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crystalline firing schedule messing up non-crystalline glazes?

updated mon 4 nov 02

 

Evan Clifford on fri 1 nov 02


Hello everyone,

Would a crystalline glaze firing schedule mess up non-crystalline
glazes? I want to test fire some crystalline glazes but cant fill and
entire kiln. If not would a 1/2 loaded electric kiln have firing
problems because it wasn't full? Thanks.
-Evan

June Perry on fri 1 nov 02


Actually, high calcium matt glazes would benefit greatly from a crystalline
firing. They develop a beautiful matt finish because of the holding time
which permits the growth of crystals from the calcium. I think barium matts
would fit in the same catergory.
Someone else may be able to tell you about other glazes. The best thing would
be to just do a crystlaline firing and include some pieces with your regular
glazes.
From my research on crystalline firing, you don't want the pots too close
together anyway, so having a well spaced out load should not be detrimental.

Regards,
June Perry
http://www.angelfire.com/art2/shambhalapottery/index.html

Ilene Mahler on fri 1 nov 02


no it will just fire faster..Ilene in Conn
----- Original Message -----
From: Evan Clifford
To:
Sent: Friday, November 01, 2002 4:56 PM
Subject: Crystalline firing schedule messing up non-crystalline glazes?


> Hello everyone,
>
> Would a crystalline glaze firing schedule mess up non-crystalline
> glazes? I want to test fire some crystalline glazes but cant fill and
> entire kiln. If not would a 1/2 loaded electric kiln have firing
> problems because it wasn't full? Thanks.
> -Evan
>
>
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william schran on fri 1 nov 02


Evan - I'd recommend a very loose load for your crystalline firing to
allow for a rapid heat rise. We fire a L&L J18 , about 4 cu. ft. and
only get about a dozen pots in the firing.
Bill

iandol on sat 2 nov 02


Dear Evan Clifford,

The results you might get would depend upon the recipes you are =
including with your crystalline recipes and the temperature schedule you =
intend using.

It is possible to predict that any glazes loaded with Magnesium or =
Calcium, or both, would change to matt if they are usually clear, unless =
they are exceptionally high in silica and solvent fluxes.

It is possible to predict that glazes with high volumes of Iron oxides =
would become aventurine.

But in the end, the only thing to do is take the risk and fire a kiln =
load. Call it Research and regard any pleasant outcome as Serendipity

Best regards,

Ivor Lewis,

Redhill, South Australia