Thread: Color bubbles
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Old 05-17-2015, 06:38 PM
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Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 21,503
Pete VanderLaan is on a distinguished road
This is a repetition of something I've said before but it bears repeating:

When we used to make color, particularly fluorine rods, we would gather the glass three times and then roll the rod. Speed was important to profit. Fluorine opals are transparent drawn from the pot so we could see if there were issues. We would draw a perfect rod, roll and box it. In the morning, I took one of every five rods and ran it through a diamond saw vertically to see where problems might arise. Those rods had bubbles the same size as Swiss cheese in them.

So, I changed technique and once the rod was formed, we reheated three times which slowed our process down enormously. The diamond saw work revealed a flawless rod.

Kugler for a while made rod casting them and they all had a string of bubbles down the core and to this day I believe they were having the same problem I had. Glass demands that you be patient. It doesn't tolerate shortcuts.

Dan Fenton : "Glass remembers everything you ever do to it."

Sleep on Buddy.
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