Author Topic: What causes this type of flaw in glass?  (Read 600 times)

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Offline TxSilver

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What causes this type of flaw in glass?
« on: October 30, 2008, 07:34:44 PM »
I have an Archimede Seguso vase that has several flaws in it. The flaws are like filled craters in the casing glass. The glass feels smooth over the blemish, but you can feel the borders of the flaws if you use your fingernails. I wondered if bubbles or liquid in the glass could cause this during annealing. Or does this vase have small, multiple impacts?
Anita
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Offline Frank

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Re: What causes this type of flaw in glass?
« Reply #1 on: November 01, 2008, 01:28:10 PM »
If they are bubbles near the surface, water vapour will get into them over time and cause them to whiten (Unless stored in low humidity). If impacts that wont happen, but you should see some mirror like surfaces using a spotlight at different angles. Hard to say from the pictures. Bubbles near the surface can occasionally be felt but impacts should have a very sharp line at the edges that you might feel with a fingernail.
Frank A.
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Offline Bill G

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Re: What causes this type of flaw in glass?
« Reply #2 on: November 01, 2008, 04:54:40 PM »
Hello:

Another answer is when the work is overlayed with clear glass, their is a small indentation in the form being
encased and air will form into such a bubble near the surface.

When experimenting with the ariel technique, I could create within the form, encased bubble designs in the indented form being encased. Not a true ariel technique, but a way to encase air in the form.

Bill Geary


Offline Frank

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Re: What causes this type of flaw in glass?
« Reply #3 on: November 01, 2008, 05:10:47 PM »
Thats true Bill, I notice too that there are some 'bits' in the glass, if any of those vaporised while casing the result would also be a bubble.
Frank A.
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Offline TxSilver

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Re: What causes this type of flaw in glass?
« Reply #4 on: November 01, 2008, 05:35:09 PM »
Thanks, Bill & Frank. I hoped that they were bubbles, but they were so wide I was unsure.

Anita
Anita
San Marcos Art Glass
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