I have an RCA CTC-9 that I will eventually finish restoring. When I got it, it had a brightener on the 21CYP22. It measured zero emission on the Sencore. I had gotten a car load of used CRTs some time ago from a guy near here. Many were weak and have since gotten the deep six. One tube that I had I knew was a color. No numbers on it but it was identified from pictures as a 21CYP22 because of the anode locations etc.

So, I rebuilt the power supply capacitors, and installed the used CRT. It has a good bright raster but needs the rest of the obvious work done. When I cleaned the face of the tube, it has a couple scratches on it. Yes, I know it could lead to failure there. But this set has a good safety glass in place.

My question (finally cut to the chase :D ) is this: Does anyone know of a good fix to fill the scratches? Is there a car windshield epoxy type of stuff like the windshield guys use? Or could one fill them with epoxy and then polish it out?

Didn't know if anyone has had experience with doing this.


Thanks in advance!

Does anyone know of a good fix to fill the scratches?

For shallow scratches or rubs that show mostly when the set of turned off, this trick works very well and is easily reversible, and will probably have to be done again the next time the CRT is cleaned.

It takes all of five minutes to do:

Simply clean the face of the CRT and apply paste wax (either floor wax or car wax), and lightly wipe it off. Wait overnight, and then with a soft cloth buff it out.

Back in the 1950's we routinely did this to each and every rebuilt CRT that we sold and never once had a customer spot it.

Jas.

If they are deep scratches, you could use an epoxy, but I would squeegee most of it off before it hardens, use a razor, or an actual squeegee. Maybe even air plane glue in a tube, or finger nail hardener, I stole a bottle from the wife one year to fix a broken crystal in my watch, flowed into the crack pretty good, better than air plane glue.

There is even clear coat stuff for finger nails, you put over the color polish. Go to youtube and look for the different finger nail hardeners, they have a movie for everything now, and the people usually rate the stuff they use, so you can go into the nail department and look like a pro-! Ha!

Is it noticable with pictures on the screen? If not, leave it be.

Thanks for taking the time with all of the replies. It is more noticeable when the tube is off but being somewhat anal and knowing it is there, I see it. I will ponder the advice above and see what I can do.

Thanks for the help!

Is it noticable with pictures on the screen? If not, leave it be.
I second that. There's a small scratch on my Panny screen, didn't notice until I got really close to it. I'm not doing anything to it. Don't want to turn scratches into blotches.

Never did it but I have heard tooth paste works good.
Whatever its probably best to do a junk jug first, matters may be
made worse. Also consult a telescope making site. The
mirrors have to be figured perfectly starting with coarse the
ever finer work. Much more accurate than a TV would ever need.

73 Zeno:smoke:

You can use one of those round sanding grinding pads that go in a hand power drill. Start with 240 grit and work up to 330. Keep the sanding pad moving, don't stay in one spot. Take your time, glass will heat up. When completed, let it cool.
Now use a polishing pad on the drill. Mix cerium oxide powder with some water, mix to a lumpy paste. Pour some on tube face and start polishing. Keep a spray bottle of water around and spray polishing head with it when the polishing compound begins to dry out. Take your time, glass will warm up a little.
It's menial work, should take about 2 hours for small scratches.