Western or American raku pottery is a process when you remove your ceramics from the kiln at a bright red heat and subject it to post-firing reduction (or smoking) by placing your work in containers of combustible materials, which blackens raw clay and causes crazing in the glaze surface. This is an amazing process that requires protective wear, an outside space and heat resistant tools!
This technique is extremely unpredictable, you have no idea what effect the smoke will have on the vessel, so it can be really exciting, but also disappointing. You can be consistent with practice, but you can often not get the result you are after.
The Raku Kiln
You can't just get your pots out of any old kiln, at such a high temperature. Many kilns when you open them at that heat, radiate heat in a way that trying to open them would be somewhat insane. You also can't use top loading kilns as the heat rises and would be overwhelming.
Extremely simplified steps to raku pottery
(This is intended as a guide and an explanation to the process, we do not recommend you follow these instructions at home without the help or guidance of a trained professional.)
- Choose your glaze and brush it on to your creation.
- Wait for the glaze to dry (put it on top of the hot kiln to speed it up)
- Place glazed pieces in the hot kiln.
- Watch through the peephole in the kiln for the glaze to melt, this can be as quick as 20 minutes, so keep your eyes peeled.
- When the glaze is molten, remove the piece with tongs. For traditional raku, the process stops here, you wait for it to cool and see your results. For more modern raku, the timing is now critical.
- While the glaze is still molten, place your pieces on top of your chosen combustible materials (torn up paper, sawdust or even onion skin!) All this has to be inside a special combustion chamber. Maybe a metal wash tub. Cover your piece again with more of your chosen burn-able materials and seal up your tub until the fire has gone out. What happens at this stage, is that as the fire goes out the reduction (lack of oxygen) int he atmosphere has created unique metallic looking or black crackled effects on the clay.
- Your pieces will be hot, when you want to take them out, so use the tongs still. Submerge your piece immediately in a tub of cool water. This prevents re-oxidation which would ruin all the lovely effects you've just created in your chamber.
- After a minute or two take the now cool pieces out and give them a little bath. Remove all the leftover ash and soot and marvel at what you've managed to create.