marie elaine on thu 18 jun 98
I have been searching the clayart archives, yahoo, CM magazines, for any
reference or leads on ^4-6 oxidation metallic glaze formulas. The only one
I've found is ..."Reynolds Gold Metallic Glaze", (source: CM magazine,
Feb.92, page 76, see below).
I'm ready to experiment with another glaze. I want a metallic color, red,
blue, would love to have something in silver. I have had a modest exposure
to formulating glazes, but am by no means feel competent to start from
scratch. Can you help?
These are some questions I'd appreciate your commenting on:
1.I'm wondering if I can use the base for the Reynolds glaze ( toxic, non
food safe) and substitute its colorants with other compounds that would
give me the colors I'm after. And, what oxide combinations do you suggest
trying?
Black Copper Oxide 4.0
EPK 4.0
Flint 4.0
Cobalt Oxide 2.5
Manganese Dioxide 36.5
Cedar Heights Redart 49.0
2. Is this formula a toxic, non food safe glaze too? (source: Pottery
Making Magazine, vol.1, no.1, page 37)
Purple Icing ^6 Oxidation
Gerstley Borate 6.2 %
Lithium Carbonate 2.0
Magnesium Carbonate 6.1
Strontium Carbonate 12.1
Whiting 12.1
Neph. Sy. 21.0
Flint 40.0
Total 100.0
Add
Tin Oxide 3.0
Cobalt Carbonate 1.0
Bentonite 2.0
3. In the above formula what are the correct gram amounts for a 5 gallon
batch of glaze. Do I simply mulitply the percent amount by the number of
gallons, ie. 6.2 x 5 = 31?
4. Do you have another glaze formula that you think I may be interested in
trying that will give me the metallic look I'm after?
Looking forward to your response.
Where it is still in the smothering upper 90's here in florida.
marie elaine
Ron Roy on mon 22 jun 98
Hi Marie,
It's more like a cone 04 glaze - not durable at cone 6 - Any toxins will
leach out if fired to cone 6 - probably change colour in use as well.
>2. Is this formula a toxic, non food safe glaze too? (source: Pottery
>Making Magazine, vol.1, no.1, page 37)
>
>Purple Icing ^6 Oxidation
>
>Gerstley Borate 6.2 %
>Lithium Carbonate 2.0
>Magnesium Carbonate 6.1
>Strontium Carbonate 12.1
>Whiting 12.1
>Neph. Sy. 21.0
>Flint 40.0
> Total 100.0
>Add
>Tin Oxide 3.0
>Cobalt Carbonate 1.0
>Bentonite 2.0
Any glaze with metals right there on the surface will contaminate food -
simply because there is nothing to stop them - like a covering of durable
glaze.
Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Web page: http://digitalfire.com/education/people/ronroy.htm
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