White clay - barrel firing

This weekend I tested firing some white clay. Last weekend Karma left her white clay here and asked me to dry some out for making grog. The temptation to try out the clay was killing me, so I made this quick and easy ceramic pot (Sorry Karma, hope you don't mind :P ). I wanted to test the clay without any grog. The idea behind adding grog to the clay is to make the clay stronger against "heat-shock" that may cause the clay to crack or burst. Because the clay doesn't have any grog it is crucial to let it cool down slowly.

During last week I also did a lot of research on pit-firing and decided to adjust my approach a bit. Instead of putting the salt against my pot (which will anyway burn onto the pot) I soaked some dry grass with salt. I also mixed some used coffee grinds into this mixture. Coffee is rich in Potassium and is therefore an excellent oxidizer to increase the heat in the sawdust where oxygen is short. I wanted to get a cold blue-grey (epic fail) by using a copper scrubber. Instead of red copper, I had a brass (yellow copper) scrubber in the cupboard. The brass left prominent neon yellow markings.

In the future I will fire my pieces using a foundation of salted sawdust or grass and coffee grounds.

Here is the photographs of what went down this weekend. Hope you like it!

Riaan Coetzee, 2015, Pit-firing white clay (front), Fired Ceramics

Riaan Coetzee, 2015, Pit-firing white clay (back), Fired Ceramics