Bill Amsterlaw on mon 24 mar 97
Hi Clayart:
We have seen a number of recipe's for woo yellow and warnings from Richard
Burkett and Ron Roy that this glaze probably releases unsafe levels of barium.
I am wondering: Why is this glaze is yellow? Does it come from the iron, the
combination of iron and zircopax? What conditions promote the development of
yellow in a glaze that you might expect to be red or brown?
- Bill Amsterlaw (wamster@msn.com)
Plattsburgh, NY
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Woo Yellow
(cone 9-10 reduction)
>>
Color: Yellow Opaque
Testing: Tested
Surface texture: Stoney Matt
Firing: Reduction
Glaze type: Ba Ca Mg
Recipe: Percent Batch
Kona F-4 Spar 39.29 1964
Barium Carbonate 29.76 1488
Dolomite 14.29 714
EPK 8.33 417
Flint 8.33 417
Totals: 100.00 % 5000 Gm
Also add:
Zircopax 17.86 893
Red Iron Oxide 3.57 178
Possible Health Hazards:
Barium Carbonate: HIGHLY Toxic-avoid ingestion. Do not use in glazes intended
for use with food.
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