Question: Any suggestions for using witness cones when your kiln has a kiln-sitter rather than a controller? I have a small, old school doll kiln and can’t create a schedule. All I can control is on, off, length of time.

Put witness cones where you can see them during the firing

In that scenario, I recommend putting witness cones on every shelf where you can see them through the peepholes. Hopefully your kiln has a peephole (some don’t) and then you can load your kiln strategically so that you can see the witness cones during the firing and be present at the end when the kiln sitter goes.

I would always always watch the witness cones at the end of a firing because my glazes were so finicky and I needed a perfect hot cone six. If it was over-fired, my glazes would run. If it was under-fired, my glazes were matte and I did not like how they looked. So I was always present at the end.

Your kiln sitter can be unreliable

For one thing, you should never rely on your kiln sitter to shut your kiln off. There have been times where my kiln wouldn’t have shut off if I hadn’t been there to turn it off because the sitter cone had melted and stuck to the cone supports. I don’t know why this happened but it did happen, and the sitter was stuck and it wouldn’t have fallen. Luckily, I was there. I’m always there, watching my cones fall, and shutting the kiln off when my cones look perfect.

If you have a kiln-sitter kiln, that’s what I recommend. Be there, be present, and have visible witness cones where you can see them. You’re watching them (and you’re wearing your kiln goggles to protect your eyeballs). You’re watching your cones fall so that your kiln shuts off at the right time. If it shuts off early, you’re there and you can turn it back on until your cones fall and then you can manually shut it off.

How to turn your kiln back on if the sitter falls early

If you have never done this before, if your sitter goes and your cones aren’t yet melted properly, you just lift up the little weight mechanism that falls down. Lift that up, push the button back in, and then gently lower it down ensuring the power button doesn’t pop back out. That’ll allow you to turn your elements back on. (You can practice this while your kiln is not firing, without a small sitter cone – turn your dials on, lift the weight, push the power button in and then gently set it down so the kiln stays on.)

And then you’re watching your cones. As soon as your witness cones look the way you want them to, then you hit that weight mechanism to manually shut the kiln off. Push it in and the button pops out and your kiln is off.

So that’s my recommendation. If you have a manual kiln, you’re always using witness cones that you can look at during the firing. And you’re using those witness cones to determine when your kiln shuts off, not relying on the kiln sitter itself.

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