Fusing/slumping/casting with kiln sitter

Dec 01, 2003 14 Replies

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


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

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 (½") 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:

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.

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

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

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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

I would love to see a pic. Jack

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the 8.4 meter mirror in tucson az was annealed in about 3 months.

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for the casting info
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for the complete set ofpicture and movie links.regards, charlie cave creek, az

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

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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

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

snipped-for-privacy@xmission.com

Jack

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Just a qick question Jack. what are the elents you are using in the kiln you show in your photos?

Best regards, Charles

I'll assume you mean elements here. I got mine from Dudley Giberson at

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helped build a crucible furnace during the summer and we wound our ownelements from Kanthal wire.

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