Thread: Devardi cracks
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Old 2009-11-20, 7:27am
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pam pam is offline
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Great answers, Luna!!! You were thinking only of the physical as opposed to the chemical.

1. What makes glass rods shocky? Air in the rods.Take it a step farther, why is the air get in the rods

2. What causes glass to need to be worked at lower temperatures or in the back of the flame? same thing? Having to work glass cooler can be a remedy for shocky rods, but think of chemicals that if added or taken away could cause this.

3. What makes a glass stiffer even though it has the same coe as another glass? I believe Tink & John said "viscosity", & that's from the chemical makeup of the glass. Good, so dig deeper.

4. What causes a glass not to flow so that it cannot be shaped in the flame? Lack of heat, or lack of viscosity And what causes this to happen?

5. What is "burning" glass really and why does it happen? Too much propane in your flame.Very good, almost there. Now why does an excess of propane do this on some glass and not others?

6. How can the chemical composition of glass be changed by adding heat? I'd have to ask a chemist, but I'm sure they'd have an answer. Or you could do the research yourself and find out the reason.
7. What causes glass to foam? Think along the lines of the batching process.
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