduced to a thickness of about 1/32 inch. The metals will need to be annealed during this process. The sheet is then cut into two equal pieces, and one half is placed on top of the other, with the two pieces being soldered together as before. This process of cutting and soldering can be repeated as often as you wish because the number of layers is doubled each time.
After the last soldering to join one half to the other, the piece of metal can be pickled and then rinsed thoroughly and dried. It is then either worked from the back, or indentations are made from the front to create a random or regular pattern. A variety of tools can be used on the front, including different burls on a flexible shaft machine, chisels, and tracer punches, and they can be used to different depths in the metal.
The metal is then passed through the rolling mill until it is completely flat. After this, the sheet is annealed, and at this stage it can be pickled, although ideally it should be boiled out in a solution of soda crystals and water and rinsed.
Using mokume gane
The piece of mokume gane is then ready to be used. You may decide to solder it into or onto another metal, when you should use easy solder, or you could set it into another metal and rivet it. It can be polished in the usual way. To add to the effects of the color, you could, depending on the mixture of metals used, allow the standard silver to oxidize after polishing by applying gentle heat and allowing the piece to cool in the air.
Writer – Jinks Mcgrath