I recently acquired an old 14 inch CRT monitor from a local buyer. It works fine, but I noticed a small annoying scratch on the screen. I did some reading and found some anecdotical evidence of people being able to fix these kinds of dents using cerium oxide powder (used to polish glasses etc) and an electric polish machine (drill / dremel). So, I decided to give it a try.
Disclaimers:
- I am _not_ an expert on this topic: don’t take this post as advice!
- Do NOT inhale cerium oxide!
- Wear safety goggles in case of your CRT decides to implode on you!
- Do NOT put too much pressure on the crt. Stop if things get to hot.
- Work in an environment insensitive to stains.
I started with putting masking tape around the scratch, and a cover around the working area, so the rest of the room would not get stained.
Then, I mixed the cerium oxide with water (I bought 10 gram from swedish eBay). I probably should have used less water during this step.
Then, I proceeded with dipping a polishing bit on my dremel tool in the cerium oxide + water blend. I also used a cotton swab and put a little of the mixture on the screen.
Now, for the procedure, I applied gentle pressure and relatively high rpm on the dremel. I took regular breaks and checked status of the scratch on a regular basis. It might be a good idea to practice on some other surface to find a good balance between pressure and performance. Nevertheless, in the end, the scratch went away. The whole procedure took about 10 minutes. I think a success factor was that the scratch was very light: I could not feel it with my finger nail. The only side effect is noticable if you look at the screen in a certain lightning, with a dark background, from the side: then it is possible to see that a part of the surface has been polished. From straight ahead, this is not visible though. What I don’t know is if the scratch was sitting in an anti-coating layer, which I polished away from this area, or if it was actually on the glass.
Overall I am very happy with the results. Now I use this monitor together with my Hyundai P5000M P200 MMX.
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