Firing the kiln is one of my favorite tasks of being a potter. Each glaze firing is done in the gas kiln I built in 2009. It takes about 9 hours to load the kiln, and about an hour to brick up the door. I’m always asked, “how many pots does it hold?” and well, that depends on how big my pots are! The stacking space consists of three 48″ tall columns of 12″x24″ shelves. I start loading pots and adding shelves at the bottom back of the kiln, and work my way up, then towards the front; each shelf can be made any height I need: 1″ for plates, 5″ for mugs, etc., and any size at all for the top shelf, where pots are aligned with the interior arch of the kiln.
The firing takes 14-15 hours to reach temperature, about 2350º F, there are times when you need to raise the temperature very slowly, other times you can power up more quickly. The last few hours I like to come to temperature fairly slowly, about 100º F per hour, so the glazes can develop interesting surface structure. The kiln cools for 2 days afterwards; I like to unload on on the third day. I prefer not to climb into a hot kiln, and to be able to handle the pots and shelves without gloves.
See my photo, taken while unloading my kiln in August, that’s the top of the middle set of shelves… all the pots have shrunk quite a bit in the firing. When I’m loading the kiln I want all the pots snug against each other, with very little space between for the best glaze results.
Watch the little movie to see what I see when I’m checking the atmosphere in the kiln near the end of the firing. I have put the kiln into “reduction” by closing the chimney damper in quite a bit and adjusting the gas/air mixture of the 4 burners. I am walking around to the back of the kiln, first checking the flame of my top back peephole, then walking around the chimney to the bottom back peephole. The kiln is white-hot inside, but in the flame you will see a tinge of green from all the copper glazed pots. One handed iPod touch movie, so please forgive the shaky aim.
It was a great firing, lots of nice pots. Porcelain vases and jars, dinnerware samples for a client, mini whiskey sipping cups, black and white serving bowls, a landscape-y platter I’m keeping for awhile… see the other photo – more of this I’m sure, I love it!
Next firing, dinnerware order plus… I hope to be unloading it right before or during the fall Cape Ann Artisans Tour, Columbus day weekend. Now, back to work… bowls await trimming down in the studio.