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Old 10-03-2019, 10:17 AM
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Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
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Quote:
Originally Posted by Shawn Everette View Post
but rather specific reds that are incompatible across the board.
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Most color rod has a 24% lead content and it allows for a remarkable amount of tolerance regardin mismatch except when you penetrate the surface tension of the piece as in sawing and grinding.

Reds and yellows are a different animal in that the presence of lead in the glass causes cadmium based colors to turn a shit brown. Selenium by itself is still clean with lead but not cadmium. So, those rods have zero lead in them and subsequently have no tolerance for mismatch. The Germans pretty much made those expansions down around an 85. The only cadmium rod that attempted working near the 96 quasi standard in the US is Gaffer. Enamel whites have about the same amount of lead in them plus about 6% arsenic which the EU is essentially banning in Europe. That is why the search for the titanium phosphate glass Peiser is currently pursuing is important. We did some work on that in my first color class here but Mark carried it on alone within about six months. I think he got up to 200 + melt tests. It is still really dicey to produce in any volume though.
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