Click on the embedded slideshow, or click on this link to see the photos detailing the entire construction process.
I designed the kiln hoping for something that would fire quickly so that we can have the opportunity to offer this as a potential activity for school groups in the future, as well as being fuel efficient as possible so in order to be more environmentally friendly than a kiln that would take several days to fire. To this end, I think it was a success. The kiln fired in twelve hours. Below is a chart of the notes I took on the pyrometer readings throughout the firing process.
We pre-heated the kiln with a small fire in the firebox for about 12 hours, and then let it cool down overnight. We did this because some of the pots and saggars loaded into the kiln were still leather hard - not even bone dry yet, and we wanted to make sure we safely dried them out before heating them up past the boiling point of water.
The steep cooling curve was a bit of an accidental experiment. We left the air ports open on the firebox for a couple of hours and the kiln cooled dramatically faster than intended. Despite cooling really quickly through the quartz inversion range at around 570 Celsius, none of the coffee mugs had cooling cracks.
Here are some of the finished pieces:
