Cone 10 is the magical number--the point at which the stoneware I use vitrifies. Reach cone 10, and a pot becomes dishwasher, microwave, and oven-safe.
After bisque-firing beautifully load after load of leaf pots, I was ready to do some glazing. I did several test tiles, and tried out some stains on a couple of my least favorite pots. I switched on my electric kiln to a medium speed cone 10 cycle. 16 hours later, my kiln puttered along at 2000 degrees for a while before finally giving up and flashing an error signal.
I called a technician at the kiln company who promised to call someone here in Utah to have them come check out the kiln. That was yesterday.
Now I wait.