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Old 11-24-2003, 10:51 AM
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Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 21,956
Pete VanderLaan is on a distinguished road
Gloves, respirators and good ventilation are a must in doing this. If you can't handle those things, don't do it. If you can, making your own glass is incredibly rewarding.

Everthing in the world is dangerous and respect is a good plan. I think what Dave is doing is fantastic.

A glass without a multi valent reducer will not squeeze well. The role is the nitrate creates the sweeping gasses and at high temps the antimony is mono valent. When the temp is dropped, the antimony reverts to a multi valent state and begins to absorb the gasses in the melt back into solution. That is what you are seeing when the bubbles begin to shrink. If you in turn over heat the glass, the valence goes back to a monovalent state and all those gasses are thrown back into the melt.That is called re boil.

Bottom line, squeezing without antimony is slow and expensive. It is necessary in unoxidized formulas using copper and silver. A little fluorspar helps change the viscosity of the glass and shortens the time up. I use the antimony. It's not going to hurt you unless you stick it in your mouth.
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