Neon glass signs are made of neon tubes bent into shapes and filled with gas. When the electric hits the electrodes in the tubes, electrons flow through the gas, making its atoms glow. The type of gas in the tubes, determine the color of the light.
In a clear glass tube, argon gas gives off a steel blue light while neon gas produces red light. To create vivid designs, we can parlay the two base colors into over 80 different colors by using glass tubes that are coated in fluorescent powders. For instance, blue glowing argon gas in a yellow tube, emits a green light.
To shape the tubes, we use a glass blowing technique. Following a pattern drawn on a fire resistant sheet, we mark the tubes where we need to bend it. Then we heat each spot on a device called a ribbon burner which has a propane flame at 650'C. Within about 30 seconds, the glass becomes soft enough to be pliable. We gently bend the tube, then blow air into the uncorked end to restore the original diameter. With each bend, we check the shape against the pattern.
After shaping we cut off the excess and remove any extra powder residue from inside of the tube ends. The next step is to attach the glass tube neon electrodes by fusing the two together with a propane hand torch and a flexible latex blowing tube. We seal the glass around one electrode and leave the other open. Then using a crossfire burner, we create a tubulation which is merely a bubble that can act as a passage way into the open electrode. We then fuse the tubulation to the open electrode. We now add a drop of mercury into the tubulation to brighten the color of the argon gas. Without the mercury, the argon gas would not be as bright. Neon gas (a red neon sign) does not need mercury.
Using whats known as an end torch, we fuse the open end of the tubulation to a long glass tube that leads to a pumping system. We connect the electrodes to the system and power it up. The pump vacuums out the air in the neon sign and injects the gas. The electrical current makes the atoms in the gas glow. To trap the gas inside the tube, we use the crossfire burner to remove the tubulation and seal off the open electrode, making sure the drop of mercury has fallen into the electrode first.
The next step is to dip the back of the neon sign into black paint which will help the lettering and design stand out. We use a brush to spread the coat evenly and remove the excess. We then light up the sign at high voltage for about 30 minutes. This will dry the paint but most importantly it will transform the liquid mercury into vapor which will spread through out the inside of the neon sign.
Using transparent clips, we mount the sign onto a black or clear plexiglass backing. Finally, we connect the protruding electrode wires to a neon transformer. A neon transformer converts the standard 110 volt current, from our normal wall outlets, into high voltage current (3k to 15k volts) needed to power a neon sign.