Fusing/slumping/casting with kiln sitter

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I've done a little bit of kilnwork before, but have never managed to get
access to a kiln regularly. A friend has offered me a loan of her ceramics
kiln (she mainly fires tiles) fitted with a kiln sitter.

I appreciate that this isn't the ideal method of learning, but at present
the possibility of regular kiln access is tempting. Is anyone using a kiln
sitter set up to fuse/slump/cast glass? I'm happy to experiment, and can be
in attendance while I fire, but a few initial pointers would be great? I'll
gladly post my results/progress for anyone in a similar position...

Gordon Watt
morningglass



Re: Fusing/slumping/casting with kiln sitter
you need to wedge the sitter open, (not use it), get a pyrometer and a plug
with a hole the size of the pyrometer to be able to have it in the kiln.
This may run a hundred bucks or so. After you get completely addicted you
will need a controller to plug the kiln into which will go 300 $$ or so.This
will eliminate the need for human tampering with on/off switches.  m


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be
I'll



Re: Fusing/slumping/casting with kiln sitter
Kiln sitters are not used here (Finland). As I understand it,
a kiln sitter is an emergency switch that prevents the kiln from
melting down. As such it is useful. You can set it to
trigger somewhere around 900 - 1000 C (1700-1850 F).

It may be used also to set a top temperature, where the kiln turns off.
I doubt it is accurate enough for glass work.

As long as you work under 6mm (") thickness, the natural cooling
of a ceramic kiln works well. When your ambition goes
to 1-2" thikness you need a three men crew to monitor
the annealing days and nights.

-lauri

Michele Blank wrote:

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Re: Fusing/slumping/casting with kiln sitter
  No, a kiln sitter is a device that uses an accurately made Orton Cone to
control a pottery kiln.  The cone (as in Cone 6 or Cone 10) reacts to heat
in the way the pottery does, so long slow heat or quicker fast rising heat
produce the desired results.   With pottery, it is safe to run the temp up
and when the cone trips, the kiln can shut off and coast back down.
   You are correct that it is not proper for glass.  It is not literally
measuring temp, but heat gain.   And letting the kiln crash may produce okay
results with thin glass, but with thicker glass, annealing will not occur
and the glass may shatter in the kiln or later.

--
Mike Firth
   Hot Glass Bits Furnace Working Website
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Re: Fusing/slumping/casting with kiln sitter
I HAVE used a kiln sitter successfully for both Slumping and fusing.
Why?  I have one and can't afford better.
It is true that they only control the Max temp, but they are very
accurate. Usually within a degree or so. (Just because a digital
readout displays an exact number doesn't mean its an accurate one.
When I kids were younger, I took to deliberately setting the digital
clocks wrong just to teach them this.)
you do need to pay particular attention to placing the cone to achieve
this accuracy. As for controlling ramping, Trial and error taught me
the switch settings to use and the time to run them. I use a kitchen
tiem to remind me when next to check things, and a K probe connected
to a DVM via an adapter to check actual temps in the Kiln
To control the soak, I bypass the sitter after its tripped and watch
it like a hawk. The final ramp down I have to rely on the natural
characters of the kiln, assisted by extra insulation.

wrote:

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Re: Fusing/slumping/casting with kiln sitter
On Sat, 06 Dec 2003 21:14:41 +1100, Greg Kraushaar

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And hope that the cone doesn't stick and over fire the kiln.
Just completed a glass cast 11KG  which took 13  1/2 days kiln time.

I use a Perfect Fire III and I love it

Cheers
Jo

Re: Fusing/slumping/casting with kiln sitter
On Tue, 09 Dec 2003 19:00:07 GMT, snipped-for-privacy@hotmail.com wrote:

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13-1/2 days. That's getting serious. The 200" mirror for the scope on
Mt Polomar took 11 months to cool. Josh Simpson's 12" diameter
"worlds" take about 4  months.

What were the dimensions of your casting?




Jack


    http://photos.yahoo.com/bc/xmissionbobo /


Re: Fusing/slumping/casting with kiln sitter

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Hi Jack

The diameter is just over 10 inch and 8 inch high , the weight is 11
KG or 24 Lbs  , the wall is just over 1 inch thick.
I could mail you a pic if you like

Cheers
Jo

Re: Fusing/slumping/casting with kiln sitter
On Wed, 10 Dec 2003 09:50:09 GMT, snipped-for-privacy@hotmail.com wrote:

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I would love to see a pic.
Jack


    http://photos.yahoo.com/bc/xmissionbobo /


Re: Fusing/slumping/casting with kiln sitter

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Hi Jack


Sorry but I can't find a email address on your site.

But I love the work you do specially those pendants they look very
good , I saw that effect in Singapore some time ago , I have not seen
that here in New Zealand , but then you don't se much here anyway.


Cheers

Jo



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Re: Fusing/slumping/casting with kiln sitter
On Wed, 10 Dec 2003 19:05:58 GMT, snipped-for-privacy@hotmail.com wrote:

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Thank you for the kind words. My email address should be on my posts
but just in case...

snipped-for-privacy@xmission.com

Jack


    http://photos.yahoo.com/bc/xmissionbobo /


Re: Fusing/slumping/casting with kiln sitter
Just a qick question Jack.  what are the elents you are using in the kiln
you show in your photos?

Best regards,
Charles


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Re: Fusing/slumping/casting with kiln sitter
"Charles A. Peavey" wrote:
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I'll assume you mean elements here. I got mine from Dudley Giberson at

http://www.joppaglass.com /

I helped build a crucible furnace during the summer and we wound our own
elements from Kanthal wire.
--
Jack


    http://photos.yahoo.com/bc/xmissionbobo /

Re: Fusing/slumping/casting with kiln sitter
the 8.4 meter mirror in tucson az was annealed in about 3 months.

http://medusa.as.arizona.edu/mlab/mlmail2.html for the casting info
http://medusa.as.arizona.edu/mlab/lbtcast2.html for the complete set of
picture and movie links.

regards,
charlie
cave creek, az

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Re: Fusing/slumping/casting with kiln sitter
On Wed, 10 Dec 2003 10:56:47 -0700, "Charles Spitzer"

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Great links, Charlie. Some good reading for tonight. I spent a day
touring Kitt Peak. Lots of fun. Never been to the Safford area but it
looks like an area worth seeing.



Jack


    http://photos.yahoo.com/bc/xmissionbobo /


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