If you point at the pictures you will get them bigger.
These are pictures from my wood-fired kiln. It has a volume of about 160 liters and
it's built using the "Downdraft" principle. The kiln is built with one layer of Porosil bricks and
then covered with 6 mm thick ceramic felt. The kiln's exterior is one layer of Poros standing bricks but these are
very sensitive to water so the kiln has to be completely covered when not in use. It takes about 4.5 hours to reach
1280 degrees C (2335 F). Up to 1100 C (2000 F) the damper is almost closed and the chimney is 50 % closed.
When 1100 degrees C is reached I uncover the chimney and almost completely open the damper. After the temperature reaches 1200 C (2190 F) I begin to use
kindling 400 mm long and from 20 to 40 mm thick. I warm the pieces over kiln embers before I add them to the fire.
The wood must be absolutely dry. It takes almost a year for the wood to get dry completely. At the end of the firing,
I have to put kindling into the kiln every 30 seconds. There is no time for eating or drinking. Only time for firing.
I have done firing when it was -8 C ( 17.6 F ) but it was very hard ........
Perhaps you want to know where the kiln is located ?
Answer: In Landvetter 12 miles east of Gothenburg in Sweden.
Lucky firing
Oxblood glaze
Halfway
The roof finished
I have now ( May 1997 ) finished a very close copy of the first kiln. That's because
my next project is salt glazing. I have not changed any measures of the first kiln
for they seem to be optimal. All firings in the first one have been so perfect
so I will not change any of them. The first salt glazing has to wait until end of
summer because the forest beside the kiln is so dry. Furthermore all moisture must
leave the bricks so there will be no steam explosions at the first firing.
The first saltglazing
At Saturday the 4th of October I made the first salt glazing. It was not a complete
success. I could not reach the right temperature and finally some part of the
fire hole crashed. That's because some bricks had cracked at the first test firing.
The fire door began to fall so it was not a good idea to continue firing. At that time the
temperature was between 1180 (2150 F) and 1220 (2230 F) and I put in 2 pounds of normal salt in the fire
divided equally at 4 intervals. When I had put in the salt, I covered most of the chimney
to let the salt have more time in the kiln. At the kiln opening, the day after,
I found that the temperature had been too low, but there were also some jugs
that were perfect. They had been done in a dark clay and had a beautiful shimmer.
Now the kiln is repaired and waits for next firing.
