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Safety while electric kiln is firing


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No. The only time I ever had anything go wrong was when the kiln wasn't reaching temp. The end result of that was the kiln soaking at a low temp. I guess it could happen the other way but I don't stress about it.

 

 

having seen the aftermath of kilns that have over fired due to the fact that they were left unattended, I can absolutely say that this is terrible advice. At very least you should be around to make sure your kiln has fired off--not doing so is asking for an accident that at best will ruin your kiln and at worst could cost you your studio. Computer controlled kilns can do this as can kilns that are sitter controlled--everything is fallible.

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I am wondering if others worry about going away for a few days while a kiln (electric, programmable) is firing. I am not inclined to worry about this....should I?

 

 

All kiln manufacturers recommend that you monitor the kiln during firing. Digital controllers are very reliable but not perfect. Suppose the thermocouple is bumped with a shelf and pushed into the firebrick wall. The controller won't be able to detect that error and will to some extent overfire the kiln. This is because the firebrick wall is cooler than the firing chamber.

 

Sincerely,

 

Arnold Howard

Paragon Industries, L.P., Mesquite, Texas USA

ahoward@paragonweb.com / www.paragonweb.com

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I would never leave a kiln unattended. When I am firing electric (bisque) or my gas (cone 10) I stay near and check every 30 minutes. I also take that time to record in a kiln log what I am observing, temp, gas pressure. Good luck, but I would never leave during a firing.

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No. The only time I ever had anything go wrong was when the kiln wasn't reaching temp. The end result of that was the kiln soaking at a low temp. I guess it could happen the other way but I don't stress about it.

 

 

I agree. Don't stress about it unless you tend to worry about little things like burning your house down.

 

Jim

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I am wondering if others worry about going away for a few days while a kiln (electric, programmable) is firing. I am not inclined to worry about this....should I?

 

 

This is a REALLY BAD IDEA

Just wait and fire the kiln when you return

 

The kiln can mis-function for many reasons and never turn off until the place burns down and the power is cut from it.

Lets see I have never fired a newer controller kiln but have had the sitter mis-function and over fire until I turned it off more than once-I have had the feed wires melt-relays burn out-breakers burn up/shut off

 

If you are not inclined to worry about leaving a fire going or toaster running or car idling or bbq going or candles burning for a few days while away

It'd not worry about a kiln as well

 

 

Just trying a humor angle on the answer

Mark

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I set my classroom kiln to candle over night, and will leave during the cool down, but that's it. I know the odds of anything bad happening are pretty slim, but I don't want to be the teacher, that burns down half school......I'll leave that to the Chemistry or Industrial Tech teacher.

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I set my classroom kiln to candle over night, and will leave during the cool down, but that's it. I know the odds of anything bad happening are pretty slim, but I don't want to be the teacher, that burns down half school......I'll leave that to the Chemistry or Industrial Tech teacher.

 

 

Even that's not a good idea.

 

Jim

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I'm not suggesting that it's a good idea- I know that it's not- but I DO leave my electric programmable kiln to fire over-night and shut itself down. I do worry about the possibility of losing my studio, but it's a separate old building, on a property 15 minutes from my home. It just doesn't work for me to stay. Mine is a Bartlett controller and you can program an alarm to go off at a particular temperature. I used to set up a baby-monitor next to the kiln and it would beep when I needed to go check. Great feature.

 

For the best repeatable results with a finicky glaze, you should watch the cones and shut it off yourself. But remember that the worst gases for your health are those that you cannot smell, at the end of a firing. Especially in a glaze firing if there are metals in your glaze. No matter what kind of ventilation you have, they're still there. Try not to hang out with a firing kiln any more than you absolutely have to.

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I am wondering if others worry about going away for a few days while a kiln (electric, programmable) is firing. I am not inclined to worry about this....should I?

 

 

As my workhorse kiln has no kiln setter and is only fired by cones, I check it constantly. Especially from cold to bright red. Then I check it from orange to cone 6 drop. Then I fire it down to dark color and off. I have had this kiln for over 30 years and have treated it well. It is an L&L and the brick is in great shape as are the holders-some replaced. Never had a problem other than oversleeping once.

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I set my classroom kiln to candle over night, and will leave during the cool down, but that's it. I know the odds of anything bad happening are pretty slim, but I don't want to be the teacher, that burns down half school......I'll leave that to the Chemistry or Industrial Tech teacher.

 

 

I did the same, many many a time. I made certain that nothing was around the kiln space, that the vent and blowers worked, and that the janitor knew I was candling on purpose. I even told him that if he noticed anything suspicious to not get near the kiln but shut it off at the breaker box, which I had well marked. Ceiling and walls in my basement room were industrial height, and made of concrete and brick.

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I am wondering if others worry about going away for a few days while a kiln (electric, programmable) is firing. I am not inclined to worry about this....should I?

 

 

OK so I have not done this yet, but I have gone to sleep while the kiln in my garage has not quite completed the firing. I hear ya, that's a bit risky. I appreciate the advice.

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I make sure I come back for the last hour of the firing on my automatic electric.

 

My next controller will have the Internet hook up so I can watch the firing progress on line.

 

 

smile.gif

 

 

So, do you really think something can go wrong only during the last hour of a firing? You usually don't hear about it because potters don't brag about burning up kilns, studios or houses but it happens more than you probably think. Talk to anyone who has been potting more than a few years and they probably know of at least one fire caused by someone leaving a kiln unattended. I know of several kilns causing fires or people coming in to find a kiln still firing but so hot that it is ruined. A couple of years ago I had just turned a kiln on and was working at my desk when my desk lamp started flickering. I turned it off but then the surge protector to my computer started beeping. Obviously, something was going on with the electricity. I went outside just in time to put out a fire in my kiln shed. Part of one wall was flaming and the ceiling was about to catch on fire. I put the fire out with the electrical fire extinguisher I keep near the kilns. (My electric kilns are in a shed that would probably cost less than $1,000 to replace.) Somehow the plug to this kiln had worked loose enough to expose a little of the plug prongs which caused an electrical arc that started the fire.

 

Jim

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I went outside just in time to put out a fire in my kiln shed. Part of one wall was flaming and the ceiling was about to catch on fire. I put the fire out with the electrical fire extinguisher I keep near the kilns. (My electric kilns are in a shed that would probably cost less than $1,000 to replace.) Somehow the plug to this kiln had worked loose enough to expose a little of the plug prongs which caused an electrical arc that started the fire. Jim

 

I have heard of electrical fires that involved a kiln. But I have never heard of a fire caused by the heat from a properly installed kiln. If a kiln overfires, the elements eventually burn out, and the kiln then cools down. But the heat is contained within the kiln.

 

When the kiln is not in use, the lid should be kept closed. We also advise disconnecting the power.

 

Sincerely,

 

Arnold Howard

Paragon Industries, L.P., Mesquite, Texas USA

ahoward@paragonweb.com / www.paragonweb.com

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I'm not suggesting that it's a good idea- I know that it's not- but I DO leave my electric programmable kiln to fire over-night and shut itself down. I do worry about the possibility of losing my studio, but it's a separate old building, on a property 15 minutes from my home. It just doesn't work for me to stay. Mine is a Bartlett controller and you can program an alarm to go off at a particular temperature. I used to set up a baby-monitor next to the kiln and it would beep when I needed to go check. Great feature.

 

For the best repeatable results with a finicky glaze, you should watch the cones and shut it off yourself. But remember that the worst gases for your health are those that you cannot smell, at the end of a firing. Especially in a glaze firing if there are metals in your glaze. No matter what kind of ventilation you have, they're still there. Try not to hang out with a firing kiln any more than you absolutely have to.

 

 

 

 

 

Your bartlett controller also likely includes a feature that allows you to start your firing on a delay so that you can time it so you are present for the duration of the firing.

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I went outside just in time to put out a fire in my kiln shed. Part of one wall was flaming and the ceiling was about to catch on fire. I put the fire out with the electrical fire extinguisher I keep near the kilns. (My electric kilns are in a shed that would probably cost less than $1,000 to replace.) Somehow the plug to this kiln had worked loose enough to expose a little of the plug prongs which caused an electrical arc that started the fire. Jim

 

I have heard of electrical fires that involved a kiln. But I have never heard of a fire caused by the heat from a properly installed kiln. If a kiln overfires, the elements eventually burn out, and the kiln then cools down. But the heat is contained within the kiln.

 

When the kiln is not in use, the lid should be kept closed. We also advise disconnecting the power.

 

Sincerely,

 

Arnold Howard

Paragon Industries, L.P., Mesquite, Texas USA

ahoward@paragonweb.com / www.paragonweb.com

 

 

I am direct wired, so I always use the circuit breaker to cut all power to the unused kiln.

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I have heard of electrical fires that involved a kiln. But I have never heard of a fire caused by the heat from a properly installed kiln. If a kiln overfires, the elements eventually burn out, and the kiln then cools down. But the heat is contained within the kiln.

 

When the kiln is not in use, the lid should be kept closed. We also advise disconnecting the power.

 

Sincerely,

 

Arnold Howard

Paragon Industries, L.P., Mesquite, Texas USA

ahoward@paragonweb.com / www.paragonweb.com

 

 

Ditto. Every fire I have heard of came from the wiring in the walls, the plug, or from something combustible being too close to the kiln. A properly installed kiln cannot melt down. Sticky relays are somewhat of an issue, but the odds of more than one sticking are extremely low. The only time I have seen a sticky relay cause overfiring was on a 18" tall kiln going to cone 06 where one of the two relays stuck. Even then it did not melt the clay, just made the glazes run a bunch. The most damage happens when the clay melts and flows into the bricks.

 

On a 27" tall, 3 relay kiln, if one relay sticks it will just prevent the kiln from cooling completely. It usually hangs out around 1400 degrees or less depending on the size of the kiln. If two relays from neighboring rings of the kiln stuck it could cause those areas of the kiln to overfire a bit if the shelves were tight, but not likely enough to puddle a cone 6 clay. I think at worst you would only ruin shelves. You're probably more likely to win the lottery than have 2 relays stick at the same time. Zone control comes in handy here because it's easy to see if a section is running hot, and once a section gets too hot you'll get an error code that will shut down the firing.

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I set my classroom kiln to candle over night, and will leave during the cool down, but that's it. I know the odds of anything bad happening are pretty slim, but I don't want to be the teacher, that burns down half school......I'll leave that to the Chemistry or Industrial Tech teacher.

 

 

I did the same, many many a time. I made certain that nothing was around the kiln space, that the vent and blowers worked, and that the janitor knew I was candling on purpose. I even told him that if he noticed anything suspicious to not get near the kiln but shut it off at the breaker box, which I had well marked. Ceiling and walls in my basement room were industrial height, and made of concrete and brick.

 

 

That's exactly what I do. The area is cleared of combustible materials, and I give the custodial staff a heads up. I also have a program set on a delay, so it doesn't even start warming, until the middle of the night. By the time I get there in the morning, it's not hotter than an oven. Luckily, my kiln is wired directly into its own box, and none of the wiring is inside a wall. I do kill the box for the summer, though I could honestly do it more often. Another good point, is keeping the kiln lid closed, when not firing. I am terrible at this. I unload, and just leave the thing ajar. There's no reason I do so, other than the end of the term, when I turn around and refire. Time to make some changes!

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