I was recently contacted by a woman looking to get her beloved neon sign fixed. It had belonged to her late father, and her teenage son who was very close to him, wanted the sign to hang in his bedroom. Besides being broken, the sign was in pretty rough shape. It was covered in dust, had broken tube supports, and some duct tape residue melted onto the plexiglass panel. Here it is with the broken tubes removed, but before I did anything else to it.
The working neon tubes, insulating caps, and wires needed a good cleaning too.
Looking over the sign, I didn’t agree with some of the design choices that the original sign maker made. The two main issues I had were: the decision to use a thin piece of plexiglass acrylic to mount the neon tubes to, and how close the neon was to the edges of it. It made the whole thing very flexible, bendy, and hard to handle, making it more likely to break again in the future. I could also tell that the sign had already been broken and repaired before, so I suggested to the owner that I make a few improvements to make the sign less fragile and in good shape for years to come. She agreed, so I set out to give the whole thing a refresh!
After removing all the neon tubes, they needed to be wiped down. Here they are freshly cleaned and drying on an old t-shirt.
Next, I made a bending pattern for the new tube. This is done by placing the broken tube face down onto a large sheet of paper, aligning the two broken halves together as best I can, then tracing around the glass with a marker.
Below is the only picture I took of the bending process, which shows part of the new piece aligned on the bending pattern.
After I bent up the new tube, I processed it (also known as “bombarding”). To do this, I attach the tube to a vacuum pump via a glass manifold and heat it to around 250°C (482°F) using a large electrical transformer. This heating process releases all the moisture and impurities inside the tube, which are carried away by the vacuum pump. When an ultimate vacuum has been reached inside the tube and the temperature is right for filling, I meter in the noble gas of choice (in this case, argon) and seal it off using a small flame torch.
Here is the tube on the processing table. The translucent, brown shapes you see in between the glass are pieces of mica, which prevent electricity from arching through to another section of the tube during bombarding. The small section of glass you see to the left of the neon tube with a bubble at the end is a mercury trap. It holds a very tiny amount of mercury, which gets added into the tube after the processing is complete, and will help the tube glow brighter after it vaporizes. Don’t worry! I never touch the mercury or breathe in any of the vapors.
After the tube was complete, I moved on to building a new panel to replace the thin plexiglass piece the neon tubes had been mounted to. Here it is on my bending bench (which often doubles as my assembly table) in progress. I use a PVC material called Sintra to mount neon to, instead of plexiglass, because it weighs less and I also prefer its matte finish, which I think looks nicer behind the glow of the neon tubes.
After touching up the block-out paint, I attached some tube supports to the panel to hold the neon tubes in place and wired everything to the transformer.
And here it is in all its glowing glory! A cherished family memento, refreshed and improved, to last another 30 years or more.
