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fw: soda spar vs. soda ash

updated thu 21 dec 00


Jewel Rubin on wed 20 dec 00

Hi Paul and Tom.

I thought you guys would be interested -- I did my glaze firing yesterday.
I fired one test pot with the original mistake glaze, one pot with Paul's
first suggested change (adding EPK & Silica), and then one pot with Paul's
suggestions to correct the recipe.

The most interesting results were with the original mistake -- the inside of
the pot did not run or craze, but it broke sort of amber with textured
crystal glitters. Rather exciting. I poured some satin white over the top
of the outside and it ran like mad.

With Silica and EPK added the glaze became more matte, but less textural and
with some crystalline shine (I hadn't removed the crystals completely when I
used this batch). The final recipe was matte, but not especially exciting.
Dipped on a white clay cup, too thick I think, it also ran.

I'm giving serious thought to adding back some of the crystals I saved when
I use the black again. This was fun!!! Thanks for your help. Have a great
Jewel Rubin
Roswell, GA

----- Original Message -----
From: "Paul Lewing"
Sent: Thursday, December 14, 2000 11:47 AM
Subject: Re: Fw: Soda Spar vs. Soda Ash

> Hi, Jewel.
> Assuming you replaced exactly half of the soda feldspar with soda ash,
> by my calculations, if you add 6 EPK and 5 silica to your mix, you
> should be pretty close to what you would have had with all soda spar.
> However, this does not address the solubility issue. And the trick of
> Tom's to try to get the soda ash to crystalize out is a new one on me.
> Did you try it? I'd be interested to know if it worked. Wouldn't
> surprise me, though. Tom Buck's a genius.
> Let me know how this all turns out, please.
> Paul