[Clayart] Pyrometer, kiln venting
Carolyn Curran
mountaintops and valleys: In 50 years as a potter I have managed to avoid
coming in contact with pyrometers but am now in situation where one might
be desired or needed. At present the only kiln in my communal studio
which is connected to a vent is off limits to this independent
experienced potter, being used exclusively for communal studio teacher
supervised student work at cone 04.
There is, however, an older non computerized small doll kiln which I could
use for cone 6 firings if used in an outdoor situation with no need for
venting. Yeah, junior cones could be used for the test kiln as in the
olden days, but pyrometer might be better solution in this instance.
Are there any probes which have small enough diameter to fit in small test
kiln peephole?
I am always looking for alternative solutions to challenges here: The
studio has large unused older electric kiln which only needs venting.
Any bright ideas for non invasive venting solutions which engineering
department in this facility could use which would not involve a lot of
time ? Labor shortages here (and in so many facilities) have meant that
many non essential projects are shelved. This aging potter's needs are
unfortunately in the non essential category.
Hey, greetings of the holiday season to all Clay Arters. May winter
weather be kind to you and warm fuzzies abound. (Marcia Selsor's
Facebook page recently showed the first major winter snowblowing of the
season, so it's begun even before the solstice.)
Carolyn Curran
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William Schran
direct vent system that involves drilling a 1/4" or 3/8" hole through
the bottom section wall and the vent hose is attached at that location
on the kiln: https://www.baileypottery.com/m-405-010.html If you want
to exhaust from bottom of kiln you might but the under mount expansion
kit by Orton: https://www.baileypottery.com/m-405-010.html. The vent
motor can be mounted on a board that could be installed in an existing
window.
Check Clay King for pyrometers & thermocouples:
https://www.clay-king.com/pyrometer.htm
William Schran...@twc.com703-505-1617
-----------------------------------------From: "Carolyn Curran"
To: "Carolyn Curran"
Cc:
Sent: Tuesday December 7 2021 8:49:00PM
Subject: [Clayart] Pyrometer, kiln venting
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David Woof
Firing by pyrometer is as inaccurate a way to measure actual heat work as is firing by trusting your Kiln sitter.
While one can use cones to "dial in" the Pyrometer, or Kiln Sitter, both will again drift over time and diminish accuracy unless you "dial in" again, and later again.
I simply use Pyrometers to indicate and alert me as to when the kiln is approaching the temperature to pay close attention to the pyrometric cone pac one watches thru the peep hole.
The pyrometric cone pac is the only true indicator of the Heat Work accomplished in the clay and glazes, and therefore, the only way to achieve consistent firing results firing to firing.
The interior end of the peep hole (using a pen knife) can be slightly enlarged to give an increased cone shaped viewing scope to see the cones better. A "Mini Mag Light" (buy the name brand) costs $20.00 US or so, and has enough Lumens to illuminate and cause the cones to visibly stand out at maturing temperature.
No deleterious consequences for enlarging the peep hole unless you get caught, or brag to someone that you did it. (Haaa) Brush out or vacuum the dust and chips!!!
Don't let your light shine in Enemy territory!!!
Misneach,
David Woof.............................................................................................
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________________________________
From: Clayart <clayart...@lists.clayartworld.com> on behalf of Carolyn Curran <cncp...@gmail.com>
Sent: Tuesday, December 7, 2021 8:51 AM
To: cla...@lists.clayartworld.com <cla...@lists.clayartworld.com>; Carolyn Curran <cncp...@gmail.com>
Robert Harris
while I certainly fire by cones in our big gas kiln, I have found that the
MODERN pyrometers and thermocouples that we use in addition to cones a)
don't drift (at least not that I've noticed) and b) are probably just as
accurate than cones when taking into account whether the kiln is turned off
when Cone 10 is at 3:00, just touching, or flat, or if the pack is just a
little too close to the peeps (cold spot). Certainly firing by pyrometer
would be less than half a cone difference between firing, which is less
than the difference between the top middle (usually hits cone 11 @ 2 or 3)
and the bottom front of the kiln (Cone 10 @ 2:00).
After more than 250 glaze firings in a computer controlled electric kiln I
notice absolutely no difference in the glazes. (There were a couple of
firings in a row when the thermocouple obviously needed to be replaced, but
as far as I could tell it went from fine to catastrophic failure).
And honestly I sometimes think that we get too hung up on exactitude.
Measuring glazes by volume (as many old potters did) introduces far more
difference in a glaze than firing by a modern pyrometer.
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David Woof
Woof sez: I too know what you and Mel know..bla bla.... but sometimes here on Clayart folks jump at the chance to tell what they know while missing the expressed wishes of what the original person was asking for.
If you read what Carolyn was asking for you would realize that I was writing a conservative response to an expressed specific need and circumstance for Carolyn.
So please consider this before your knees start jerking or you tear ligaments while attempting to pat between your scapula.
Love conquers all,
Your very own Woofster..............................................................................................................
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________________________________
From: Clayart <clayart...@lists.clayartworld.com> on behalf of Robert Harris <robert...@gmail.com>
Sent: Wednesday, December 8, 2021 7:59 PM
To: Clayart international pottery discussion forum <cla...@lists.clayartworld.com>
Subject: Re: [Clayart] Pyrometer, kiln venting
Robert Harris
be afraid to fire with whatever you can get your hands on.
If you can't see the cones (I've never been able to successfully see cones
in an electric kiln with 3 1/2" brick - and I'm not a big fan of carving
them out), use a pyrometer. The number on the pyrometer may not be exactly
equivalent to the numbers on the cone chart, but it'll be the same every
time, and as long as you ramp the same, the firing will be consistent.
If you don't have a pyrometer, use the Infra-red temp gun Mel talks about
(tip - put a pot or stilt 3 inches in from the peep and aim the gun at
that. It needs an object to measure the heat of). Again the numbers may not
be exactly the same, but it will be consistent. You may have to alter what
temp you aim for, depending on your glazes, but once you've got it dialed
in ... no problem.
Or finally, do it the old fashioned way by temperature colour. Bad for your
eyes, and very inaccurate but if you make sure your glazes mature (and
don't overfire) over a wide temperature range, this won't matter.
As with everything: don't get hung up on whether us Yahoos on the internet
say it can or can't be done. Try it. Troubleshoot, and try it again!
As long as the clay and glazes are fully mature (and even that only matters
for functional stuff), it doesn't matter a damn how you got there!
Robert
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Robert Harris
are plenty of ways to skin a cat.
And also specifically pointing out that your implication that Kiln sitters
and pyrometers aren't good enough is total bullshit. For a start handmade
ceramic glazes never need to be that accurate and moreover when industry,
particularly in high tech ceramics, which needs far more accuracy than
you've ever used, fire their kilns what do they use ... pyrometers NOT
cones!
Personally I can never see the damn cones in an electric kiln, and I have
no desire to excavate any part of the kiln wall, which is a) there for a
reason and b) irreversible.
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David Woof
***From My previous post: "Woof sez: I too know what you (Robert) and Mel know..bla bla.... but sometimes here on Clayart folks jump at the chance to tell what they know while missing the expressed wishes of what the original person was asking for.
If you read what Carolyn was asking for you would realize that I was writing a conservative response to an expressed specific need and circumstance for Carolyn."
________________________________
From: Clayart <clayart...@lists.clayartworld.com> on behalf of Robert Harris <robert...@gmail.com>
Subject: Re: [Clayart] Pyrometer, kiln venting
are plenty of ways to skin a cat.
And also specifically pointing out that your implication that Kiln sitters
and pyrometers aren't good enough is total bullshit. For a start handmade
ceramic glazes never need to be that accurate and moreover when industry,
particularly in high tech ceramics, which needs far more accuracy than
you've ever used, fire their kilns what do they use ... pyrometers NOT
cones!
Personally I can never see the damn cones in an electric kiln, and I have
no desire to excavate any part of the kiln wall, which is a) there for a
reason and b) irreversible.