Restoring Plastic Gauge Faces
By Keven Coates
Do you have any plastic gauge faces that have become so hazed by sunlight or so scratched up they are unreadable? Ten minutes and some auto parts store rubbing compound may be all that's needed to make your gauge functional again.
In my case, I had a portable air tank used to fill up my tires. It served me well for 20 years but, being plastic, the gauge had become so scuffed and scratched it was getting hard to read.
I wondered if very fine abrasive would be able to remove the scratches enough to read the gauge face again. I used some rubbing compound, which you can get at any auto parts store and even some department stores. It's a very fine abrasive, made specifically for paint or plastic, designed to remove tiny scratches. I was concerned it would cause more haze than clarity, but I didn't have much to lose, so I tried it.
I put a tiny bit of compound on a rag and rubbed it onto the gauge face. I rubbed for about a minute, hoping that, while I couldn't see what I was doing (since the compound smears on the gauge face), I was sanding the scratches out. Then, I took a dry rag and wiped it all off. It was amazing! I could read all the numbers on the gauge face! It wasn't pristine, but it was definitely far more readable.
I think with careful application using a slow speed buffer (2,500 rpm or less) and a finish polish with polishing compound (finer abrasive), the gauge could have looked like new; for my needs, it was perfect as it was.
I used this trick on my lawn mower amperage gauge. It’s been sitting in the sun for 15+ years and was hazed beyond recognition. Now it's actually readable! I also tried it on an old multimeter face. It worked great! Be careful though, some of those old gauge faces will be very brittle and may crack easily.