When something goes wrong with a kiln, it is easy to assume the worst. But from my experience, most kiln repairs are quick and far less expensive than you would expect.
For instance, a customer named Katie wrote, “I fuse glass in a Janus-1613. This morning I left a 1" plastic circular level on top of some glass when I fired the kiln. (I’m not a morning person, obviously.) I caught the error at about 738°F (392°C) when I noticed a horrible smell. A brief peek into the kiln showed the black level melted onto the glass. The floor of the kiln appeared charcoal colored. Previously it was kiln wash pink. I closed the lid, pulled out the peephole plug and unplugged the kiln to let it cool. What should I do to clean the kiln?”
I suggested vacuuming the kiln and firing it to burn off the plastic residue. “But do not vacuum the thermocouple,” I added. “The vacuum cleaner can damage the controller by sending a static charge through the thermocouple to the controller.” (The thermocouple is the small rod that extends into the kiln.)
Two days later, Katie wrote, “I’m delighted to report that the kiln issue appears to have been resolved successfully.
“The black material on the floor of the kiln did wipe off somewhat but not fully. It didn’t vacuum off. After wiping and vacuuming, and vacuuming and wiping, I fired the kiln. At 1385°F (751°C) the kiln floor still appeared dark, and an acrid odor continued to emanate from the kiln. By 1450°F (787°C) the floor was no longer gray and the odor was markedly reduced.”
(Top photo: After the mishap. Center: After cleaning and firing. Bottom: The melted plastic level.)