Thread: ring tests
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Old 10-22-2019, 06:09 AM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
Join Date: Apr 2002
Location: Chocorua New Hampshire
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Surface tension is really important so when you put the mismatch glass out there, you see quick results.

On the pull test, the glass on the inside of the curve has a higher expansion
On the ring test the inner glass gapping open indicates the inside glass has a lower expansion.

The annealing part is something I threw in as curious and I can't say why. It is the case that substantially different formulas make the pull test less than reliable. Go read about it in Glassnotes IV
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