Lasse Östman, Swedish potter. Firing Page

part from 6ak-glaze (manipulated)

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My kilns

1. Electric kiln, 75L from Scandiaovnen in Denmark. This kiln I sometimes use for testing glazes or if I want to fire a few pots in another way than I normally do. 7kW effect.
2. Electric kiln, 210L from Naber in Germany. My usual kiln for oxidation firing of not so big pots. A very well built kiln but difficult to change elements. 18kW effect.
3. Electric kiln, 500L from Scandiaovnen in Denmark. The usual kiln for bisquit firing and glaze firing of large pots. 30kW effect.
4. My electric kiln "BIG". Self made kiln for large plates and bowls up to 1,1m diameter. 30kW effect.

Look at BIG! Preview

5. Propane gas kiln, 250L from Scandiaovnen in Denmark. 2 burners. I use bottled propane. This kiln I use for Copper Red, Celadon, Shino and a few other glaze types.

Firing Schedules

Oxidation

I use this schedule for nearly all my oxidation glazes, even the Crystal ones. If I want big crystals I will control the cooling, staying 1-5 hours about 1100 degrees Celsius. I do it very seldom.
I use the same firing schedule for all electric kilns, but of course they give some variations in the result. Kiln volume, placing of the pots, kiln ventilation and a lot more factors influences the final result.
I use Platinum Pyrometers to measure the temperature and have also computer controllers for all kilns.
I don´t use pyrometric cones for other purposes than watching how the different places in the kiln affects the temperature. There are warm and cool places. It can differ up to 20 degrees.

The last word by firing has my eyes - reading the heat color.
Well trained you can gauge when you have to shut off.

Reduction

My gas kiln is very simple. 2 atmospherically burners. The energy consumption is about 15 kilograms propane gas each firing.
At 800 degrees Celsius I begin to reduce rather heavy. Then I persist reduction until full temperature. 3/4 of an hour at top temperature with no reduction!
I have never had any problems with Copper Reds. They will be good red firing after firing. And I can refire a good Copper Red in oxidation in my electric kilns. The result will often be even stronger red, but a little more bright on the rim.
All Shinos and Celadons goes in this kiln, sometimes the Tenmokus.
A satin mat Crystal glaze in many colors also fires in this kiln. And sometimes there are Uranium blacks and Shün glazes.

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