Randy and Cheryl Weisz on tue 3 jul 01
Hi Ron,
Thanks for your information and re-formulations. I had considered
reformulating the glaze using custer feldspar instead of the nepheline. Like
your suggestions, I had already used Insight to come up with this possible
alternative:
Dolomite 19.52
Ball Clay 20.04
Frit 3124 20.77
Silica 12.05
custer Feldspar 27.62
The resultant unity formula is nearly identical to the original recipe with
the major exception being the soda to potash ratio. The combined amount of
the two fluxes are the same... but, the original recipe had a K2O to Na2O
ratio of 1:4, compared to the custer feldspar alternative which has a ratio
of nearly 1:1.
I had assumed that this would result in a significant change in the
appearance of the glazes that we make from this base. You and several
others suggested making custer feldspar type reformulations. Is the ratio
of these two fluxes generally not as important as their combined amounts in
the unity formula?
Thanks!
Randy Weisz
> From: Ron Roy
> Reply-To: Ceramic Arts Discussion List
> Date: Mon, 2 Jul 2001 01:33:58 -0400
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Re: Help w/ suspending difficult glaze
>
> Hi Randy,
>
> It's the Neph Sy - and/or maybe the glaze is just too thin in the bucket -
> and/or maybe it's the water. Any way here is the same glaze without the
> Neph Sy - let me know if it needs adjusting - test it first!
>
> G200 - 22.5 (Custer will work)
> Dolomite - 20.0
> F3124 - 19.5
> OM4 - 21.5 (other ball clay may work as well)
> Silica - 16.5
> Total - 100.0
>
> Here is another using a different frit - cheaper way to go with evem more
> clay to keep it all up.
>
> G200 - 23.0 (Custer will work)
> Dolomite - 20.0
> F3134 - 12.0
> OM4 - 28.0 (other ball clay may work as well)
> Silica - 17.0
> Total - 100.0
>
> Let em know if some adjustments are needed - send all the recipes and what
> the differences you want changed - fire all tests with a large cone beside
> them - this is absolutly necessary.
>
> RR
>
>> We have been using a variation of a Cone 6 base glaze found originally in
>> Ceramics Monthly 12/1981. We like many of the colors, but the glaze settles
>> out very fast, and if not mixed up every few minutes, forms a very hard
>> layer on the bottom of the bucket. Epson salts have little to no effect.
>> Can any one tell me:
>> 1) which materials in the glaze are causing this problem,
>> 2) would adding bentonite to the glaze help?
>> 3) any other ideas to solve the problem?
>>
>> The base glaze recipe:
>>
>> Nepheline syenite 20%
>> Dolomite 20%
>> Frit 3124 20%
>> Kentucky Ball Clay 20%
>> Silica 20%
>
> Ron Roy
> RR# 4
> 15084 Little Lake Rd..
> Brighton,
> Ontario, Canada
> KOK 1H0
> Residence 613-475-9544
> Studio 613-475-3715
> Fax 613-475-3513
>
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