Candice Roeder on thu 3 feb 05
Hi all,
I've been doing pit firing for years, and am now beginning saggar firing. In reading about saggar firing methods, I see that people are using various chemicals within the saggars for fuming.
I am familiar with using Copper Carb and Copper Sulfate, and know they fume well, particularly when combined with salt (I do not know why the salt helps the fuming).
I see many are using Iron Oxide, Copper Carbonate & Copper Oxide and Yellow Ochre in their firings.
I thought these chemicals didn't fume (volatilize?) at low temps (cone 012-010).
Wouldn't the Sulfate forms of cobalt and iron be more apt to fume?
Would combining salt with the iron oxide, cobalt carbonate cause them to fume at lower temperatures?
I can find online data listing the melting points of these colorants, but how do I find the fuming temperature (or are they the same)?
I plan on soaking combustible materials in the above, but prefer not to waste my time, chemicals & money if they're just not going to fume.
Thanks for any insight.
Candice Roeder
Vicki Hardin on sat 5 feb 05
I never had much luck with oxides in pit fires and prefer sulfates. Root killer can be used for copper sulfate. Also, I have used nails dissolved into nitric acid instead of ferric chloride and prefer it as it gives a more intense color. I am not sure about the exact fuming temp, but suspect it is at or just below 1000. I use aluminum saggars and watch for when the aluminum starts to dissentigrate. That is my marker. All the usual saftey precautions apply.
Cheers.
Vicki Hardin
http://vickihardin.com
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