Gas kiln for casting

[bouchette&wickart]

We'd like to build a gas-fired kiln for open-face casting of 2'x3'x2" pieces. Any references on gas-fired kiln design for glass? We have all the ceramic design references.

Thanks...
Deb & Prune in Oregon

[Bert Weiss]

We'd like to build a gas-fired kiln for open-face casting of 2'x3'x2" pieces. Any references on gas-fired kiln design for glass? We have all the ceramic design references.

Thanks...
Deb & Prune in Oregon

Deb & Prune


Gas kilns are very expensive to build and inexpensive to operate. I have never heard of a single gas kiln designed for casting. If you have access to electric power, I suggest that you go with the practiced medium.

Casting kilns have elements on all 6 surfaces.

[Brad Walker]

The main gas-fired kilns I'm aware of that are used for glass are used for firing glass paints and enamels on one layer of glass, not for casting. These can fire a single layer to 1200 very quickly (under 10 minutes), but I'm not sure they heat evenly enough to do casting and fusing on items thicker than about 1/4". The most common brand is Hoaf Speed Burn, made in the Netherlands. They cost $3000 to $10,000. http://www.hoaf.nl/ They're also carried by one of my sponsors -- click on Fusion HQ/HGH at top of the page.

The issue with gas has to do with even-ness of heating. Electric does a better job of heating glass evenly, especially with larger items. That doesn't mean that it wouldn't be possible to do this with gas, but it does mean that it would be difficult and would require some engineering expertise to ensure even-ness of heating throughout the kiln.

[watershed]

The other issue with gas, is temp control. There are digtal conrtoller for gas, on the market, but once you start going there, it gets almost as expensive as electric.

Though with my huge ego, and clay experience, I keep thinking I could build one. Bag walls, downdraft, you can hear the gears clashing from there.

Greg

[bouchette&wickart]

So, I have a Skutt 1227 electric w/controller and a Paragon GL24AD w/controller, but I want a larger kiln for flat work.
I also have a large propane-fired gas kiln (for ceramics) that I designed and built myself, and it's very even. I have pyrometers, but no auto controller.

It would seem to me that building a "saggar" chamber for the glass would encourage much more even heating of a large mess of glass.

My idea is to build the chamber with insulated brick, and center the chamber in the gas kiln, with good combustion space all around (including underneath). Then put a pyrometer in that goes inside the chamber, as well as one that checks the temp in the gas combustion area. Any more thoughts?

deb & prune

[Bert Weiss]

So, I have a Skutt 1227 electric w/controller and a Paragon GL24AD w/controller, but I want a larger kiln for flat work.
I also have a large propane-fired gas kiln (for ceramics) that I designed and built myself, and it's very even. I have pyrometers, but no auto controller.

It would seem to me that building a "saggar" chamber for the glass would encourage much more even heating of a large mess of glass.

My idea is to build the chamber with insulated brick, and center the chamber in the gas kiln, with good combustion space all around (including underneath). Then put a pyrometer in that goes inside the chamber, as well as one that checks the temp in the gas combustion area. Any more thoughts?

deb & prune

It really depends on how thick you plan to work. If you want to do long anneals, I think that you need a controller. There are controllers that regulate a gas valve instead of turning electric power on and off. Eurotherm makes them.

I think that you will waste a lot of energy heating bricks. I still think that if it was a good idea, somebody somewhere would be doing it. I'd be happy if you proved me wrong.