Mokume gane and Keum Boo - What are they?


      Mokume Gane began in feudal Japan during the Edo period(1603–1868).  At that time,  swordmaking was a ritual process that resulted in a well balanced, strong and elegant blade that was highly versatile.  This versatility was achieved through heating, hammering and folding layers of high and low carbon steel together in the blade.  Such a superior weapon inspired equally superior decoration of the hilt and guard. Denbei Shoami (1651-1728) is given credit for inventing the mokume process in order to mimic, in metal, the layered and carved lacquer work that had been perfected in 15th century japan. 

The Mokume pattern is achieved by laminating sheets of differently-colored, non ferrous, metals together, reducing their thickness and then patterning them.  In feudal Japan, this was accomplished entirely by forging.  Today, thanks to  the efforts of James Binnion and Steve Midgett, and to advances in technology, there are simpler ways of producing mokume. 

I use an electric kiln to fuse sheets of differently colored metals into a billet that is approximately 1/3 inch thick.  Once fused, the thickness of the billet is reduced by forging and/or rolling.  This process also compresses the layers.  I pattern the sheet by raising bumps on the sheet with punches and then filing them away.  This produces a topographic map-like pattern in the metal.  

It usually takes eight hours to fuse the billet in the kiln and another 4-8 to roll and pattern the sheet.  After that, the sheet may be formed, sawed, sanded and soldered into jewelry.

What is KEUM-BOO?

     The Korean technique of Keum-boo translates to “gold added.”   It is a way to apply  24k gold to fine silver and was used in various Asian cultures to adhere gold to iron, steel and copper. The Korean method is also spelled kum-bu. 

The Keum-boo process involves depletion silvering a flat sterling piece (creating a fine silver layer) by repeated heating, quenching and pickling.  Once the fine silver layer is created, the piece is heated to 650oF, pieces of thin 24K gold foil are emplaced and pressure is applied to make a diffusion bond between the gold and silver.  The keum-boo pieces can then be used in the fabrication of jewelry and may be patinated, polished, or left white.

Please Scroll down to see Examples of this work