joan woodward on sat 30 oct 04
Hi Everyone,
Here's an experience new to me. I've got a Skutt 1027-3 computer controlled kiln. I fired it yesterday on the same ramp/hold schedule I always use (based on Ron & John's recommendations) which takes approximately 10 1/4 hours. For some reason it took 12 hours and the bottom and middle shelves, not surprisingly, over-fired. Lots of ruined pots, less than 2 weeks before a major sale (natch). And yes, I was guilty of leaving the house during the firing. Yet when I double-checked to see if I had put in a different program, the numbers were the same as always.
I've got 2-3 more glaze firings before the sale. Other than being here during the firings so I can check the temperatures, what else can I do? Do I need to check witness cones through the peep holes?
Any thoughts (along with moral support!) greatly appreciated.
Joan, in Grand Junction, Colorado, where the sun hasn't been shining nearly as much as usual
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The Bedfords on sun 31 oct 04
'Here's an experience new to me. I've got a Skutt 1027-3 computer
controlled kiln. I fired it yesterday on the same ramp/hold schedule I
always use (based on Ron & John's recommendations) which takes approximately
10 1/4 hours. For some reason it took 12 hours and the bottom and middle
shelves, not surprisingly, over-fired. Lots of ruined pots, less than 2
weeks before a major sale (natch). And yes, I was guilty of leaving the
house during the firing. Yet when I double-checked to see if I had put in a
different program, the numbers were the same as always.'
Joan, I have agonizingly experienced the same thing...same ramp firing
schedule and terribly overfired pots.
My variable in this equation was not a new kiln, but a new thermocouple
installed in my Skutt 1027.
In several sacrificial/experimental firings with witness cones I discovered
that this new thermocouple was the culprit.
It was giving a different read on the computer controller from my previous
thermocouple.
I am now firing with about 70 F. lower temperature programmed into the
computer controller to get cone 9 like I used to.
Hope this helps.
Regards
Lee
Canyon Creek Pottery
Golden, B.C.
annsemple on sun 31 oct 04
Joan
If you have switches so you can turn down the heat in the middle of the =
kiln and leave the top and bottom on high, it will get you through =
another firing or two. The firings will take longer.
Meantime, order new elements!
Ann
Ron Roy on mon 1 nov 04
Hi Joan,
I wonder if your top elements are shot?
Turn on your kiln - empty - lid open - and watch to see if the top element
glows when the others start glowing - set your controller to a high ramp
speed - like 400C per hour - don't forget to unprogram that after.
Could be you need a new element.
Yes - always check cones.
RR
>Here's an experience new to me. I've got a Skutt 1027-3 computer
>controlled kiln. I fired it yesterday on the same ramp/hold schedule I
>always use (based on Ron & John's recommendations) which takes
>approximately 10 1/4 hours. For some reason it took 12 hours and the
>bottom and middle shelves, not surprisingly, over-fired. Lots of ruined
>pots, less than 2 weeks before a major sale (natch). And yes, I was
>guilty of leaving the house during the firing. Yet when I double-checked
>to see if I had put in a different program, the numbers were the same as
>always.
>
>I've got 2-3 more glaze firings before the sale. Other than being here
>during the firings so I can check the temperatures, what else can I do?
>Do I need to check witness cones through the peep holes?
>
>Any thoughts (along with moral support!) greatly appreciated.
>
>Joan, in Grand Junction, Colorado, where the sun hasn't been shining
>nearly as much as usual
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
joan woodward on mon 1 nov 04
Thanks, Ann. But I don't have switches! Another kind clayarter suggested thermocouple problems. Which is more likely, thermocouple problems or elements? Especially since on my bisque firing yesterday, there was a considerable discrepancy between my witness cones and the temperature readout.
Really appreciate the help.
Joan
annsemple wrote:
Joan
If you have switches so you can turn down the heat in the middle of the kiln and leave the top and bottom on high, it will get you through another firing or two. The firings will take longer.
Meantime, order new elements!
Ann
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joan woodward on mon 1 nov 04
Lee responded kindly to my "firing gone wrong" post by telling me that the culprit in his case was a new thermocouple. Unfortunately, I don't have a new thermocouple, but maybe it's my old one?? I just emptied a 2-shelf bisque firing. I used an 05 cone firing mode which usually gives me an 05 1/2 to 06 firing. The temperature never got higher than 1879 F, the firing took about 15 minutes (at 06 in this case) but the bottom shelf fired to a full, touch the shelf 04! This is obviously not a tragedy in itself, but I can't have a 2 cone variation in my glaze firing. Any more ideas gratefully accepted! Three more glaze firings needed before my upcoming sale.
Now I have two things to be nervous about: my kiln AND the election!
Joan
The Bedfords wrote:
'Here's an experience new to me. I've got a Skutt 1027-3 computer
controlled kiln. I fired it yesterday on the same ramp/hold schedule I
always use (based on Ron & John's recommendations) which takes approximately
10 1/4 hours. For some reason it took 12 hours and the bottom and middle
shelves, not surprisingly, over-fired. Lots of ruined pots, less than 2
weeks before a major sale (natch). And yes, I was guilty of leaving the
house during the firing. Yet when I double-checked to see if I had put in a
different program, the numbers were the same as always.'
Joan, I have agonizingly experienced the same thing...same ramp firing
schedule and terribly overfired pots.
My variable in this equation was not a new kiln, but a new thermocouple
installed in my Skutt 1027.
In several sacrificial/experimental firings with witness cones I discovered
that this new thermocouple was the culprit.
It was giving a different read on the computer controller from my previous
thermocouple.
I am now firing with about 70 F. lower temperature programmed into the
computer controller to get cone 9 like I used to.
Hope this helps.
Regards
Lee
Canyon Creek Pottery
Golden, B.C.
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Cynthia Bracker on tue 2 nov 04
Dave (Sturm, our kiln tech) & I concur with Ron Roy. Your top element
is probably dead or dying. Do the test Ron suggested, but remember the
top and bottom elements SHOULD glow before the middle four do because
they have a different resistance. Also, If the elements have just hit
the point where they're just starting to get tired, they will still
glow, it will just take a little longer. The most accurate way to test
your elements is to use an Ohm meter. Call Neal or Perry at Skutt (You
can also call here for Dave, but he's going to be gone most of the week,
so Skutt's your best bet) and give them the reading. (Remember to also
give them your kiln model number, voltage and phase also) They can tell
you whether you need new elements. Personally, I would advise you to
replace them ALL at the same time to maintain consistency of heat
throughout your kiln. Skutt elements are $41.00 each and there are 6 in
that kiln. Your local supplier may give you a discount of up to 10% off
so you're looking at around $250.00 with shipping and tax if you do it
yourself.
Good luck!
Cindy Bracker
Bracker's Good Earth Clays, inc.
joan woodward wrote:
>Lee responded kindly to my "firing gone wrong" post by telling me that the culprit in his case was a new thermocouple. Unfortunately, I don't have a new thermocouple, but maybe it's my old one?? I just emptied a 2-shelf bisque firing. I used an 05 cone firing mode which usually gives me an 05 1/2 to 06 firing. The temperature never got higher than 1879 F, the firing took about 15 minutes (at 06 in this case) but the bottom shelf fired to a full, touch the shelf 04! This is obviously not a tragedy in itself, but I can't have a 2 cone variation in my glaze firing. Any more ideas gratefully accepted! Three more glaze firings needed before my upcoming sale.
>
>Now I have two things to be nervous about: my kiln AND the election!
>
>Joan
>
>The Bedfords wrote:
>'Here's an experience new to me. I've got a Skutt 1027-3 computer
>controlled kiln. I fired it yesterday on the same ramp/hold schedule I
>always use (based on Ron & John's recommendations) which takes approximately
>10 1/4 hours. For some reason it took 12 hours and the bottom and middle
>shelves, not surprisingly, over-fired. Lots of ruined pots, less than 2
>weeks before a major sale (natch). And yes, I was guilty of leaving the
>house during the firing. Yet when I double-checked to see if I had put in a
>different program, the numbers were the same as always.'
>
>Joan, I have agonizingly experienced the same thing...same ramp firing
>schedule and terribly overfired pots.
>
>My variable in this equation was not a new kiln, but a new thermocouple
>installed in my Skutt 1027.
>In several sacrificial/experimental firings with witness cones I discovered
>that this new thermocouple was the culprit.
>It was giving a different read on the computer controller from my previous
>thermocouple.
>I am now firing with about 70 F. lower temperature programmed into the
>computer controller to get cone 9 like I used to.
>Hope this helps.
>
>Regards
>Lee
>
>Canyon Creek Pottery
>Golden, B.C.
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
>
>
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>Yahoo! Mail - You care about security. So do we.
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
>
>
>
>
joan woodward on mon 8 nov 04
To the many kind folks who helped me troubleshoot my over-firing kiln: you were all right. I replaced the thermocouple (unfortunately not the $15 repair as was indicated, but a $55 replacement since my kiln uses the old round thermocouples). That helped. Then my local clay supplier made an emergency house call with his OM (sp?) meter and checked my elements, which are deteriorating but not yet completely gone. Because I wasn't yet stressed enough over all of this, I started experiencing power failures too. Turns out my relays definitely need replacing. So now I'm having to babysit the kiln through each firing, staying out there nearly 11 hours to continually reprogram every time the power fails. But I lowered my temperature 10 degbrees and my hold from 20 to 10 minutes - and the glazes are now turning out beautifully. The last firing is happening now - and I need to get back to the studio! Just wanted to thank all of you for the your quick responses and report back.
Joan in Grand Junction, where it's been beautiful the past few days.
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Arnold Howard on mon 8 nov 04
Joan, most digital controllers turn back on automatically after a power
failure. They remain off only after an extended power failure. I suggest
that you check your controller manual for specific details. It may not be
necessary for you to sit with your kiln during the entire firing.
Sincerely,
Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
arnoldhoward@att.net / www.paragonweb.com
From: "joan woodward"
> Because I wasn't yet stressed enough over all of this, I started
> experiencing power failures too. Turns out my relays definitely need
> replacing. So now I'm having to babysit the kiln through each firing,
> staying out there nearly 11 hours to continually reprogram every time the
> power fails. But I lowered my temperature 10 degbrees and my hold from 20
> to 10 minutes - and the glazes are now turning out beautifully. The last
> firing is happening now - and I need to get back to the studio!
claybair on mon 8 nov 04
Joan,
Take this old dummy's advice.....
1. Don't nurse your tired old elements too long.
2. Don't plan on the elements lasting until you
fire work for holidays/major shows/big commissions
because Murphy's Law always kicks at that time.
Been there done that.... was only saved by a sweet
husband who changed elements while I was at a show.
Gayle Bair
Bainbridge Island, WA
http://claybair.com
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG]On Behalf Of joan
woodward
Sent: Monday, November 08, 2004 8:52 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: firing gone wrong
To the many kind folks who helped me troubleshoot my over-firing kiln: you
were all right. I replaced the thermocouple (unfortunately not the $15
repair as was indicated, but a $55 replacement since my kiln uses the old
round thermocouples). That helped. Then my local clay supplier made an
emergency house call with his OM (sp?) meter and checked my elements, which
are deteriorating but not yet completely gone. Because I wasn't yet
stressed enough over all of this, I started experiencing power failures too.
Turns out my relays definitely need replacing. So now I'm having to babysit
the kiln through each firing, staying out there nearly 11 hours to
continually reprogram every time the power fails. But I lowered my
temperature 10 degbrees and my hold from 20 to 10 minutes - and the glazes
are now turning out beautifully. The last firing is happening now - and I
need to get back to the studio! Just wanted to thank all of you for the
your quick responses and report back.
Joan in Grand Junction, where it's been beautiful the past few days.
---------------------------------
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Check out the new Yahoo! Front Page. www.yahoo.com
____________________________________________________________________________
__
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
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