A self made electric kiln experiment.

This experiment – research and explorations of clay firing techniques was done as part of my MArch Architecture second year architecture portfolio.

After making a couple of sawdust firings I used the same fire bricks to make an electric kiln heated by four 750W electric fire elements, which were inexpensively acquired from a spares shop. Due to limited amount of time available the firing was on for 6 hours and peaked at lower than expected 575 degrees celsius in the middle of the kiln, then left to cool overnight. Judging from the fired objects it can be assumed that the temperature closer to the sides of the kiln was much higher – possibility of +100-150 degrees, since each fire element was tested to reach up to 800 degres celsius. The performance of the kiln could be improved by better insulating the kiln.

The temperature rise was controlled by gradually switching on each of the fire elements.

Two pieces with low fire blue glaze started to gain rich blue colour, whilst a piece with red glaze (cone 04 glaze) did not react to the low heat of the kiln. Two of three pieces made from Scarva PF520 clay completely burst into pieces. The last piece was left unglazed and became a cone 022 bisque ware.

The risk assessment was done prior to constructing a kiln in order to ensure a successful operation of the kiln and safe environment.

Experiment of firing clay in sawdust.

This experiment – research and explorations of clay firing techniques was done as part of my MArch Architecture second year architecture portfolio.

I did two firings of my clay pieces in sawdust, which are shown in two separate picture galleries at the bottom of this post. Each firing lasted around 15-20 hours. The second firing was reaching around 500-600 degrees celsius. I did not have a pyrometer during my first firing leaving me unsure of the correct temperature during that firing.

It was my first attempt to fire clay in a self made kiln. The experiment took place in Worthing, England at the beginning of January 2014.

The kiln was built from 80 firebricks inside a pit. The weather conditions were at my disadvantage, hence the covering from rain can be seen in some of the photos.

Some clay objects were sprayed with salt, some burnished with a spoon to achieve a glossy surface, some pieces were covered with orange peel, leaves and other combustibles, some were fired inside a flower pot filled with combustibles, some were just put in sawdust without any special application.

I believe the best result was achieved during the second firing. The piece which was inside a flower pot filled with combustibles (orange peel, tea and some leaves) achieved a yellowish carbonization in the place where it was covered with orange peel.

After the two firings the kiln was dismantled in order to use the fire bricks for a second experiment – making an electric kiln powered by electric fire elements, which will be described on a separate post.

Firing No. 1

Firing No. 2