Layna Portugal on thu 10 oct 96
Our studio uses a Cone 10 glaze called Hamada Turquoise. It occasionally
looks sugary or crystallized in areas. This glaze fluxes A L O T. What
causes this? Is it dinnerware safe?
--
"Save da drama for yo moma...word" Peter D
lunar@enteract.com
http://www.enteract.com/~lunar
Ron Roy on sun 13 oct 96
>----------------------------Original message----------------------------
>Our studio uses a Cone 10 glaze called Hamada Turquoise. It occasionally
>looks sugary or crystallized in areas. This glaze fluxes A L O T. What
>causes this? Is it dinnerware safe?
>--
>"Save da drama for yo moma...word" Peter D
>lunar@enteract.com
>http://www.enteract.com/~lunar
The longer a kiln takes to cool the more crystalization - Send me the glaze
recipe and I will give you my opinion if it is safe.
Ron Roy
Toronto, Canada
Evenings, call 416 439 2621
Fax, 416 438 7849
June Perry on sun 13 oct 96
Some glazes get that sugary look when they overfire. Is this happening on a
new batch? If so the calculations, weighing, etc. may be off. Are you using
new cones that may be melting later? Another possibility is that a new
supply of raw materials has a different composition and is giving your
greater fluxing in the formula.
Regards,
June
Layna Portugal on tue 15 oct 96
At 12:56 PM 10/13/96 EDT, you wrote:
>----------------------------Original message----------------------------
>>----------------------------Original message----------------------------
>>Our studio uses a Cone 10 glaze called Hamada Turquoise. It occasionally
>>looks sugary or crystallized in areas. This glaze fluxes A L O T. What
>>causes this? Is it dinnerware safe?
>>--
>>"Save da drama for yo moma...word" Peter D
>>lunar@enteract.com
>>http://www.enteract.com/~lunar
>
>The longer a kiln takes to cool the more crystalization - Send me the glaze
>recipe and I will give you my opinion if it is safe.
>
Thanks for your interest. We have the reipe in grams...
Kona F-4 2865
Whiting 480
Zinc 440
Strontium Carb 1160
EPK 245
Copper Carb 200
We add l00 g of bentonite
--
"aint no thing but a chicken wing on a string from Burger King...know what
Im sayin?" :)----------?
http://www.enteract.com/~lunar
Ron Roy on wed 16 oct 96
>----------------------------Original message----------------------------
>At 12:56 PM 10/13/96 EDT, you wrote:
>>----------------------------Original message----------------------------
>>>----------------------------Original message----------------------------
>>>Our studio uses a Cone 10 glaze called Hamada Turquoise. It occasionally
>>>looks sugary or crystallized in areas. This glaze fluxes A L O T. What
>>>causes this? Is it dinnerware safe?
>>The longer a kiln takes to cool the more crystalization - Send me the glaze
>>recipe and I will give you my opinion if it is safe.
>>
>Thanks for your interest. We have the reipe in grams...
>
>Kona F-4 2865
>Whiting 480
>Zinc 440
>Strontium Carb 1160
>EPK 245
>Copper Carb 200
>
>
>We add l00 g of bentonite
I have calculated this glaze and compared it to 2 sets of limit formulas -
It has enough silica to make a cone 04 glaze durable. At cone 10 you need
to add at least 35 parts of silica per 100 to make it a stable glaze - even
so there is the copper which is reported to increase solubility. On the
other hand there is little in the glaze to leach out and become a problem -
well maybe the copper and zinc if you believe some of the warnings.
The recrystalization can be handled by adding silica - do a line blend
adding 5, 10, and 15 parts of silica per 100. If it runs then you will have
to add more clay but you can expect colour changes.
We will all be interested in the results - why not post them?
Ron Roy
Toronto, Canada
Evenings, call 416 439 2621
Fax, 416 438 7849
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