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Fused Glass...
...simply refers to the process
of using a programmable kiln to partially melt pieces of specially-formulated
art glass into one new, unified piece of glass. Color patterns & designs
developed by the fusing artist are retained by carefully controlling the kiln
firing schedule.
Many glass fusers use dichroic,
iridescent, transparent, and opaque glasses that have a COE (coefficient of
expansion) of 90. Not to bore you with too many technical details, but
this simply means that the various pieces of glass fused together have to be
compatible in their rate of heat expansion and cooling contraction.
Otherwise, the resulting fused glass piece can later exhibit stress fractures --
sometimes weeks or months later!
My glass fusing "set-ups" are
typically hand-cut and pieced together much like a vertical mosaic layering
process. I also use a band saw for more intricate cuts, or for cuts on
multi-layer thicknesses of fused glass.
Each glass item on this web site
is kiln-fired over a period of about 4 hours, at minimum. Most pieces are
comprised of 2-5 layers of glass, which is how the patterns and designs are
built up. During a full fuse -- where all individual elements of glass
slump into one smooth cabochon -- temperatures of up to ~1500ºF are typical.
For a tack fuse, some of the layering and texture effects are preserved by
fusing up to about ~1400ºF.
After fusing, the glass is held at a temperature that allows all the different layers to unite, in
terms of their expansion/contraction, by "soaking" at about 1000ºF.
This is called "annealing". It is
important to sufficiently anneal the glass, otherwise stress fractures and
inclusions can later appear in the glass -- even in compatible glass.
At this point, I usually need to
do a little bit of clean-up on the fused pieces. I use a glass grinder to
whittle down any rough edges, or to true-up a square, for example. Because
this process will leave grinder marks on the glass, pieces are
"fire-polished" by firing a second time at a lower temperature to remove the
marks. Once again, the piece must be annealed after the second firing.
Dichroic Glass:
Di- Chros...
as in "two
colors"
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Dichroic
glass was developed over 100 years ago. In recent years it was
perfected by NASA for use as a filter on the windows of the space
shuttles. It has the unusual property of reflecting one color
(when placed against a dark background), while transmitting another
(when held up to the light).
Dichroic
has a shimmering effect
similar to the iridescence observed in an opal.
Quite simply, different colors can be viewed in dichroic glass by examining it
at different angles. The colors are brilliant, saturated wavelengths of
light, making them exciting additions to jewelry and decorative houseware items. |
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19" sheet of rainbow "marquis" patterned
dichroic glass |
Production Process
Dichroic glass is manufactured
in an ultra-clean environment, making it one of the most expensive glasses made
today. The process involves depositing many very thin layers of rare metal
oxides (magnesium, silicon, titanium) on the surface of a piece of glass.
A clean sheet of glass -- typically 19" in diameter -- is affixed to a rotating
arm within a special vacuum chamber. A container of the designated metal
oxides is placed in the chamber. An electron beam vaporizes the oxides,
and the resulting particles evenly coat the rotating glass sheet.
Dichroic glass is available in a
wide range of color combinations, textures, and patterns. It is difficult
to accurately show the brilliance and iridescence of the colors on a web site,
given differences in computer monitors and control panel settings.
Thanks for taking the time to visit my site and
learn more about the fusing process.
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