2 ciggies and a beer
Cooling the kiln is just as important to colour development in glazes as the firing. Here is an example of two of my moon jars glazed in a shino glaze with wood ash sprinkled on the wet glaze through a kitchen screen. Apologies to the purists but if it was good enough for Shimoaka it is good enough for me. Reference an old article in Contact Magazine by Edmonton potter Richard Selfridge " I do it for the ash!"Richard explains to Shimoaka why he fires for so long- for the ash. Shimoaka gestures that he sprinkles his on.
|Crash cooled/ clam cooled|
The pot on the left was "crash cooled". In other words post firing the peeps are left open, as is the damper and the burner ports until it drops to around 1900F. The one on the right was "clam cooled". The kiln is shut down, damper closed, peeps in snug and burner ports closed. So the result is a slower cooling.
My preference is the crash since I am not after matt surfaces and prefer the bright glossy look when the liquid glaze is frozen with a quick cool.
When we fired the wood kiln at Sheridan at the end of the firing we would fill the firebox, I would open the damper, leave the air open, open the peeps and I told the students to go have 2 cigarettes or a beer at the pub. That usually took the better part of 45 minutes when we would then clam up the kiln starting with the air on the firebox moving back to the damper.
I am teaching a Colours of Shino course here at Pinecroft in 3 weeks where we will fire pots in two gas kilns. One will be crashed and the other clammed. Let the students be the judge of their own cooling preference. They both can be beautiful if you are mindful of what you want for your pots. The more gray I see in my beard the more I like an oxidized cool.