Reduction cooling produces some amazing surfaces in wood fired ceramics as seen in the following pieces by Jonathan Cross and Mitch Iberg.
Johnathan Cross vessel from the Firebox kiln (Akagama)
Mitch Iberg clay tests from the Firebox kiln (Akagama)
Reduction cooling when overdone can create some less than desirable surfaces as seen below from the Idyllwild Ceramic Arts wood fire kiln – April 2003. Everything looked like crystalized charcoal. It actually grew on me over time, but the “boat” forms on the lower left were refired in a cone 04 bisque firing to bring color back to the pieces.
Fast forward to 2015 to vessels that were fired in the Firebox kiln and were an oily iridescent brown/black to blue/grey in color. The following vessels were refired in bisque firings to cone 04.
Here is one of my bottles showing the results of refiring to cone 04 in oxidation.
Three Jonathan Cross vessels refired in oxidation to cone 04. Amazing visual texture and colors that show tremendous potential for exploration.
This pot is made from half Greenstripe Fireclay, half Hawthorn Bond Fireclay, and additions of decomposed granite from the mountains of Idyllwild, California. Louise Allison Court wrote a great book on Shigaraki pottery – “Shigaraki-Potter’s Valley” and had some analysis of the clays. The closest I could get with existing commercial materials was the blending of the two fireclays listed here. This pot was almost completely black. Once it was refired and shown to Jonathan Cross, it inspired Jonathan to fire the three vessels shown above.