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Does Firing An Electric Kiln With All The Plugs Damage The Elements?


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#1 Tom

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Posted 23 February 2011 - 11:30 PM



Hi All

This is a very specific question. A statement was made to me at a public ceramic studio. That firing an electric kiln with all theplugs in throughout the entire (cone 10) firing would damage the elements. I had never heard this before. I know that it can be bad for the glazes andat the very least the top plug should be out during the 1200 degrees for theburn off of organics in a bisque. But doesit damage the elements in a glaze or bisque firing to leave all the plugs in. provided that we are not trying to add fuelfor a reduction fire, That is well understood to be hard on the elements. I amsure there are some of you out there that know better then I. Lets here your thoughts.



Thank you

Tom



#2 Arnold Howard

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Posted 24 February 2011 - 09:30 AM

That firing an electric kiln with all theplugs in throughout the entire (cone 10) firing would damage the elements. I had never heard this before.


Elements last longer in an oxygen environment. Closing the peepholes for the entire firing would reduce the oxygen in the kiln, because the vapors from burning organics would remain inside the unvented kiln. In theory, this could reduce element life.

For best firing results, vent the kiln lid and leave out the peephole plugs at the beginning of the firing. After the venting period, insert the peephole plugs. (Leaving the top peephole plug out makes the Kiln Sitter tube last longer.) Or if you are using a downdraft vent, leave the lid closed all the way and peephole plugs inserted throughout the firing.

Sincerely,

Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com

#3 clay lover

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Posted 26 February 2011 - 07:58 AM

Good question, Tom.
I have been told many various things on this. It's nice to hear from an expert.

I had been leaving all the peeps out for a bisque and all in for a glaze. Then the Skutt rep said that both ways were hard on the kiln. It was working too hard to get to temp in the bisque with all out, and didn't have enough air for the glaze with them all in. So now I have every other one out both ways.

#4 Tom

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Posted 03 March 2011 - 01:13 PM

is some cases I have noticed that if I leave too many of the peep holes plugs out during a glaze fire that any pot too close to the hole may have a "cold" spot on it. I usually leave only the top plug out during the entire Glaze fire. In Bisque fire prop the lid open all plugs out until about 1000 degrees, or a light glow, then close the lid and all but the top plug in.

But still don't know for sure if leaving all plugs in will damage the elements and is it worse in bisque then glaze.

#5 Arnold Howard

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Posted 03 March 2011 - 02:38 PM

But still don't know for sure if leaving all plugs in will damage the elements and is it worse in bisque then glaze.


It is okay to leave all peephole plugs in after the venting period. The ideal is to use a downdraft vent.

Sincerely,

Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com

#6 Firemountaion Studios

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Posted 18 April 2011 - 09:50 PM

During the first stages of firing organic and sulfur compounds are burned off/released from the clay, causing that “rotten eggs” smell during bisque firing.

The natural sulfur in the clay forms sulfur dioxide, sulfides and sulfates which corrode your bricks and elements, as well as, items near your kiln. Trapping these sulfur compounds in your kiln can also effect your glazes, dulling both the colors and the surface of the glaze.

Your whole studio needs to be vented, breathing these fumes is not good lungs or your health.


#7 clayshapes

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Posted 19 April 2011 - 07:22 AM

During the first stages of firing organic and sulfur compounds are burned off/released from the clay, causing that “rotten eggs” smell during bisque firing.

The natural sulfur in the clay forms sulfur dioxide, sulfides and sulfates which corrode your bricks and elements, as well as, items near your kiln. Trapping these sulfur compounds in your kiln can also effect your glazes, dulling both the colors and the surface of the glaze.

Your whole studio needs to be vented, breathing these fumes is not good lungs or your health.


I find this thread confusing. I have an old Duncan kiln, and the instructions that came with it. My kiln is pretty small and has two peepholes - which I leave plugged throughout all kinds of firing, as instructed in the manual for this kiln. It doesn't say to leave plugs out at any time. The top hole is always open, though. No plug for it. My firings are fine. I installed an overhead, strong vent in the room, just above the kiln. Shouldn't folks just follow instructions for their particular kiln?

#8 Lucille Oka

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Posted 19 April 2011 - 03:03 PM

Hi All

This is a very specific question. A statement was made to me at a public ceramic studio. That firing an electric kiln with all theplugs in throughout the entire (cone 10) firing would damage the elements. I had never heard this before. I know that it can be bad for the glazes andat the very least the top plug should be out during the 1200 degrees for theburn off of organics in a bisque. But doesit damage the elements in a glaze or bisque firing to leave all the plugs in. provided that we are not trying to add fuelfor a reduction fire, That is well understood to be hard on the elements. I amsure there are some of you out there that know better then I. Lets here your thoughts.



Thank you

Tom


One of the good things about electric kilns is that they come with operation manuals. Unlike hand built, wood burning or fuel burning kilns which can be 'temperamental' based upon the design or lack of good design, electric kilns are manufactured by companies with kiln designers and engineers with electrical skills and knowledge. They have tested the kilns they manufacture in different configurations and temperature settings. They have determined the best possible firing method for all of the cone levels for bisque as well as glaze firing for the kilns that they manufacture. They have also tested how best to avoid over firing and overtaxing the elements, burning out electrical connections, switches and plugs. If you do not have a manual for the kiln you are using call the manufacturer and ask for a copy noting the kiln model number. Read the manual. If you have a kiln or use a school kiln or are about to purchase a kiln, order and read the manual. It is always best to follow the manufacturers’ instructions. If the operation manual says, “leave the top peephole open during firing”, leave the top peephole open during firing.


John 3:16
"For God so loved the world that He gave His only begotten Son, that whosoever believeth in Him should not perish but have everlasting life".

#9 gkillmaster

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Posted 15 April 2014 - 09:16 PM

I know this is a couple years old but I did my first electric kiln firing without the top peep hole plug and its a downdraft set up. Will this cause any problems.

Reading the manual, it sounds like this is an important firing to oxidize or "prime" the kiln.

 

Many thanks for any feedback about this.

 

Greg K.



#10 earthfan

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Posted 26 June 2014 - 06:46 AM

Our club kiln recently had to have an element changed after not many firings. The person who mended it said that it was because one of our members had been firing with both peepholes covered right from the start - no venting.



#11 neilestrick

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Posted 26 June 2014 - 08:09 AM

I know this is a couple years old but I did my first electric kiln firing without the top peep hole plug and its a downdraft set up. Will this cause any problems.

Reading the manual, it sounds like this is an important firing to oxidize or "prime" the kiln.

 

Many thanks for any feedback about this.

 

Greg K.

 

If you have a downdraft vent installed you should leave all the peep plugs in. Leaving one or more out will spoil the draft of the vent. The vent will bring in plenty of oxygen.


Neil Estrick
Kiln Repair Tech
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Owner, Neil Estrick Gallery, LLC
www.neilestrickgallery.com

neil@neilestrickgallery.com

#12 clay lover

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Posted 27 June 2014 - 08:25 AM

Neil, how does a down draft bent affect the controlled cooling ramps?  Does it make the kiln run more to keep the temp drop what is programed?






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