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Old 03-30-2005, 07:11 PM
Henry Grimmett
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jade green

Robert,

The jade green was never tested for COE by Paul. It was tested by 2 other people who wanted to know about the glass. Both found the glass to be in the 35 range.

The glass does not contain fluorine and the cracking in the early days (prior to mid 98) was poor formulation. After that date the cracking was closely related to reduction during working or phase seperation issues during extended "garaging" at high temperatures.

And yes, the viscoity curve and rate of heat loss during cooling of the borosilicate glass is very important to fit, maybe more so since the metal oxides tend to much denser in the boro glasses than in the soda-lime.
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