I’ve started thinking more about the firing of my ceramic sculptures as our exhibition gets closer. The pieces need to get fired two times, first for the bisque firing, and second for the final glaze firing. Both firings must be approached with caution because of how thick the work is. The first bisque firing will reach 1730 degrees Fahrenheit, and will takes around 5-6 days. The final firing will reach 2100 degrees, and will take 4-5 days.
The time of firing varies depending on how much moisture is in the clay as I bring it up to temperature. I check if moisture is releasing from the kiln by holding a piece of glass next to a spy hole and looking for build up of condensation. Once there is no condensation I know I can turn the kiln up. Another variable will be which type of kiln I use for the firing. In the past I have fired using electric kilns that are computerized, and can have a firing schedule programmed directly into it. I may use this type of kiln for some of the smaller sculptures, but I am also planning on using a larger gas fueled kiln for the bigger works.
I have fired many gas kilns, but every kiln is different. I will have to be careful about how quickly I bring the works up to temperature, and also pay close attention to the atmosphere (Gas vs Oxygen) within the kiln. It is crazy to think there is a possibility of blowing up the pieces during this process, but I must say I like the risk. All I can do is use my knowledge and experiences with kilns to make it go as smooth as possible, and maybe do a little dance for the kiln gods.