"A Method to the Madness"

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My guru, (Ivan Anderson) of Raku at Mendocino College used to repeat one of the lines from Forrest Gump, well not quite verbatim but very effective none the less. "Raku is like a box of chocolates. You never know what your gonna' get." That's true and certainly the elements do take over but I have learned to control the elements a little more.

Firstly, the quality of the glaze is paramount. Mixing the proper percentages of each element is very important and of course experimenting with each mixture until you get the very best, or the quality you desire. You can put a lot of work into a piece. Don't just slap some mixture on and fire it. Do some testing. I make small tiles about 3" x 3" for testing. Make sure to put two coats of glaze on the piece for best results. A rule of thumb, use the thickness of a pin tool to gauge. That would be about 1/16 of an inch.

Secondly, control of oxidation/reduction both in the kiln and the secondary reduction chamber are a little harder to control. While firing the glazed piece in the kiln, the control of oxidation/reduction can be controled by closing off the exhaust from the kiln. We used a piece of old kiln shelving on top of the kiln. Close off more, higher percentage of reduction. Close off less, higher percentage of oxidation.

Then in the secondary reduction chamber, these elements of control change. What kind of fuel are you using? Paper, dried leaves, dried wood chips, sawdust? There is a myriad of possibilities and each will have a different result. I have discovered the secret is the size of the secondary chamber. The can must be as close to the size of the piece as possible. In other words, if you have a piece 6 inches across and 12 inches high, us a 5 gallon can. I started out using any size I could get, usually a 20 gallon size. There's a lot of room in there when you are trying to control the environment while firing a small piece. Cans come in various sizes so there is quit a good selection out there.

I personally use newspaper, but I don't just throw a bunch of torn up paper in the can and drop the piece in. There's a method to my madness and a greater amount of control.

The method goes something like this. First I place a fire brick or two, depending on the size of the piece, in the bottom of the can. Then I shred the newspaper into 1-2 inch pieces and place as much as possible around the outside edge of the brick. Then I take whole sheets of newspaper and line the can, fold them over the outside edge, leaving the bricks exposed and covering the shredded paper. I crumple a few pieces of newspaper and place them around the bricks at the bottom for ignition. Make sure there is enough material to give an initial good hot fire. Ok, we now have an ideal reduction chamber for control of the intensity of the copper lusters. This method works great if you want your piece to have a shiny copper luster. But the method is not complete.

Make sure you are using the proper safety equipment to protect yourself, especially the face mask.

The kiln is on. It's reached the 1800 degrees required for this to work. You want to be quick in taking the piece out of the kiln. You don't want it to cool too much. Place the piece on the bricks in the can. The newspaper will immediately ignite. Use extreme caution here. But don't just put the lid on. Have it in your hand and ready. While the fire is burning in the can, you will be watching what is going on. Look at the glaze. The object here is to get the glaze hot. The glaze will fine out. Once the glaze looks the way you want, reduce the oxygen by putting the lid on, creating a reduction atmosphere. Leave the lid on until the can has cooled considerably. Take out the piece and clean. If this has been done properly, you will have a highly reduced glaze. If it is of the copper lustre nature, it will be like a new shiny penny. The copper glaze recipes on my web site, http://earthstonearts.com/aboutraku.html were formulated for this purpose.

Experimentation is the key to good control and consistant results.

COPPER LUSTER

Colemanite-410 Grams

Cornwall Stone-90 Grams

Cobalt Carbonate-15 Grams

Copper Carbonate-2 1/2 Grams

This recipe can be reduced by halves.

**If you want more of a greenish result, wait longer to take the piece out of the kiln and use less secondary reduction fuel.

Good Luck and above all, have FUN!