Thread: Color bubbles
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Old 11-05-2017, 01:37 PM
Marc Carmen Marc Carmen is offline
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Originally Posted by Pete VanderLaan View Post
Mark talked about cad/sel reds in fluorine that started off compatible in his work and by the time he was done, they were no longer compatible. The effects of heating and cooling repeatedly in a glass does often change them. While John is really cautious about using Hagy seals to determine mismatch, those efforts can sometimes be defeated. The description of the black makes me think of those circumstances.
I've worried about this as well. Theres definitely some crystal growth going on. Some of the FeS test melts I've done needed to be struck from a dark trans brown to that characteristic gritty graphite black, but only if the melt wasn't reduced enough.

I've never had compatibility problems though. Then again, the density of the color never requires more than a thin overlay or a fine cane.
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