Test Kiln with no plug

[Molly B]

Hello! I have recently purchased a test kiln and it did not come with a plug or kiln sitter. I was thinking about buying a digital thermocouple to use (instead of/in addition to witness cones) and I wanted to know if I needed a plug if I am going to use the digital thermocouple in the peep hole? I guess what I'm getting at is does the digital thermocouple act as the plug? Thank you!

[neilestrick]

So you mean a peep hole plug? I typically fire mine with the plug open, to allow fumes to escape during the firing process. You could put the thermocouple in the peep hole, but you'd need to pack around it with fiber or it won't read accurately, in which case you wouldn't have an outlet for fumes. I would drill a hole for the thermocouple. Make it just big enough for the TC to fit.

[Molly B]

Yes, that's what I meant. Ok that makes sense, thank you so much! Is there any instance where I would need a plug? Or is best to just leave the peep hole open at all times?

[Mark C.]

Plugs are cheap or you can make one from a piece of soft brick

Edited June 3, 2022 by Mark C.

[neilestrick]

A lot of little test kilns are not very powerful, so it can be helpful to put the peep plug in during cone 5/6 glaze firings once you get to low fire temps, to minimize heat loss out the peep.

[Molly B]

OK thank you so much!