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Hey everyone, I finally got the electrical hooked up for my used kiln so I'm almost ready to do my first bisque fire.  I'm wondering if I should do a test fire at my glaze temperature to make sure it gets up to temperature.  I've felt the kiln heat up when I bought it so I'm thinking I'll be fine without one.  I've seen someone suggest heating it up on high for 15 minutes to make sure the temperature constantly rises.  Not sure which route to go here, let me know what you think.  Thanks!

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@ThatTeenPotter Go ahead and fire it empty to cone 6. Unless you have a multi-meter and can check the resistance of the elements, firing it up is the only way to know for sure. Firing to bisque temps won't tell you anything about whether or not it'll get to cone 6, and you don't want to risk a bunch of pots stalling out at cone 3.

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@neilestrick Thank you, I'm going to run an empty cone 6 firing just to ensure it gets to temperature.  I do have a few questions though.  I was given a nice handheld pyrometer with the kiln.  Most thermocouples I see for kilns have a ceramic sleeve over the metal, this one is just metal.  It looks like they've used it in there before.  My question is , am I fine with the metal thermocouple or should I buy another type k with a ceramic sleeve on it.  I've also seen they have thermocouple mounting blocks on them.  I've seen a post you've previously commented on suggesting drilling a hole in the kiln for a permanent option.  I'm not ready to do that quite yet, can the mounting block sit in the peephole?  I've also explored options like getting a peephole plug with a thermocouple hole in it.

Also, can I leave the thermocouple in the kiln for the entirety of it's firing?  Thank you

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Yes, you can just stick in a peep hole, but pack some fiber around it. Long term it would be better to drill a hole in the kiln that is just big enough for it to slide in.

The ceramic tubes help keep the TC from shedding material into the kiln, however many of the handheld versions have the TC encased in a metal tube, and those don't generally shed. If your TC is two separate pieces covered in ceramic beads and welded at the end, those would benefit from a ceramic protection tube. If the TC looks like one smooth shiny tube, then it's already encased and the ceramic tube shouldn't be necessary unless you find that it's shedding metal bits into the kiln.

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  • 2 weeks later...
On 10/8/2020 at 3:41 AM, neilestrick said:

@ThatTeenPotter Go ahead and fire it empty to cone 6. Unless you have a multi-meter and can check the resistance of the elements, firing it up is the only way to know for sure. Firing to bisque temps won't tell you anything about whether or not it'll get to cone 6, and you don't want to risk a bunch of pots stalling out at cone 3.

Hi Neil,

I am in a similar boat. They are hooking up my three phase electricity for my used kiln right now and I'm wondering what I should do to test it. I was planning to do what you said and test fire empty to cone 6 to make sure the current coils can achieve that temp. Do I also need to test the accuracy of the thermocouple by firing to with cones appropriate bisque and earthenware glaze temp? I've been having trouble getting a full range of cones around here actually! I guess they aren't stocked because people aren't using them so much anymore? I was only able to get 03,04,6, and 7! I can order the others on line but it will take awhile for them to get here. So I'm wondering if I have to wait to test or whether I can test with incomplete cone packs. Also, should I wait to test the kiln (empty) until my ventilation is up and running? Can that significantly change the temp in the firing?

 

Thanks!

Caitlin

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@feistyfieryceramics Hi Caitlin, I fired my kiln for the first time Monday and everything was a success!  I decided on skipping the test fire and just loaded it up and did a cone 04 bisque and it worked perfectly.  I didn't use witness cones, just my kiln sitter and my extremely helpful thermocouple.  I did calibrate my sitter with a guage washer beforehand and it shut off exactly when it was supposed to.  I wish you luck with your first firing!

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6 minutes ago, ThatTeenPotter said:

@feistyfieryceramics Hi Caitlin, I fired my kiln for the first time Monday and everything was a success!  I decided on skipping the test fire and just loaded it up and did a cone 04 bisque and it worked perfectly.  I didn't use witness cones, just my kiln sitter and my extremely helpful thermocouple.  I did calibrate my sitter with a guage washer beforehand and it shut off exactly when it was supposed to.  I wish you luck with your first firing!

I'm glad your kiln worked out! I don't have a kiln sitter and I'm not really sure how I'd calibrate a thermocouple. Thanks for wishing me luck I need it!

 

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Cones, very handy - even if you don't have guide, firing, and guard cones, just the firing cone lets you know you were too cool, almost hit it, just right, a bit over, way over, way way over (no movement, a bit of movement, perfect arc, mostly slumped, completely slumped, a pool of yuck, eh?). 

I'm in the habit of taking notes - clock time and pyrometer reading; when compared to the cones, gives me an idea how to adjust, if necessary, e.g. I'm running up to 2110F, which gives me a just right cone five bend in the middle shelves, a bit less bend on the bottom and top shelves. I've been skipping the guide cone, and will start skipping the guard cone as well, as have been hitting cone five ok.

Perhaps once I've run another several dozen glaze loads I won't put cones on each shelf... we'll see (I hope).

Edited by Hulk
because
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On 10/22/2020 at 1:43 AM, ThatTeenPotter said:

and it shut off exactly when it was supposed to. 

Don't switch what works, but you can't really know if this is true without dem witness cones!

On 10/22/2020 at 1:37 AM, feistyfieryceramics said:

So I'm wondering if I have to wait to test or whether I can test with incomplete cone packs. Also, should I wait to test the kiln (empty) until my ventilation is up and running? Can that significantly change the temp in the firing?

Besides the first "test" firing to "ready" new elements without gases, I can't help but see a test fire as a waste of time.

To see if it gets up to your temp, only one centrally located cone is required, as heatwork and variations in temp top to bottom will change with the load mass (and vent). This is also why cones are ALWAYS required, at least the one like Hulk says.

But in the beginning, before you learn your clay and kiln, and it's results, you should have at least a guide cone and target cone in your peep, so you know when to look to shut it off a full cone before necessary. 

Since you can see these, guard cones aren't required in the peep packs. However, where you can't see, you should place packs with gaurd cones. It's the only way, specifically when new to kiln, that you will know your work isn't over fired in the unseen places.  It is possible to read melted pools of target cones, but for accuracy sake, and while learning, every bit of info helps.

Of course, eventually you will know your clay and glazes well enough to know when they are appropriately fired, but by then, you need cones to verify your elements aren't getting faulty.

So stand your little telltale soldiers strong, and remember they are your best line of defense when it comes to never offering bad products.

They are our best insurance policy.

Sorce

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