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General Category => Tools => Topic started by: Administrator on January 25, 2019, 07:34:23 PM

Title: Compatibility Testing: Ring test
Post by: Administrator on January 25, 2019, 07:34:23 PM
I really like the ring test. You apply a stress to the glass and see if it can take it. I make a cylinder large enough to allow a few rings to be cut out of it. It can be a thick ring test or a thin ring based (I think) on the types of final glass you will be making. I make the thicker type with walls around 1/4"-1/2" thick. I've got a large 14" tile saw and just make rings starting from the center of the cylinder. Making a single ring from the top is kind of cheating and doesn't mean an "internal" ring will survive.

When a ring makes it you can slice it to see if it has much stress built up. If it closes a bit, the outer layer has a higher LEC than the inner layer. You need to make both an encased and outside version of your test glasses to be sure they are fully compatible. I have an opal phos which works when it is on the outside, but cracked immediately on the saw when encased.  >:(