Raku

Kim Peterson

I have played clay for the past 25 years, Raku firing for the past 20, horse hair and slip resist for the past 10 and Feathers for 7.

I have been drawn to Raku for the unique beauty of the pieces. I have a tendency to create individual pieces of art. Each shape may be similar, but seldom will one piece be identical to another. I am not a production potter. 

Raku is a fast, low fire process. The clay is thrown on a wheel and may be altered prior to bisque firing. Now the real fun starts.

Copper Based Glazes: Both my copper matt and copper penny pieces have copper carbonate as the primary colorant. I sometimes add additional chemical to achieve different results. I place the glazed piece in the Raku kiln. The temperature will rise very quickly from room temperature to 1850 degrees. Once heated, I remove the piece from the kiln and place it in a metal trash can with combustibles, I use newspaper). The flames will remove any oxygen from the glaze, bringing the color back to a copper. Within seconds the glaze will react with the air and start changing colors. When this starts, I cover the can with the lid and allow it to cool. I wash off any ash or residue. The piece is complete. The Flames “paint” the piece.

“Naked” or Slip Resist: The slip is designed to fall off the bisque piece. Heated to 1800 degrees or so, I removed the piece from the kiln and, again, place it in a can with combustibles. Once the paper ignites, I cover the can and let the smoke enters the clay through the cracks or any place that isn’t covered with the resist. Within minutes, I splash water on the piece which causes the slip to “fly” off the clay. Wash and seal to keep finger prints off the finished piece.

Horse Hair and Feathers: Heat the untreated piece to 1100 degrees. Remove from the kiln and place is on a heated brick. Place the horse hair and/or feathers on the hot piece and allow the carbon to be trapped in the clay. I have 30 seconds before the clay cools and will not trap any more carbon. Even the smoke that flows up along the piece can be trapped during those 30 seconds. Allow the piece to cool, wash off the ash and residue, seal the piece.

Since I use a lower temperature, the clay will not turn to “glass.” It will not hold water!

Every Raku Fired piece of artwork is unique.