The Raku Process

The basic technique came to the United States from Japan in the 1950's. Artists who went over to Japan to study art discovered the raku process as it was known in Japan.

It's accomplished quite differently here in the United States, because of a process called reduction. That's when the pot is starved of oxygen so that a chemical reaction will take place in the clay and glazes and that's what gives the American style of Raku it's distinctive look.

The photographs on this page show Sue's pots heated to around 1600° F. in an old electric kiln that has been converted to gas. By looking into the kiln through a little chimney hole Sue can see when the glazes have melted, and that's when she removes them from the kiln, while they are hot!

Sue uses metal tongs to grasp a hold on the pot. The glazes are molten at this stage and quite often marks from the tongs will remain on the pot. One can see the heat that is contained in this pot.

The pot is removed from the hot kiln and placed into a reduction barrel.

The clay that is used for this raku process is gritty with sand, and this gives it a better thermal shock value, from the quick change in temperatures. In the barrel is combustible materiel like newspapers or sawdust and when the
pot hits that materiel it ignites.

Care has to be taken when dealing with a hot kiln, red hot pot and flaming burn barrel all at practically the same time!

The individual differences between temperatures on the pot and amount of reduction each pot goes through makes RAKU so special and so much a collectors piece. The barrel is quickly covered cutting off the oxygen supply, as a result the hot pot is searching for oxygen to create the fire and only finds it in the clay and glazes. So as an example, a copper oxide glaze will have the oxides burnt out and have the copper remain on the pot. The clay that Sue uses for raku is white, however once through the reduction process it turns black. This pot has a copper oxide glaze on the rim and inside and it has turned teal color because it was allowed to have more oxygen. The neck has no glaze and the body of this three legged pot has a crackle white glaze. On this firing Sue achieved excellent results with the crackle being dark and pronounced. The pot is removed from the burn barrel once the glazes are set, in about 15 minutes and placed into a water bath for cooling and handling. The pot has a layer of soot on it and this is wiped clean.