Elementary
Jul. 15th, 2015 02:06 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
offcntrBeen getting complaints at Club Mud about our Skutt 1227 electric kiln, firing slowly and not wanting to make temperature on cone 6 glaze firings. One of our retired engineer members took a circuit tester to the elements and discovered that the resistance is three or four times what it should be, which means they need to be replaced. Since I did the last repair job on the kiln, I volunteered to tackle the job Monday while I fired my glaze kiln. Sandy Brown, a new member and former art teacher volunteered to assist.
Yeah, those look pretty corroded. Also beginning to droop out of the element channels.
The first step is to pull the hinge pin and remove the lid to a safe location. After that, turn off the breaker and open the switch boxes, so you can disconnect the kiln rings from one another. Always label the wires, so you know how to put it back together.
Because it was hot in the kiln room (also smelly: Karen was burning newspaper out of a sculpture) we took the top ring back into the glazing room to work.
We began by clipping off the power leads and crimp connector on the outside of the kiln, then carefully pulling out element pins with needle-nose pliers. We saved the pins; although the new elements come with pins, there never seem to be enough, particularly of the hook or staple variety.
Old elements are carefully removed, and the channels vacuumed with a HEPA-safe vacuum. (Conventional vacs let silica dust right through, and that stuff is bad for your lungs…)
Afterwards, the new elements are installed, pinning periodically to keep the whole thing from sproinging back out again. Once the element is positioned, we go back and place pins on either side of each corner, with additional hooks or staples for support in places where the brick is worn or broken.
Ceramic sleeves are installed on the outside of the kiln to prevent contact between element and metal jacket, then the ends are trimmed short and the power leads attached with crimped barrel connectors. Repeat until you run out of kiln rings. As it happens, our kiln is hardwired to the wall, so we can't unplug the center ring and take it somewhere cooler, so we balance it on boards on the 818 kiln next door and repair it in situ, taking frequent breaks to hydrate and cool down.
We started the project at 10 am; by 3:30 we're finished, including a lunch break. The manufacturer recommends an initial firing to cone 04 to settle the new elements in their channels, so we close it up and fire it off.
Yeah, those look pretty corroded. Also beginning to droop out of the element channels.
The first step is to pull the hinge pin and remove the lid to a safe location. After that, turn off the breaker and open the switch boxes, so you can disconnect the kiln rings from one another. Always label the wires, so you know how to put it back together.
Because it was hot in the kiln room (also smelly: Karen was burning newspaper out of a sculpture) we took the top ring back into the glazing room to work.
We began by clipping off the power leads and crimp connector on the outside of the kiln, then carefully pulling out element pins with needle-nose pliers. We saved the pins; although the new elements come with pins, there never seem to be enough, particularly of the hook or staple variety.
Old elements are carefully removed, and the channels vacuumed with a HEPA-safe vacuum. (Conventional vacs let silica dust right through, and that stuff is bad for your lungs…)
Afterwards, the new elements are installed, pinning periodically to keep the whole thing from sproinging back out again. Once the element is positioned, we go back and place pins on either side of each corner, with additional hooks or staples for support in places where the brick is worn or broken.
Ceramic sleeves are installed on the outside of the kiln to prevent contact between element and metal jacket, then the ends are trimmed short and the power leads attached with crimped barrel connectors. Repeat until you run out of kiln rings. As it happens, our kiln is hardwired to the wall, so we can't unplug the center ring and take it somewhere cooler, so we balance it on boards on the 818 kiln next door and repair it in situ, taking frequent breaks to hydrate and cool down.
We started the project at 10 am; by 3:30 we're finished, including a lunch break. The manufacturer recommends an initial firing to cone 04 to settle the new elements in their channels, so we close it up and fire it off.