I am especially pleased with the way that the kiln behaved this time around. The firing itself took right under 11 hours, and considering that the overnight low was about 40 degrees during the firing and we had winds gusting up to 25-30 mph I am lucky that it only took that long. For those who don't know, I fire an old electric kiln that I converted to fire gas/wood.
Normally I would fire with wood alone, however firing in the city I have neighbors who are less than thrilled about the amount of smoke that is produced during the firing. With the addition of the gas burners I am able to heat the kiln up to around 700 degrees c before I start stoking with wood, this method produces much less smoke as at this temp the wood burns almost completely with much quicker. This also helps to save on the amount of gas that I use.
This type of kiln, especially on this old, cools very quickly under the best of circumstances. Normally this isn't an issue and in a couple of cases I have found that being able to unload the kiln 8 hours after firing without risk to the pieces was very helpful. On the other hand, when the overnight temperatures are forecast to be below freezing, there is a real risk of damage to pieces that were glaze fired from a very rapid cooling. Hmmmm... what to do, I have to fire as there is a piece that was for an order that is over a month old, hmmm... I GOT IT!
I'll wrap the kiln in pink fiberglass insulation when it is done firing.
Okay so I will be honest, I didn't really expect that this was going to work as well as it did. But I felt that I had to try something and this was what I had handy. Imagine my surprise when 12 hours after the firing was completed I checked the kiln and the outside surface of the kiln was too hot to touch. Now to be fair the I did plan the firing around the fact that the daytime temperature on cooling day was going to be around 54, but it was still breezy during the day so I was expecting the kiln to be much cooler than it was. This morning when I checked it a full 28 hours later it was still 53 degrees inside the kiln. This has never happened to me before and truthfully truly tested my patience as I have never had to wait this long to see inside the kiln.
This was my first look inside the kiln. The vase at 9 o'clock is the one "failure" the rest however came out very nicely and with the exception of one vase that had an ash glaze on it that didn't quite mature and needs to be refired everything else is a keeper.
Tall vase for an order. The browns came out a little darker than I expected but I am happy with it and I hope the customer is as well.
Tomato red tall large bottle. This glaze has always come out differently every single time, this is what it is supposed to look like but honestly I was beginning to think that it was never going to look this way, which is a problem since I have 5 gallons of it.
Large bottle vase with clear glaze over green slip. You can see where the copper in the slip started to flash red from the flames and reduction in the kiln, another first.
A squashed bottle with a hare's fur glaze.
These bowls were used to test out an amber glaze. I am happy with the way that they both turned out, I now have a couple of different choices to use as a replacement for the traditional honey glaze that was used over slipware that contained lead.
All in all I am very happy with the way everything turned out. It was a successful firing from many aspects and I believe that with the insulation I now have a safe way to fire the kiln more often over the winter. I also have a glaze that will do what it has been supposed to do, and a choice of glazes to use over the slipware pots. Well worth the loss of a couple of hours sleep.
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