The Kiln

The kiln is is a full down-draught design with double Bourry boxes at each side of a single chamber with exit flues to the chimney in the floor. Two bag walls direct flames to the top of the chamber.The flames are drawn down through the setting to the exit flues by the draft from a tall chimney.

The double Bourry boxes came about because a single box design for each side would have meant that either the fireboxes would have been too small for the kiln volume if wood length was kept to a manageable length, or if scaled up to a size suitable for the chamber volume meant wood length would be too long to comfortably place onto thehobbs. A central hob allowed the fire box to be large enough while the wood length was kept manageable. It has the added advantage of easily accommodating any wood cut a little too long.

Fire boxes on either side of the chamber were considered necessary to ensure pots were not “one sided” as can happen with some single fire box designs. Another benefit is when changing from the fire on the floor of the fire box to firing on the hobbs (a time when the kiln can be subjected to a sudden drop in temperature). In this design this changeover is staggered across four fire mouthes. giving plenty of time for each fire on the hobbs to take and get going strongly.

It has 2.8m3 (100cu.ft) of packing space. Drawings showing more construction details can be found here.

Firing

Firing takes 18 to 20 hours to reach cone 10 - 1300 Degrees C - and burns approximately 2 tonne of wood. It is fired once or twice a year and holds about 600 pots each firing.                                                                      Back to Technical Page