Introduction: Fixing an Old Advertising Clock
I found this old advertising clock in a junk store in New Mexico. The case of the clock had quite a bit of paint spattered on it, and from the condition of the wiring I was unable to test it. But the price was right, so I took it on as a project.
Step 1: Disassembly
The case was made in two halves which were held together by four sheet metal screws. I removed the screws, then had to pry the halves apart with a putty knife because they were also glued together with some sort of rubber gasket.
Once the halves were separated (photo 1), I carefully pried the clock hands free (photo 2), and un-clipped the remains of the neon light tube (which was broken, of course).
Next, I flipped the base over and removed the old clock motor and gear assembly and the transformer for the neon light (photo 3.
Step 2: Identifying the Problem(s)
This clock had some big problems. The neon light tube was broken and the electric clock motor was burned out. I took the motor apart in an attempt to fix it, but it was beyond repair.
The clock motor could be replaced with a quartz motor, but replacing the neon tube would cost much more than the clock was worth. So, I took a slightly different approach in replacing it.
Step 3: Replacing the Clock Motor & Light
Installing a new quartz clock motor was a simple process. I made a rubber shim to put between it and the case, and simply fastened the new motor in place with a shaft nut. The clock motor is shown in photo 1.
To replace the circular light, I first considered replacing it with a fluorescent circular light. After all, the neon tube was 12 inches in diameter and 12 inch circular fluorescent tubes are readily available (along with ballasts), but I was concerned that the fluorescent light would be much too bright for the clock. So, I took another path.
I found a 3 foot rope light that just happened to fit inside the case by making two complete loops (photo 2). This would provide sufficient light to read the clock dial, but not so much that it would be blinding.
Photo 3 shows the new clock motor installed along with the rope light and power cord coming out of the back side of the clock base.
Step 4: Cleaning the Case
Before reassembling the case, I had a lot of paint to remove. It seems to me that the wall this clock had been mounted on had been painted at least twice (without anyone removing the clock!). It had both latex and oil based paint all around it.
The latex paint removed easily with dried latex paint remover. The oil based paint, however, required tedious scraping with a razor blade. After all paint was removed, I polished the case with a metal polish.
Step 5: Putting It Back Together
Putting the clock back together was relatively simple. I installed the hands onto the new clock motor and screwed the two halves of the case back together.
The total cost of repairing this old clock was $5 for the quartz clock motor and $8 for three feet of rope light. The tools and supplies used were minimal: a screwdriver, pliers, scraper, razor blade, and some metal polish.
As you can see from the photo, I apparently finished this project at exactly 5:14, just in time to get cleaned up for the evening meal!