Neon FAQs

Q1. How do you get the colours?
When electricity is passed through neon or argon gas they glow. 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 colours emitted by the gas. Over the years, tube manufacturers have developed a large range of colours by baking fluorescent powders to the inside walls of the glass tubing. The natural colours of argon and neon can then be 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 colour temperatures from warm to cool. Tubing is also produced in coloured glass. Deep clear reds, blues, and greens for example produce the richly saturated colours referred to as exotic or Euro glass. Coloured glass may also have a fluorescent coating which can change both the quality and colour of the light.

Q2. How do you bend the glass?
The glass is heated and manually shaped by rotating in burner flames. There are 4 main types of burners. Crossfire and fishtail burners are used to 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?
Electrical is passed through the gas via the electrodes at each end of a unit. The current bombards the inert gas atoms with electrons knocking the gas's atoms out of orbit. 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?
Neon tubes are capped off by two glass electrodes which have wire passing from outside to inside. One of these electrodes has an inlet tube which provides a passage from outside to inside. This tube is sealed to a manifold. The manifold has glass stopcocks or valves that allow sections to be selectively opened or closed. A high vacuum pump pulls the air out of the tube while a high voltage-high amperage transformer heats the remaining air to produce temperatures in excess of 500 degrees F. When a very high vacuum is reached and the tube begins to cool, a small amount of neon or argon gas is introduced from a tank. The inlet tube is then heated and pulled away to make a seal.

Q5. Is neon dangerous?
By themselves, neon and argon gas are not, they are inert. As with standard fluorescent tubes, the minute droplets of mercury present in some colours 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 sign is not properly constructed, 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. All Neon Express signs meet current safety legislation and carry the CE mark.

Q6. How long does neon last?
It depends! Apart from the "firey" red neon filled, clear glass tubes, all colours use coated/coloured glass tubes. After some time coatings will breakdown. If the tubes are run using high-powered power supplies ie, giving a very bright appearance, the lifespan of the tube will be reduced. Nonetheless, most coated tubes will last approximately 20,000 hours (again, this depends on power supply the other components used in the sign), thats about 7 years at 50 hours a week use.

Q7. Do you use a pattern or do you bend the glass freehand?
For the sake of consistency and accuracy all neon signs are manufactured over a fire-resistant pattern. Other artistic work can be produced freehand.

Q8. Can neon be used with three dimensional shapes such as a globe?
Yes. Very interesting effects can be achieved because the light tends to fill the object with varied colouration and depending on the power supply, it can respond to touch. This is however an advanced technique.

Q9. Can a neon sign be fixed once it has broken?
Yes. neon signs can be repaired. Most neon signs are made up of several neon sections called units. If one of the units is broken, it may be possible to either repair the unit or make the unit over with new glass and new ends called electrodes. Repairs usually involve heating a new piece of glass and melting it to the original piece of glass. Once the unit has been fixed, the unit is then refilled with gas. Some shops have adopted a policy on not repairing units that have argon-mercury units in them. Neon Express Ltd carry ready-made spare units in stock for quick, economic repairs. If a neon sign has too many breaks in it then it may not be cost effective to repair it.