Thursday, August 5, 2010

Maiden Firing of a Gas Giant

Wow, finally time to fire up the big guy from Olympic. This is my new gas kiln that I purchased this past December. It has taken quite a lot of time to get to this point, being that I had to build a structure/shed for the kiln and have a gas pipeline put in.  It took quite a lot of time to get ready and read up on how to operate a fully manual kiln. This is quite an awesome kiln, capable of achieving 280,000 btu's of propane induced heating. Needless to say, firing it for the first time was quite eye opening!

Here are some before shots of some greenware and inside the kiln during loading. First level of shelves holds some small pots and test tiles.

The next level holds more of the same, with the addition of some small and medium ovals and a fun primitive soft rectangle pot.

Here in the photo below you can see that I placed the larger pots closer to the top. I nestled the bonsai pots inside each other to save space. The cone pack is placed in front of the side port for viewing during firing. In hindsight I think I will place this farther away next time so they are easier to see. 

The top level of shelves includes a couple of rustic slabs for forest plantings. 

Dual pyrometers monitor temperature variation between top and bottom of kiln, and the readings were recorded at thirty minute intervals.

The kiln reached temperature for cone 06 in the bottom half at 9:34, but I was having trouble seeing the witness cones to verify. I decided to run a bit longer to see if the kiln would even out in the top and I ended up over firing by about 2-3 cones. All pieces made out just fine though, no cracks or explosions to speak of. I guess I can't complain.

I may have to adjust my glazes a bit to help absorption due to the over firing, but I am holding my head high. Compared to firing an electric kiln with a kiln sitter, this was quite a feat.  I fired super slow up to 600 degrees, and managed to show a bit of finesse with the burners. Cooling slow was also important. This kiln retains a lot of heat and it helped to get through some critical stages.

The next firing will really test my firing skills. The glaze fire will be very tenuous, but I am always up for a challenge!

Check out this technique!