|Looking through firebox|
We actually built up quite a bed of embers under the grate where the wood burns. Normally, we try to keep the bed of embers in check, so that air enters the kiln and gets preheated as it passes over the bed of embers. We keep two holes open at the bottom of the kiln, and we keep an eye on the height of the bed of embers, raking out coals if necessary, or pulling another brick out of the holes to allow more air to enter.
The kiln fires most efficiently with the correct amount of air entering over the bed of coals.
But at the end of this firing, we experimented with allowing the coals to nearly fill the entire area under the grates as we kept the firebox filled with wood. This seemed to keep the front of the kiln from rising in temperature, but allowed the back of the kiln to climb in temperature.
We actually had the back of the kiln higher in temperature than the front of the kiln. However, we ran out of wood before we could see if our technique could allow us to get the back up to the same as the front. We reached cone 9 in the back and cone 13 in the front.
We're unloading today.