Thread: ring tests
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Old 12-10-2016, 10:24 AM
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Pete VanderLaan Pete VanderLaan is offline
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It reads the glass on the inside has a gap and is slightly lower expansion than the outside glass. The proportions are very good. The very fact that the ring survived the saw is a solid indicator that the two glasses are reasonably matched. Ideally, you want the scored vertical part to simply sit at rest, neither opening or closing on itself. I would either add a small amount of soda ash to the black, or a small amount of silica to the outer glass. Small for me is about 25 grams in 30 lbs or so. Then melt and measure. One of the two glasses would of necessity have to be a batch glass to add the sodium or silica although it's possible to add soda or silica to SP87. Otherwise, it simply is what it is. At .026 I would try to close the gap.

Good Job.
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