Everything you ever wanted to know about NEON

Courtesy of Krypton Neon

The Neon Frequently Asked Questions List

Compiled by and Copyright 1994-96 by Kenny Greenberg

Permission is hereby granted to copy and redistribute only if
my copyright notice and mail tags are not changed.
For permission to reprint or to submit additions, contact the author.

Q1. How do you get the colors?

A1. The initial color source is the inert gas which emits a characteristic color when electricity is applied. The two most common gases are neon which emits a fiery red, and a mixture of argon and minute particles of mercury which emits a subdued blue. Clear glass allows you to see the characteristic colors emitted by the gas. Fluorescent powders may be painted or baked to the inside walls of the glass tubing and the source light is then converted into a multitude of shades such as pink, turquoise, and green. By altering the mixture of elements, subtle differences are possible. For example, white is available in a wide array of color temperatures from warm to cool.

Tubing is also produced in colored glass. Deep clear reds, blues, and greens for example produce the richly saturated colors referred to as exotic or Euro glass. Colored glass may also have a fluorescent coating which can change both the quality and color of the light.

Q2. How do you bend the glass?

A2. The glass is rotated and rocked (rocked and rolled) in burner flames which use a gas and air mixture to raise the flame temperature. Generally four burners are used. Crossfire and fishtail burners produce most angled bends and splices. Ribbon burners produce curves or sweeps. Hand torches are usually used for splices or tapering and tipping off electrodes.

Q3. How does a neon tube produce light?

A3. Electrical current bombard the inert gas atoms with electrons knocking neon's atoms out of their orbits. The electrons collide with other free electrons sending them back toward the atoms. As the electrons are absorbed into the atom, energy is given off as light.

Q4. How do you get the gas into the tube?

A4. Neon tubes are capped off by two glass electrodes which have wire passing from outside to inside. One of these electrodes has a tubulation, a small tube which remains as a passage from outside to inside. The tubulation is sealed to the pumping system or manifold. The manifold has glass stopcocks or valves that allow sections to be selectively opened or closed.

An ultra high vacuum pump pulls the air out of the tube while a high voltage-high amperage transformer bombards and heats the remaining air to produce temperatures in excess of 500 degrees F. This allows the tube to achieve a higher degree of purity. When a very high vacuum is reached and the tube begins to cool, a small amount of inert gas is introduced from a flask or tank. The tubulation is then heated and as it is pulled it sucks in to make the tubes own seal.

Q5. Is neon dangerous?

A5. Neon and argon gas by themselves are not. They are inert. As with standard fluorescent tubes, the minute droplets of mercury present in some colors are safe as long as the tube is not broken. Improper handling can be a threat to both the environment and health. Many modern neon shops refuse repair of broken argon-mercury tubes for this reason.

Neon is powered by voltages in the 2,000 to 15,000 volt range. Even though the current is in the milliamp range, if a neon piece is not properly mounted, wired, and insulated this voltage poses both a shock and fire hazard. This is an area where cheapness does not pay off. A well constructed neon piece should be problem free for many years.

Q6. How long does neon last?

A6. Neon can last decades In practical terms the expected life span is between 8 to 15 years. Neon can be repaired and recharged.

Q7. Do you use a pattern or do you bend the glass freehand?

A7. For most applications (signs, designs, etc) neon is bent over a fire resistant pattern. Artistically expressive work is often freehand. Three dimensional work from engineer drawings or a dimensional template is very challenging but can be done.

Q8. Can neon be used with three dimensional shapes such as a globe?

A8. Yes. Very interesting effects can be acheived because the light tends to fill the object with varied coloration and depending on the power supply, it can respond to touch. This is however an advanced technique.

Q9. How do they make neon appear to move?

A9. The huge animated neon signs or "spectaculars" of the 1940s have multiple layers of neon each powered in a timed sequence to produce the desired effect. Many other forms of movement have been found in the neon tube itself. "Wiggle tubes", "Crackle tubes", "Jelly beans", and "Whirlygigs" are a few.

Q10. Do you burn or cut yourself?

A10. Once every six months. :-)

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Last Update: July 28, 1996
Copyright © 1994-96 Kenny Greenberg.
All rights reserved.