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rant: meltdowns, overfiring,

updated tue 7 dec 04

 

pdp1@EARTHLINK.NET on tue 30 nov 04

and other electric catastrophes

Hi Arnold,



At least on a Kiln, you have a lot of 'Bill Board' room to
have something written boldly...

You know, something like one of those euro-new-speak 'signs'
as have a big "X" over a line-vignette of someone leaving
their Kiln un-attended...of someone walking "away" from
it...

Or a good old USA sort of admonishion, like "STOP! - READ
THIS !!!!" - "Do NOT leave your Kiln un-attended when
Fireing!" - In Big Old three-inch-high Banner Headline
letters...with the word 'not'...in Italic...

Actually, that one would read really good, maybe best of
all...in German...


Might just do the trick!


Best wishes,


Phil
el ve

----- Original Message -----
From: "Arnold Howard"


> Kiln manufacturers love messages like this one from John
and Wayne. We all
> warn against over-fires in our instruction manuals, but I
think some people
> ignore the warning. Maybe they assume that it is only a
legal disclaimer.
>
> Sincerely,

Arnold Howard on tue 30 nov 04

and other electric catastrophes

Industrial kilns have the "overtemp" alarm system Rick mentioned. It is a
separate digital controller and thermocouple wired to a bell and flashing
light.

By the way, I have never heard of a fire caused by an over-fired electric
kiln. Has anyone else? I examined a kiln one time that had been in a garage
fire, but we determined that the kiln hadn't even been on when the fire
started. I'm sure other fires have been caused by flammable materials near
the kiln.

Ordinarily, when a kiln over-fires, the elements burn out because they get
too hot. Then the kiln cools down on its own. The intense heat is confined
to the firing chamber.

Sincerely,

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

From:
> Maybe the best thing to do is to buy a digital pyrometer that has an alarm
> feature for a preset temp. I have seen these made by a number of
> manufacturers but never offered in the pottery supply catalogs. They are
> costly, but so is a lost load or a fire.
> Rick

Arnold Howard on tue 30 nov 04

and other electric catastrophes

Kiln manufacturers love messages like this one from John and Wayne. We all
warn against over-fires in our instruction manuals, but I think some people
ignore the warning. Maybe they assume that it is only a legal disclaimer.

Sincerely,

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

From: "John Hesselberth"
> Wayne's message, part of which I have reproduced below, is one of the
> most important and bluntly stated that has appeared on Clayart in some
> time. Please heed it. If you don't have time to monitor your kiln while
> it is firing, find another hobby--and I use the word hobby
> purposefully. No professional potter, in my opinion, would leave an
> unmonitored kiln. Too many things can go wrong.
>
> Regards,
>
> John
>>
>> Or move your wheel within viewing distance, and throw while you
>> fire, or handbuild. Just BE there!
>>
>> No time to watch the kiln you say? Too busy doing other important
>> things that your life is full of? Would you leave a pot burning on
>> the stove? A turkey in the oven "oh it will be fine"?
>>
>> If you haven't time to watch the kiln, be there while it's firing
>> start to finish, then you haven't the time to "do" pottery.
>>
>> Find another hobby. One that won't eventually burn your house down
>> and ruin your life, the lives of your family and neighbors, kill
>> your pets.

John Rodgers on wed 1 dec 04

and other electric catastrophes

Arnaold, my new Paragon TnF has an instruction plate on the front of it
that very plainly says "Do not leave unattended when in operation!"

I don't know how much plainer the message can be put.

BTW, love that kiln!!

John Rodgers
Chelsea, AL

Arnold Howard wrote:

> Kiln manufacturers love messages like this one from John and Wayne. We
> all
> warn against over-fires in our instruction manuals, but I think some
> people
> ignore the warning. Maybe they assume that it is only a legal disclaimer.
>
> Sincerely,
>
> Arnold Howard
> Paragon Industries, L.P., Mesquite, Texas USA
> arnoldhoward@att.net / www.paragonweb.com
>
> From: "John Hesselberth"
>
>> Wayne's message, part of which I have reproduced below, is one of the
>> most important and bluntly stated that has appeared on Clayart in some
>> time. Please heed it. If you don't have time to monitor your kiln while
>> it is firing, find another hobby--and I use the word hobby
>> purposefully. No professional potter, in my opinion, would leave an
>> unmonitored kiln. Too many things can go wrong.
>>
>> Regards,
>>
>> John
>>
>>>
>>> Or move your wheel within viewing distance, and throw while you
>>> fire, or handbuild. Just BE there!
>>>
>>> No time to watch the kiln you say? Too busy doing other important
>>> things that your life is full of? Would you leave a pot burning on
>>> the stove? A turkey in the oven "oh it will be fine"?
>>>
>>> If you haven't time to watch the kiln, be there while it's firing
>>> start to finish, then you haven't the time to "do" pottery.
>>>
>>> Find another hobby. One that won't eventually burn your house down
>>> and ruin your life, the lives of your family and neighbors, kill
>>> your pets.
>>
>
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>
>

katetiler on fri 3 dec 04

and other electric catastrophes - Long!

Overall I agree with what Kim has said about this - whether this is
because in the UK we tend to use a different firing regime with our
electric kilns & not use 'sitter bars'?

I run two kilns, both electric, one small, just over a foot square
inside, the other a larger round top loading about 2.5 times the size,
and I fire both to earthenware temperatures using an electronic
controler that I unplug & swap between them, both are fitted with a
pyrometer. They are located outside in my (wooden) workshop, running
off a seperate junction box with a fuse equivalent to a normal
domestic cooker. I had the electricity wired up professionally when we
mooved here, but they really are no more complex than a standard cooker.

The only time I ever had any problems was with my old controller,
which was a little 'Heath Robinson' style with dials that I had to
turn manually to increase the % electric flow, to increase the heat
during the firing cycle, i.e 10% at first for an hour to drive off the
steam, then 25%, 60%, up to 100% for continuous firing when I was
ready to ramp up. The old box used to see me padding across in my
slippers at 3am, 6am etc from the house in order to increase the heat,
then the pyrometer would cut off the power when the final temperature
was reached.

The old box failed when I realised that instead of the 'clunk pause
clunk' that I'm used to hearing during the first 10% cycle, all I
could hear was the faint hum of the 100% firing - so I switched it off
at the wall & got a kiln engineer in, ended up buying a new controller.

I think having that old box did me a favour though - if I'd always
used my posh electronic digital controller I may have just stuck to
the pre-set programs from not being confident.

Anyway - I have not got the time or inclination to sit out in my
workshop all night in my slippers while my kiln fires, and the point
to this ramble is - what about the corrosive fumes that are given off
during glaze firing?

I've known old pottery windows that look like frosted glass due to
years of corrosion from glaze fumes - that can't be healthy to sit &
breath in while worrying about your kiln overfiring?

Also the first thing I did when I took my kiln home was to go aout &
buy a proper (large) fire extinguisher to use on electrical fires, I
keep it by the door. Better safe than sorry :)

Kate

Rod Wuetherick on sat 4 dec 04

and other electric catastrophes - Long!

What we have done at out studio is simply buy an intermatic 12 hour timer -
mounted on the wall in the kiln room and wired it to a fairly loud bell.
Even if Waylon, Willie or some Rock and Roll is playing loud we can hear it.
As well I have run wires out of each kiln in the kiln room that lights a
small 20W red light above the kiln room door which shows if a kiln is on.
The fan for the kiln room is also on an intermatic 12 hour timer and it as
well has a light to how that it is indeed on as well.

Some may call all of this overkill I call it peace of mind.

Peace,
Rod

RR Said ....

There is no reason that a system cannot be implemented that would remind
some one to check the kiln - especially at crucial times.

......

RR

Ron Roy on sat 4 dec 04

and other electric catastrophes - Long!

Hi Kate,

I have been stewing about this as well - I certainly would not advise
anyone to stay in the same room watching a kiln fire unless there was very
good ventilation. That means either too hot or too cold in my world.

There is no reason that a system cannot be implemented that would remind
some one to check the kiln - especially at crucial times.

I carry a kitchen timer around with me - set to remind me to check the
firing at whatever time I set it for. Remembering to re set it becomes the
main problem.

I also have a red light wired into the main breaker for the kiln - when the
breaker is on the red light is on - hard to ignore a red light.

Surely we are all creative enough to figure out a system to remind us that
a kiln is firing - based on our own particular idiosyncrasies.

RR


>Anyway - I have not got the time or inclination to sit out in my
>workshop all night in my slippers while my kiln fires, and the point
>to this ramble is - what about the corrosive fumes that are given off
>during glaze firing?
>
>I've known old pottery windows that look like frosted glass due to
>years of corrosion from glaze fumes - that can't be healthy to sit &
>breath in while worrying about your kiln overfiring?
>
>Also the first thing I did when I took my kiln home was to go aout &
>buy a proper (large) fire extinguisher to use on electrical fires, I
>keep it by the door. Better safe than sorry :)
>
>Kate

Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513

John Rodgers on sun 5 dec 04

and other electric catastrophes - Long!

John Hesselberth wrote:

> I
> would rather see people set the kiln to start in the middle of the
> night so it is approaching red heat when they arrive in the morning
> than vice versa. That way it is at fairly low temperatures when
> unattended. But this isn't a very good practice either, in my opinion,
> unless you are physically present on the site for the entire firing.


John,

Kiln start up in the middle of the night is a fairly easy thing.

Computer controlled kilns should be able to be set to start at whatever
time one might wish. Also for those without computers, there are timers
that will turn on the power for a standard kiln, thus allowing the kiln
to initiate firing at most any time of night you might specify.

I worked for fair sized ceramic manufacturer in the west, and we fired a
big gas kiln plus numerous electric kilns. The gas flow to the burners
was controlled by a timer. WE would set the pilot lits "ON" and then set
the timer so the main flow valve would open at the specified time. The
pilots would "candle" the kiln all night, up to 1200F, then at 4 am the
main gas valve would open and the burners would kick in. This gave an
early enought start that the firing could be finished before work ended
in the afternoon. Worked really well.

Also, we used timers on our big 500 gallon slip mixing tanks. They would
turn on in the wee hours of the morning and the slip would be ready by
the time we got there to start casting for the day.

Timers are great.

John Rodgers

Chelsea, AL

John Hesselberth on sun 5 dec 04

and other electric catastrophes - Long!

On Saturday, December 4, 2004, at 02:01 PM, Ron Roy wrote:

> I have been stewing about this as well - I certainly would not advise
> anyone to stay in the same room watching a kiln fire unless there was
> very
> good ventilation. That means either too hot or too cold in my world.
>
> There is no reason that a system cannot be implemented that would
> remind
> some one to check the kiln - especially at crucial times.

I would certainly agree with this approach. I am not in the room at all
times and don't think it is necessary. But I don't leave the house when
the kiln is firing and I check it frequently when it gets above red
heat. I am always close at hand when maturity is approaching.

What really bothers me--and I know this happens every day because I
have had a lot of people tell me they operate this way--is when an art
teacher starts the kiln at the end of the school day and depends on the
kiln sitter or computer to turn it off in the middle of the night. I
know this is a particularly difficult situation for a teacher to manage
because, if the kiln is right in their classroom, they don't want
themselves or their students to be exposed to the fumes. My only
suggestion to to move the kiln to another space outside the classroom
that is well ventilated so you can fire during the school day or start
coming in on weekends to fire--or decide you really can't have a
ceramics program in your school until you get proper facilities. I
would rather see people set the kiln to start in the middle of the
night so it is approaching red heat when they arrive in the morning
than vice versa. That way it is at fairly low temperatures when
unattended. But this isn't a very good practice either, in my opinion,
unless you are physically present on the site for the entire firing.

On the other hand, on the bright side, this technique of firing into
the night unattended did give me a ready market for an extra kiln I had
a few years back when a local potter/art teacher melted one down beyond
repair. I've forgotten the exact sequence of events, but a power
failure of a couple hours duration was involved. Wish I could remember
how that caused or aggravated the problem.

Regards,

John

John Hesselberth
http://www.frogpondpottery.com
http://www.masteringglazes.com