Debbie has been throwing bowls in her spare time. She's starting to get REALLY excited about firing them!
Last Saturday we fired up the kiln for the first time. This was not to fire any pots, but to:
A) Burn off oils and water on the elements and bricks, as recommended by the manufacturer; and,
B) See how hot the room will get.
The outside of the kiln didn't start to get really warm until about 3 hours in, and the kiln interior was about 2000F. There is a vent hole in the top, and newsprint held to the vent hole would FLASH into flame. But you could touch the firebrick, which was only uncomfortably warm. Impressive stuff, that firebrick.
Of course, with the kiln as a point source of heat, unless we ventilate it the room will eventually get to the same temperature as the interior of the kiln. So we have a box fan blowing OUT the window, which will pull air through the room to keep the temperature below the trigger point for the sprinkler. It will also make the kiln room a negative pressure zone, keeping the fumes from dissipating into the house.
It still got into the mid-80s by the time we were done. I'm not completely convinced that we won't have problems with the sprinkler head. After all, we are going to be running the kiln much longer, and not much cooler (Cone 6 instead of Cone 10). That's really only about 150F difference, which ain't much stacked up against 2345F.
I'm going to insulate the sprinkler head with a small box of styrofoam peanuts for the first firing. I just don't see pumping 300 gallons of water into the room to try to put out the "fire".