|Monthly Tech-Tip |
These were fired at cone 04, top is this clay and the bottom one is L215, a terra cotta from Plainsman Clays. The extra glaze thickness on the top one was done to thermal-expansion-stress it and bring out shivering or crazing. Notice how many more pores there are in the L215 (bottom), this clay is clearly much denser. That appears to account for its very low measured porosity, 3% at cone 04. This is among the lowest we have ever seen for a material like this. I took these photos using the closeup feature on an iPhone 13.
Evaluating a clay's suitability for use in pottery
Would you like to be able to use your own found-clays in your production? Follow me as we evaluate a mystery clay sample provided by a potter who wants to do this.