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Cold Kiln

Posted: Wed Jan 07, 2004 4:17 pm
by PDXBarbara
This one's for all you wise ovenheds out there in WG-land...

It's cold here in Portland. Right now it's hovering around freezing, and yesterday & overnight it was colder. When I said goodnight to my Skutt coffin Monday at about 3 pm, the controller was blinking 33 degrees.

Does this cold affect my kiln? elements? controller? If I need to fuse, what precautions to take in the schedule? Must I warm it up first or anything?

Thanks, all.
Barbara

Posted: Wed Jan 07, 2004 4:37 pm
by Carol
I hope not. This past week I've done 2 firings starting from 33 degrees and one starting from 29 degrees using a standard schedule.

Carol

Re: Cold Kiln

Posted: Wed Jan 07, 2004 4:57 pm
by jim simmons
PDXBarbara (Bader) wrote:This one's for all you wise ovenheds out there in WG-land...

It's cold here in Portland. Right now it's hovering around freezing, and yesterday & overnight it was colder. When I said goodnight to my Skutt coffin Monday at about 3 pm, the controller was blinking 33 degrees.

Does this cold affect my kiln? elements? controller? If I need to fuse, what precautions to take in the schedule? Must I warm it up first or anything?

Thanks, all.
Barbara
Hi My Daughter, :)

In order.
no
no
no
none
no

Jim

Posted: Wed Jan 07, 2004 5:12 pm
by Bev Brandt
Don't know abouit the kiln brick and elements, but I just got off the phone with my husband the ex-electrical engineer. He was a reliability engineer for a defense contractor in his previous life and he used to test electronic components.

He said (in many words) not to worry about low temperatures in regards to your controller. In fact, he said that the worst thing that could happen is that the controller's electronics simply wouldn't work at low temps, then they *would* work if the temperature got higher.

Your controller handbook should tell you the minimum and maximum operating temps for the controller. Mine says not to operate the controller at more than 120F. Higher temperatures are more damaging, apparently.

Also, in the many words hubby said, it seems that environmental issues like ambient temp would do harm to the electronics over time AND only if low and high temperatures were reached quickly AND then if cracks happen or dirt/moisture gets into certain parts. So today's 33F *might* only make a very small contribution to a failure 20 years from now. (Or never, Mean Time Between Failures is just a shot in the dark anyway!)

Mr. BSEE Brandt has also said in the past "if it's gonna fail, it'll do it within about 30 days." My experience in IT has been just that. :roll: And Mr. BSEE has said that commercial electronics come off the same assembly line as military-spec'd electronics and that the quality is probably just as good.

"Mil-Spec" says that circuits must operate at something like -100F. Or is that C? Who knows...it's darned cold, though.

- Bev

Re: Cold Kiln

Posted: Wed Jan 07, 2004 5:18 pm
by PDXBarbara
jim simmons wrote:
PDXBarbara (Bader) wrote:This one's for all you wise ovenheds out there in WG-land...

It's cold here in Portland. Right now it's hovering around freezing, and yesterday & overnight it was colder. When I said goodnight to my Skutt coffin Monday at about 3 pm, the controller was blinking 33 degrees.

Does this cold affect my kiln? elements? controller? If I need to fuse, what precautions to take in the schedule? Must I warm it up first or anything?

Thanks, all.
Barbara
Hi My Daughter, :)

In order.
no
no
no
none
no

Jim
Ahhhhsoooooo. Merci, m'lord....
yer ever-so-humble servant,
PDXFebruary

Posted: Wed Jan 07, 2004 5:20 pm
by PDXBarbara
Bev Brandt wrote:
He said (in many words) not to worry about low temperatures in regards to your controller.
Thanks, Bev & hubby... I interpret your hubbie's remarks to match Jim Simmons' above....
NoMoreFearinPDXgirl

Posted: Wed Jan 07, 2004 7:06 pm
by Carol B
Hi Barbara,

I wrote Skutt with that same question a few weeks ago. I was informed that the only concern is the controller and that I was advised not to run the kiln below 32 degrees.

Carol

Posted: Wed Jan 07, 2004 7:10 pm
by PDXBarbara
CarolB wrote:Hi Barbara,

I wrote Skutt with that same question a few weeks ago. I was informed that the only concern is the controller and that I was advised not to run the kiln below 32 degrees.

Carol
ah HA!
bb

Posted: Wed Jan 07, 2004 9:31 pm
by Tony Smith
Because of the way the controller is designed, I don't believe it will register negative numbers, and the controller will give an error message (and not run).

Tony

Posted: Wed Jan 07, 2004 10:01 pm
by Cynthia
My kilns are in the garage. We get overnight temps in the teens and even on several nights a season will get below zero but the garage retains a little warmth. I have started up the kilns when they read in the twenties and all has been well.

They tend to cool to room temp at near the same rate too...so I don't add a ramp to slow that down for regular thickness (6mm) firings.

Posted: Thu Jan 08, 2004 12:27 am
by Kevin Midgley
The danger of running cold kilns is not the cold so much as condensation that can form on the controller circuitry that could possibly cause a malfunction. Kevin in Tofino.

Posted: Thu Jan 08, 2004 12:48 am
by PDXBarbara
Tony Smith wrote:Because of the way the controller is designed, I don't believe it will register negative numbers, and the controller will give an error message (and not run).

Tony
ah HA!

Posted: Thu Jan 08, 2004 12:49 am
by PDXBarbara
Cynthia wrote:My kilns are in the garage. We get overnight temps in the teens and even on several nights a season will get below zero but the garage retains a little warmth. I have started up the kilns when they read in the twenties and all has been well.

They tend to cool to room temp at near the same rate too...so I don't add a ramp to slow that down for regular thickness (6mm) firings.
ah HA!

Posted: Thu Jan 08, 2004 12:51 am
by PDXBarbara
Kevin Midgley wrote:The danger of running cold kilns is not the cold so much as condensation that can form on the controller circuitry that could possibly cause a malfunction. Kevin in Tofino.
ah HAAA!

Re: Cold Kiln

Posted: Thu Jan 08, 2004 5:43 am
by Brian and Jenny Blanthorn
PDXBarbara (Bader) wrote:This one's for all you wise ovenheds out there in WG-land...

It's cold here in Portland. Right now it's hovering around freezing, and yesterday & overnight it was colder. When I said goodnight to my Skutt coffin Monday at about 3 pm, the controller was blinking 33 degrees.

Does this cold affect my kiln? elements? controller? If I need to fuse, what precautions to take in the schedule? Must I warm it up first or anything?

Thanks, all.
Barbara
When cold my controler gives me error message

I sit with kiln a few mins as temp warms up ( elements on )

Then controler works Ok

B4 that with error mesage kiln is on full so I manually turn on + off

Brian

All you weather wimps!

Posted: Thu Jan 08, 2004 12:23 pm
by Andrew
I gotta laugh.

My kilns are in my garage.

It was 9 BELOW zero Fahrenheit (for you non-celsius junkies out there) the night before last.

I've not had a problem, in fact it is kinda nice keeping the garage somewhat warm and making glass at the same time.

Andrew in Minnesota

Posted: Thu Jan 08, 2004 1:00 pm
by BobB
A good rule of thumb might be to warm your shop before you fire AFAP to 1000. It can't be good for the life of your elements to slam power to them and heat them up from really cold to steamin! Correct me if I'm wrong but an element (coil of wire) is similiar to a light bulb filament. What burns a light bulb out faster if you flick it on and off allowing it to cool and heat up real fast, stressing the wire and it breaks. Elements will be stressed also in the same manner.

Condensation inside the controller is another issue and can cause problems long term. If your shop get cold enough to have condensation in your controller then you probably have it in your saw, grinder and sander motors.

If your shop gets really cold at night you might consider a small heating duct off you house heat to at least keep it above freezing.

Warm in Texas BobB

Posted: Thu Jan 08, 2004 3:20 pm
by Bert Weiss
BobB wrote:A good rule of thumb might be to warm your shop before you fire AFAP to 1000. It can't be good for the life of your elements to slam power to them and heat them up from really cold to steamin! Correct me if I'm wrong but an element (coil of wire) is similiar to a light bulb filament. What burns a light bulb out faster if you flick it on and off allowing it to cool and heat up real fast, stressing the wire and it breaks. Elements will be stressed also in the same manner.

Condensation inside the controller is another issue and can cause problems long term. If your shop get cold enough to have condensation in your controller then you probably have it in your saw, grinder and sander motors.

If your shop gets really cold at night you might consider a small heating duct off you house heat to at least keep it above freezing.

Warm in Texas BobB
I have worked for many years in a cold climate with various degrees of auxillary heat, from none to some.

I have never experienced a problem!! I am curious to know what the controller would read at below zero. I guess I never noticed that.

The difference between 10º F and 50ºF is negligable when you consider that the element wires can handle 1700º. The same goes for cooling.

The only problem I ever had working in a cold shop was when the glass cleaner froze to the glass so I couldn't clean it before cutting. Other than that, everything works.

BTW this year I have a propane heater on a thermostat set to 50. What a luxury!! That's because my corn burning stove quit working in the cold snap last winter so I bit the bullett and bought a heater that didn't require human interaction.

Posted: Fri Jan 09, 2004 12:01 am
by PDXBarbara
Bert Weiss wrote: when the glass cleaner froze to the glass so I couldn't clean it before cutting. .
eeeeek. imagining a tongue stuck there.... eeeeeek.
bb

Posted: Fri Jan 09, 2004 10:46 am
by Bert Weiss
PDXBarbara (Bader) wrote:
Bert Weiss wrote: when the glass cleaner froze to the glass so I couldn't clean it before cutting. .
eeeeek. imagining a tongue stuck there.... eeeeeek.
bb
I never tried that.

This is one of those mornings. The TV news said that it was 24 below here, but on my porch the thermometer only read 8 below 0.