Trying to find a couple new glazes and am interested in a turquoise yellow salt glaze that I found in an old clayart topic from 2000 by Dr Tom Roess. I understand all the ingredients but it is the quantities of colorants that do not make sense to me. I know there are participants here that will be able to explain it to me. (Thanks for your help).
Here is the recipe:
TURQUOISE YELLOW SALT CONE 10 REDUCTION
Neph Sy 63.9
Ultrox 16 (use superpax)
OM 4 clay 4.3
1/8 =25 Cobalt Carb
2 =25 Copper Carb
To 10,000 grams add 1/2 C. Muriatic Acid
My question pertains to the amounts of cobalt carb and also the copper carb. The amounts seem incredibly high -might the base recipe have been written for 105.3 plus 4 bentonite grams, and the colorant additions were listed for a 10,000 gram recipe? Is my guess anywhere close to explaining this. Would appreciate help with the correct colorant amounts - cobalt is too expensive to waste!
I will be firing this in a gas kiln fired with LP, to cone 10 R - not a salt kiln
Thanks for sharing your knowledge!