Producing
a Neon Tube
Bending the Tube
Most
neon tubes are made from lead or soda-lime glass tubing that is commercially
manufactured and supplied in 4'-5' lengths. Commercial tubes come
either in clear or colored glass and may be coated with special phosphor
powders which contribute to the final color of the tube when it is
lit. In some cases, the tubing is made from hand blown glass with
the help of glassblowers at local hot glass studios.
The
artist cuts the tubes to desired lengths then "welds" them
together in whatever color combinations chosen using cross-fires to heat the glass. "Welding" is
accomplished by heating the ends of the tubes in open natural gas
fires until they are hot enough to be melted together. Prior to this
welding, the artist may remove some of the powders in striped or other
patterns to enhance the final appearance of the tube. After sections
of tubing are welded together, electrodes are welded to both ends,
sealing the tube and providing the means by which electricity ultimately
can be delivered to the tube to light it. (QuickTime movie of "welding"- a large file
for fast internet connections only)
This
tube, now the chosen length and color(s) with electrodes attached,
is then bent by Ehlenberger in open gas fires to the desired
3D shape or pattern. Various types of fires and torches are used in
bending the neon tube, from hand torches that allow for intricate
bends to "ribbon burners" that allow the artist to
heat long sections of tubing at one time for long, sweeping
bends. The welding and bending of the neon tube is where the skill
of the artist comes to play, as the hot glass is rather unforgiving
of error. Mistakes often require starting all over again! (QuickTime movie of bending in the ribbon fire- a
large file for fast internet connections only)
Processing the Tube
Once
the neon tube has been bent and shaped to its desired form, it needs
to be processed to enable it to be lit. Processing a neon tube is
is technically demanding as the process must by done absolutely correctly
or the tube will fail to function properly. The new neon tube is first
attached to a manifold, a system of tubes, stopcocks and gas flasks
in conjunction with a powerful vacuum pump. When the neon tube is
perfectly sealed airtight to the manifold, a partial vacuum is introduced
into the tube and a very high voltage current is applied to the tube,
a process called "bombarding". This electrical current serves
to heat the remaining air in the tube to just below the temperature
at which the glass will begin to sag. Heating the tube in this way
vaporizes whatever impurities, especially water, that have remained
in the new neon tube. When the tube temperature reaches its maximum, approximately
200 degress centigrade, a full vacuum is applied to the tube to evacuate
all remaining air and impurities from within the tube.
Only
when the tube has been thoroughly evacuated can the neon or other
inert gas be introduced into the tube via the manipulation of stopcocks
and gas flasks. Once the gas is put into the tube at the appropriate
pressure (still less than atmospheric pressure, a partial vacuum),
the tube can be removed carefully from the manifold. The tube is now
finished and ready to be used though it should be aged for a little
while to allow the tube to mature.
This
processing of the tube not only requires careful attention to detail
to provide a quality tube but also to ensure the safety of the individual
processing the tube. Voltages in excess of 10,000 volts are applied
to the neon tube during processing and a careless error in this stage
can be fatal to the operator. It should be pointed out that such dangerous
voltages are used only in the processing of a neon tube and not in
the neon sculpture!
From
its inception at design to its final manifestation as a luminous sculpture,
each neon tube is hand made and processed individually with careful
attention to detail. Our studio takes pride in the quality of work
generated with the expectation that it will provide years of trouble
free service.
|
