During the last firing, we had a very shocking, and potentially dangerous surprise. Midway through the firing, well after starting reduction and getting to around 1800 degrees fahrenheit, a piece of the kiln floor broke and fell into the fire box. This was a real scare since we didn't know the extent of the damage, and it was a VERY large piece that fell. Did the floor completely break? Did the pieces inside move? Could the whole stack have fallen over? It was nerve wracking but at the same time, we didn't have any choice. We didn't hear any shifting or feel anything move, so we continued and hoped for the best. Luckily, nothing was damaged in the firing, but we definitely dodged a bullet this time.
Once everything was unloaded, we could see the extent of the damage. The large fire brick we had used for the bottom had cracked and broken nearest to the flame and firebox, and with over 30 firings in this kiln, had finally given way. Luckily none of the other floor pieces were damaged, and we managed to hammer and chisel the piece out.
We are also lucky in the sense that because of the manner in which we built the kiln, we were able to remove the bricks above the floor, piece by piece, without having to worry about the entire walls or arch coming down. This means that with the extra new bricks we've picked up, we can slide one back into place without too much hassle.
This was a very powerful reminder of the fickle nature of wood firings and older forms of pottery, and how even though we're going back to the basics, things can definitely go wrong. We will definitely be keeping a much closer eye on the state of the kiln going forward and make sure she's not falling apart on us.
~Peter