Raku is an exciting firing technique involving removal of pots from the kiln at high temperature. The pre-fired pots are placed into a hot kiln, quickly heated up to about 1000°C and then removed using long tongs and a lot of protective clothing.
After removal from the kiln they are immediately immersed in combustibles, sawdust, peat, leaves, the local newspaper, within an enclosed chamber. This leads to an incomplete combustion known as ‘reduction’, which draws chemically combined oxygen from the surface of the pots and gives them their unique range of colouring.
It was traditionally used in Japan to produce bowls for the tea ceremony but the pots were left to cool without the post firing reduction, this latter being a development by potters in America.
Some of my raku fired work involves the use of a technique called slip resist. Clay slip is painted onto the pre-fired ceramic followed by a layer of glaze. When the work is removed from the hot kiln the glaze chills suddenly which makes it shrink and crack. During the reduction process smoke penetrates the unglazed areas including through the cracks in the glaze. The glaze is prevented from sticking to the pot by the unfired clay slip which is scraped away when cold, leaving only the memory of the smoke as a pattern.
Care of raku fired pots.
This type of low fired raku ware is porous and should not be used for liquids or food. It should not be displayed in strong sunlight as this can lead to bleaching of the dark tones.
The pots may be washed in warm water with a little soap or scrubbed gently with a soft nail brush to remove dust. They should be dried thoroughly before coming into contact with wooden or delicate surfaces.
For further care advice please contact me.