PO Box 890
Shakudo & Shibuichi
operations. The approximate melting point is 1900°F and the annealing range is 1150 to 1350°F.
The first known use of this alloy was in cast form during the Han Dynasty in China. The development of the alloy was most likely a result of smelting gold bearing copper ores. It was later used by Japanese craftsmen in wrought form mainly for sword furniture. The alloy was frequently used as a base for gold inlay. The purple-black patina makes a very striking background to gold.
Prior to patination Shakudo looks much like plain copper. Dark purple to black oxides can be grown with relative ease. The oxidation solutions can be applied in such a way that silver and high karat gold alloys are not affected. The high contrast produced when this metal is used with other metals can be striking.
When heated Shakudo forms a tough firescale similar to sterling silver. Firescale must be completely removed by abrasive or chemical means prior to patination or the color will appear blotchy.
Baldwin's Patina is specially formulated to color Shakudo. Rub a small amount of the solution on to the alloy with a Q-tip or soft cloth until the desired color is achieved. Stop the action with a water rinse. Other coloring techniques include the application of either traditional Japanese rokusho or simple ammonia. The work can be suspended in a sealed container (plastic bag) with an open vessel of ammonia.
The first known use of these alloys was in cast sculptures during the Han Dynasty in China. A similar alloy was used by preColumbian metalsmiths. The preColumbians depletion plated the alloy to form a silver rich surface that polished to look like silver. The alloy was adopted in Japan for use in sword furniture.
Shibuichi can be patinated to a wide range of grays, olive greens and even sky blue. Pale greens can be produced by alternately swabbing with clear ammonia and rinsing in warm water. A similar green can be produced on the fine silver surface left from reticulation by swabbing with a 50/50 mixture of ammonia and vinegar. The work is then suspended in a closed warm container with a pad soaked in ammonia. Heavy textured greens can be produced by adding salt to the ammonia/vinegar solution. Baldwin's Patina will produce grays and pale olive greens. These colors will also appear after extensive handling.
Note: Patinas may be waxed or sealed to help prolong their life. They will inevitably change with time and usage. The chemical balance of the wearer may also affect the color.
Copyright 2003, Reactive Metals Studio, Inc., PO Box 890, Clarkdale, AZ 86324