Did I just ruin my first kiln load?

[Pat B.]

I did a successful test firing of my new L&L electric kiln. Yay! Then yesterday I loaded all my mason stained test tiles for the first bisque run. I put 105 tiles standing up in holders I made.

I'm in upstate NY and the kiln is in an unheated shed.  The temperatures for the test firing had been in the mid-30s during the day but down into the teens at night. I was able to keep the temperature above freezing (to protect the controller) by running a small electric heater until the kiln reached a high enough temperature to heat the shed on it's own.

However this week it's much colder so I'm going to wait until things warm up a little before firing the bisque run. I figured I'd load it up and just wait.

Today I read that you shouldn't let greenware freeze. The test tiles were dry, although I did sponge around the edges that morning so I guess it's possible that there is a little moisture in them.

Did I ruin them? I just went out to look at them and don't see any cracks. Are they likely to crack when I get to the glaze run? I spent a lot of time making serial dilutions of 24 different stains and I don't want to lose them. If I have to I can re-hydrate them one at a time and remake the tiles. What do you think?

[Mark C.]

If the tiles where dry you are fine.You will know if the clay freezes and has moisture in it as they come apart.I think you will be fine.

[liambesaw]

This what what frozen/ruined greenware looks like:

[Callie Beller Diesel]

You also don’t really need to wait to fire it. The kiln won’t use noticeably more power. Just do the same thing you did with the space heater to get it going. I’ve fired when daytime temps were in the -20 C (-4F) range. No ill effects or outrageous power bills.

[Pat B.]

Thank you to Mark C. for calming my anxiety and to liambesaw for the pic, now I know what to look for.

Wow. @Callie Beller Diesel, I can't imagine even going out to the kiln shed in -4F temps (which is what it was here last night!).

My understanding is that you have to keep the controller above freezing so I kept the electric heater on until the kiln heated up the shed on it's own. Trouble is that it took all day before the kiln had any effect on the shed temperature! I actually stayed up until 1am waiting for the shed temp to rise so I could go turn off the heater and go to bed. I wasn't willing to leave the heater on overnight unattended since it's pretty old. I was actually surprised that the kiln didn't heat the shed sooner/better. Even at the highest kiln temperature, in the last 2 hours of the firing that next morning, the shed only got to 55F (outside temp was probably 20F then).

My electric heater is extremely old and I don't think it could take colder temps than the 20-30F I used it in. The shed is  not insulated and has gable vents, so keeping the temperature up is quite a problem. Maybe I need to upgrade my heater ... or cover the gable vents ... or wait till Spring ;D.

[Callie Beller Diesel]

1 hour ago, Potterhead said:

, I can't imagine even going out to the kiln shed in -4F temps (which is what it was here last night!).

You’re not hanging out there for longer than it takes to do a quick check, lol! And even in my neck of the woods, it’s not something that happens often.

I’ll confess my kiln is a manual so I don’t have to mess around with the space heater thing, but it is in an uninsulated tin garden shed with no door. It’s protected from the wind.

If it’s just the controller that needs to be kept warm, I’d be inclined to create a little shelter around the heater and the controller unit in order to speed things up. Just jig a little tent with a space blanket that’s easy to move and doesn’t take up room.

[oldlady]

potterhead, you just created a marvelous advertisement for the kiln manufacturer.   what good insulation, heat the pots, not the air outside the kiln.