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Glaze And Glass?


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#1 Mud crazy

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Posted 01 May 2011 - 07:23 PM

Could anybody please explaine to me the difference between glaze and glass? Thank you Posted Image

#2 Marcia Selsor

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Posted 02 May 2011 - 06:41 AM

This is a very loose explanation.A good glaze will be made of part glass, part clay and part flux.
The ratio between the glass and the clay determine the surface characteristic. The ratio between the flux and the clay determine melting temperature of the batch.
Glass is actually a liquid.."without an ordered structure" <- definition as described in Physics... and even as window panes, it is a very slow flowing liquid.

Marcia

#3 Denice

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Posted 02 May 2011 - 07:46 AM

This is a very loose explanation.A good glaze will be made of part glass, part clay and part flux.
The ratio between the glass and the clay determine the surface characteristic. The ratio between the flux and the clay determine melting temperature of the batch.
Glass is actually a liquid.."without an ordered structure" <- definition as described in Physics... and even as window panes, it is a very slow flowing liquid.

Marcia


Marcia I learned something new a couple of weeks ago, I went to a lecture on glass as part of the Kansas State University open house, the professor giving it said glass is technically a liquid but it never flows. He said it was an old wives tail that old window panes got thicker at the bottom, the process of making glass in the past would leave one side thicker than the others and they would install that side at the bottom for more strength. He said he believed the old wives tale until he started studying glass, he does the glass blowing for the university from extremely fine tube to huge Frankenstein glass assemblages. Denice

#4 Matt Katz

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Posted 02 May 2011 - 08:08 AM


This is a very loose explanation.A good glaze will be made of part glass, part clay and part flux.
The ratio between the glass and the clay determine the surface characteristic. The ratio between the flux and the clay determine melting temperature of the batch.
Glass is actually a liquid.."without an ordered structure" <- definition as described in Physics... and even as window panes, it is a very slow flowing liquid.

Marcia


Marcia I learned something new a couple of weeks ago, I went to a lecture on glass as part of the Kansas State University open house, the professor giving it said glass is technically a liquid but it never flows. He said it was an old wives tail that old window panes got thicker at the bottom, the process of making glass in the past would leave one side thicker than the others and they would install that side at the bottom for more strength. He said he believed the old wives tale until he started studying glass, he does the glass blowing for the university from extremely fine tube to huge Frankenstein glass assemblages. Denice


This is correct.
Glass exists in a state called a "Super Cooled Liquid" meaning that it is still in liquid form, but does not flow at room temperature. For glass to flow in the idea of the old wives tale, they would need either substantial heat or geologic time.

As to the previous question and to clarify Marcia, Glaze is glass, they are one in the same. The major differences is that A) Raw glaze is in the material state having never been melted and is generally composed of Flux (feldspar and Carbonate) Flint (silica) and Clay. The glass that she is referring to is not true unless the formula contains a frit, which is a glaze that has been fully melted and ground into a powder. B ) We add Alumina for stiffness which most traditional glasses excludes because they want to have their molten glass to have a lower viscosity (Flow more) where as if our glazes flowed in the molten state, they would run right off the piece.

#5 Marcia Selsor

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Posted 02 May 2011 - 08:37 AM

Thanks Matt and Denice. As I said..it is a very loose explanation of the difference.
Marcia




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