[Wind n Wing]

Help ! I have a Dunan Kiln model #DK820X12, Serial # H00986 24 Amp 240 Volts fires to cone 8. This has been a work horse for a long time. It has a kiln sitter and timer. I noticed a few firings ago it wasnt coming up to temp (cone 6). So I thought maybe the cones I was using were old, (about 6 months) so opened up a new box and Happy Day everything seemed fine. Easy fix right? Last firing two days ago wasnt up to temp and the timer never moved. I usually set the timer for 13 hours and if everything goes smoothly the kiln sitter kicks off at 11 hours. I manually shut it off at 13 hours.

Now the question. After umpteen years of service what do I need to check first and then how do I go about refurburishing it. It is the perfect size for small loads and the brick and body are still in very good shape. There are no Kiln techs in this NE corner of Montana so it will be up to me and my handy husband to do the job. I also have a large studio kiln by Duncan and it is in good shape but probably could use new elements. If I am going to do one I want to do both.

Are there manuals available for these older model Duncans and where might I find them? Big Bertha is a DK-1029-2, Serial # 40320,
amps 45, Volts 240 fires to cone 8 and yes I have a dedicated electrial service for the kilns and only fire one kiln at a time.

Of course as many of you well know from personal experience this glitch is coming right when I am in the middle of heavy production. So any suggestions or pointing in the right direction will be greatly appreciated.

Thanks,
RJ

[clayshapes]

I'm not an expert at all, (and don't know why it says I'm 'advanced', next to my avatar, as I am a real novice!!) but my kiln, also an old Duncan, had the same problem you are describing...and new elements fixed it. Mine was also taking 13 or sometimes 14 hours to get to cone 6 before I got new elements --- now it's done in 8 or 9.
I'll be interested to hear some more expert opinions on this though. Good luck!

[icyone]

Sorry if this seems obvious but have you made sure all the elements are working?

[yedrow]

I'm no expert either, but it seems to me that if it is getting warm at all it wouldn't be the timer. If you can find a manual you may be able to find out how many ohms the elements use at optimal. Then take a test meter and see their resistance in ohms. This article may be helpful.

http://www.paragonwe...ter.cfm?PID=224

Also, Paragon own Duncan and they have manuals on their site. You have to scroll down a little, but I think they have a DK manual.

http://www.paragonwe...ion_Manuals.cfm

[jeffkuratnick]

Greeting from Paris Gibson Square Museum of Art in Great Falls!

I had a similar problem with a Cress Kiln - (the only difference is we have a digital pyrometer on ours) that wasn't firing to cone 6 as desired. After running some tests we figured out it most definitely was a fried element (our replacement ran about $50). If you know an electrician they would be able to determine kiln element functionality with a simple test.

Recommended steps to take:

1. Get in touch with an electrician and have them run a test on the element
2. Call the kiln manufacturer and order the appropriate element.
3. Call me at the museum if you have any further ?'s: 406.727.8255 X 305

Good Luck!

Jeff Kuratnick

[Wind n Wing]

icoyne - Yes, firing previous to the misfire was with witness cones and everything was good.

Yedrow - Went to the sites suggested and downloaded manuals.

Jeff - Will run tests and order new parts as needed. Next time I go thru G.F. will try and stop by. Im just a little N. of Glasgow.

The only thing I am still wondering about is the timer as to why it didnt work. Perhaps a new one is also in order.

Thanks everyone for the input. Guess Big Bertha will be getting a work out until I can get Baby Bertha up and going again.

[Wind n Wing]

clayshapes, on 21 July 2012 - 09:30 PM, said:

I'm not an expert at all, (and don't know why it says I'm 'advanced', next to my avatar, as I am a real novice!!) but my kiln, also an old Duncan, had the same problem you are describing...and new elements fixed it. Mine was also taking 13 or sometimes 14 hours to get to cone 6 before I got new elements --- now it's done in 8 or 9.
I'll be interested to hear some more expert opinions on this though. Good luck!

Clayshapes, 8 or 9 hours would be just lovely.

[icyone]

Wind n Wing, on 22 July 2012 - 08:12 AM, said:

icoyne - Yes, firing previous to the misfire was with witness cones and everything was good.

Element or relay? could of went bad in the misfire firing though

Have you checked the elements after you had the misfire?

[Wind n Wing]

icyone, on 22 July 2012 - 05:55 PM, said:

Wind n Wing, on 22 July 2012 - 08:12 AM, said:

icoyne - Yes, firing previous to the misfire was with witness cones and everything was good.

Element or relay? could of went bad in the misfire firing though

Have you checked the elements after you had the misfire?

Elements are working but dont know if they are coming up to temp.

[Mark C.]

I'll let others fine tune the electric woes but I can say with no doubts that this statement-
(the cones I was using were old, (about 6 months) so I opened up a new box)
Is not correct-cones are not like bread or milk and can last for more years than you or I . The key is keeping them DRY
Old cones (I have some over 30 years) work just fine-again you have to keep them DRY
I fire every week and go thru cones like butter but the odd temp ones are slow to use up and I have bought enough potters out to collect cones from yesteryear. These old cones work just as the new ones. Now if your milk is two month old throw it out-but keep the cones for your children to use-but keep them dry.
Mark

[Wind n Wing]

Mark C., on 22 July 2012 - 10:53 PM, said:

I'll let others fine tune the electric woes but I can say with no doubts that this statement-
(the cones I was using were old, (about 6 months) so I opened up a new box)
Is not correct-cones are not like bread or milk and can last for more years than you or I . The key is keeping them DRY
Old cones (I have some over 30 years) work just fine-again you have to keep them DRY
I fire every week and go thru cones like butter but the odd temp ones are slow to use up and I have bought enough potters out to collect cones from yesteryear. These old cones work just as the new ones. Now if your milk is two month old throw it out-but keep the cones for your children to use-but keep them dry.
Mark

Mark,

Good to know that cones dont get old. Just those who use them. LOL. My studio is in my basement and at certain times of the year things get slightly damp. I usually keep cones in their box with the foam packing. Now, is there a better way to store them and if they do get damp if I were to put them out in the sun would they dry out and still be good. The question is very simple but it is usually the simple things we overlook and take for granted. Since I am self taught I am sure there is alot of knowledge I have missed but am eager to learn.
Thanks
RJ

[Wind n Wing]

OK everybody, just finisherd firing Big Bertha the kiln I dont have problems with. Used a cone from the box I had been using for Baby Bertha and Lo and Behold the timer turned the kiln off at 13 hours instead of the kiln sitter working. The cone is white and unbent. Now I know that this kiln was operating just fine as last firing before this I used Witness cones. The only conclusion I am coming to is that the cones are the problem.
Mark says the cones dont get old so perhaps they have absorbed moisture? Would open up a new box but dont have any at the moment. I will be calling Archie Bray in the morning and ordering some. These are Orton cones and I have never had a bad box but guess there could be a first time. Any thoughts would be appreciated.

RJ

[yedrow]

I really doubt that 6 month old cones are bad unless you got them wet. I set my timer to 17 hours to bisque (3 hours to blow off pour water under 212 deg, 180/hr to fire). I'm just getting into electric firing, so don't put a lot of stock in my observations; but setting your timer to 13 hours seems kind of short to me.

[Mark C.]

Wind n Wing, on 23 July 2012 - 10:31 PM, said:

OK everybody, just finisherd firing Big Bertha the kiln I dont have problems with. Used a cone from the box I had been using for Baby Bertha and Lo and Behold the timer turned the kiln off at 13 hours instead of the kiln sitter working. The cone is white and unbent. Now I know that this kiln was operating just fine as last firing before this I used Witness cones. The only conclusion I am coming to is that the cones are the problem.
Mark says the cones dont get old so perhaps they have absorbed moisture? Would open up a new box but dont have any at the moment. I will be calling Archie Bray in the morning and ordering some. These are Orton cones and I have never had a bad box but guess there could be a first time. Any thoughts would be appreciated.

RJ

I think this conclusion is off
The timer turned of the kiln before it got to temperature it has nothing to do with cones- They call this a red herring-that means it has nothing to do with this.
I do not know what turns up big Bertha but if you can turn it up faster manually do so that way it fires off before the timer turns it off.
The kiln timer is the a chance safety shutoff so kiln does not melt down-You should give it more time or turn it up more (high heat sooner) so that its does not time out.
this is not a cone issue-Maybe a kiln sitter issue if its way out of adjustment but I assume thats not the case as you said this BERTHA WORKS FINE.
Bad cones are about as rare as seeing a Dodo bird.
Crank the timer to more time next time
Now wet cones can cause issues but they needed to get wet first not just from humid air-I live in humid air usually 80-100%.
Mark

[neilestrick]

There are a number of possible causes of the kiln not reaching temperature. First, start it up on high with the kiln empty and see if all the elements glow after a while. If they do, then chances are they are worn out and need to be replaced. The only way to know for sure is to check the resistance of the elements with an Ohm meter. You'll need to find out the resistance of the elements by contacting the manufacturer. Duncan kilns are now supported by Paragon Kilns. If any elements do not glow, there is a good chance that element is fried, or a connection in the control panel is fried. The cones are not melting because the kiln is not getting hot enough, not because of any problem with the cones. If your timer was not moving, then you likely need to replace the timer. But the timer not working will not affect the firing.

[Wind n Wing]

neilestrick, on 24 July 2012 - 07:18 AM, said:

There are a number of possible causes of the kiln not reaching temperature. First, start it up on high with the kiln empty and see if all the elements glow after a while. If they do, then chances are they are worn out and need to be replaced. The only way to know for sure is to check the resistance of the elements with an Ohm meter. You'll need to find out the resistance of the elements by contacting the manufacturer. Duncan kilns are now supported by Paragon Kilns. If any elements do not glow, there is a good chance that element is fried, or a connection in the control panel is fried. The cones are not melting because the kiln is not getting hot enough, not because of any problem with the cones. If your timer was not moving, then you likely need to replace the timer. But the timer not working will not affect the firing.

Thanks for additional info. All the elements are working, Called Paragon and got the reading for the Ohm meter. They also suggested a check on the volt reading at the wall with the kiln on. Going to check everything, plus got the costs of new elements. Will also be going to Paragons site to take a look at some videos on maintance and repair. Am also going to plant money tree in the backyard and water it well. My dream is a pair of electronic controled kilns. But thats in the future. Will let you know if tree grows and send everyone some seeds.

RJ