How Fused Glass Art Is Produced
Fused glass can be produced in a very wide range of shapes and sizes. The colors are limited only by the selection of art glass
you can find. There are many manufactures of glass around. The Bullseye Glass Company manufactures most of the glass used in my
studio. The most important thing about the glass is that it must be compatible glass. All of the glass used must have the same
COE (coefficient of expansion). Different glasses will expand and contract at different rates if this rate is too great stress
will build up in the glass. If there is too much stress created in the glass the piece can develop fractures and can even shatter.
Some glass may be not compatible even with the same COE. This is why glass manufactures must test their glass to make sure it is
useable for fusing. This is also one reason why art glass is very expensive. A single sheet of glass 36" X 20" can easily cost
over $100 dollars. The following companies all produce tested compatible glass Bullseye, Spectrum, Uroboros, Wasser, Gaffer,
Effetre and other smaller companies
Production of Large Plate
1. The first step in the production of a large plate is the selection of the glass that will be used for producing my artwork. I
try to use various colors and patterns that will complement each other. Plates are most often made by stacking three separate layers
of glass and then fusing them. I usually start with a colored bottom layer of glass.
My next step in producing a large plate is to
use a circle cutter to scratch a line into the glass sheet.
You can then use controlled pressure to run a line (fracture) around the circle to pre-break the glass. You then can use a hand glass
cutter to make small cuts around the glass circle to remove it from the large sheet of glass. A top sheet of clear glass is then cut out and placed on top of
the bottom sheet. The round glass pieces may have small areas, which need to be removed to smooth the edges. The easiest way to
remove this glass is to grind it with a diamond coated wheel. This is now your "canvas" for your design. I then start building
the design for the plate. I often start the design by using interesting shapes or patterns and build from there. These shapes
are cutout using a small hand cutter. Similar to the familiar glasscutter that may be used to cut window glass. This is a very
individual process. Everyone will have his or her own ideas for doing this. Stained glass pattern books are a good source of
designs. You can also make your own patterns from your personal photos.
2. Before you move your piece into the kiln you can glue the parts together using common household
white glue and a toothpick. Just put a few small spots on each separate piece and let dry. This
does not have to be done but can save you work if you are unsteady in loading into the kiln. If your
unfired artwork has many small pieces or you need to transport it to someone else's kiln this can
be especially important. Once the pieces are all cut out and arranged it is loaded into the kiln.
It is then heated to a temperature of around 1450 - 1500 degrees Fahrenheit. This process takes
many hours to complete. There are several stages the glass must go thru. These stages are
heating phase, soaking phase, rapid cooling phase, annealing phase and cooling to room temperature
phase. The various times and temperatures needed are programmed into the kiln's electronic
controller. This makes up what is called the firing schedule. These processes cannot be rushed or
the glass can fracture now or latter due to stress buildup.
Slumping fused piece
3. Slumping the flat glass over, into or through a mold makes the shape of the piece. The molds
used can be made of clay, stainless steel or other materials.
The flat glass is placed on the mold and then placed into the kiln. The piece is then fired to a
temperature around 1200 to 1300 degrees Fahrenheit. This is another firing schedule that takes
many hours to accomplish. These firing schedules will vary depending on the type of glass used
and the size and thickness of the glass piece made. Telescope mirrors can take a year or more to
finish a firing schedule.
This is not a complete description of the process just the main processes. There are many good books
available about glass fusing. There is also a lot of information available from the many
manufactures of art glass.