Flux is a term that refers to a substance that is used to lower
the melting temperature of a metal, glass, or other material.
The term is used in many segments of the glass field, from stained
glass (where it refers to zinc chloride, a product that helps solder
flow) to glassblowing (where it refers to substances like soda ash
or potash, which are added to the glass batch to help it melt at a
In the world of glass fusing, the term flux most often refers to
oversprays which are used to help the fused glass resist
devitrification. Flux is often used glass enamels, and can
lower the melting temperature of many glazes and sprays.
Fluxes can also be used to dilute colors and make them more
In the fusing world, crushed glass containing borax and
(sometimes) lead are common flux ingredients. Fluxes are
available that work in many different temperature ranges, from just
below 1000F/540C to well above 2000F/1093C.
Copyright 2006 Brad Walker.
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