Slowing down the flame in the first chamber will probably improve the next firing. Today I started playing around a bit with a wall in front of the exit flues. Old bricks from a kiln car floor seem like they are perfect for this.
The reason for doing this is that during the first firing, the flame was moving through the kiln too quickly, with this wall I’m hoping to slow it down a bit, and break it up. In addition, to err on the side of caution, we made the exit flue volume quite a bit larger than the primary air. Now that I know there is more than enough draft via flues and chimney, experimentation can be begun to slow down the draft.
Building the wall in front of the flues, reducing the exit flue volume, and dampering the chimney will all be tried this next go around. Damper will be placed over the top of the chimney, so that reduced flow will not effect chimney temp and cause a reduction in pull.
I’m also thinking about eliminating the rear setting of shelves in lieu of tumble stacking in the back, with larger pieces. The two pair of stoke holes in that area will allow for good coal buildup on the front and rear of the ware area. Plus, setting those heavy shelves in that low narrow space is a real back breaker.