Repair scratches on CRT glass?

Cerium oxide will get a lot of the small scratches, but the deep ones are hard to get out. Still, polished it up beautifully. Remember to have a water spray bottle handy to always keep the area you are buffering moist. I was careful on a crt, and it didn't burst. Wear safety goggles just to be safe though
 
I'm considering trying it on my SF Rush 2049 that has some scratches on the face of the tube
I did this over the weekend... I'm really happy with how it turned out, though I spent over 6 hours on it! I guess finding a replacement tube, doing a swap, and getting the yoke/rings adjusted probably would have taken at least that long, and it saves a tube from the trash.

The tube had deep scratches on the face... definitely looks like it was stored face down. It'd catch my fingernail when I'd run it across the scratches, and while playing, the game had the really annoying rainbow sparkly lines right in the middle of the screen. Now, there's just one very small line left over, and a few light scratches (I thought I got it all, but noticed these when I shined the flashlight on it... don't feel like spending a couple more hours getting it perfect though).

I used a Dremel Multimax with felt buffer pad and Cerium Oxide. I put a line of masking tape at the bottom of the tube to keep the liquid from dripping down into the game, and kept a rag nearby to wipe it off.

DogP
 

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Wow. That's amazing. Thanks for posting. Really good to know what's possible.

Is the cerium oxide a specific grit? And did you only use a single grit, or was it done in finer increments?
 
Wow. That's amazing.
That turned out awesome!
Thanks guys... I was actually a bit surprised how well it came out too. I was really hoping it'd at least just take the edge of the scratches and make them less noticeable, but I just kept going and eventually it cleared up.

Is the cerium oxide a specific grit? And did you only use a single grit, or was it done in finer increments?
I'm not sure if they make it in various grits or not, but this is the stuff i used: https://www.amazon.com/Gordon-Glass-Cerium-Oxide-Oz/dp/B007KOC19C . I thought that it may be like other compounds... starting as grittier stuff, then as it wears down, the grit get smaller to more of a fine polish, so I wiped the screen off and dipped my felt pad in the cup every few minutes to get fresh stuff.

I also briefly used sandpaper (progress was slow, so I thought I'd speed things up with sandpaper, then use cerium oxide to remove the scratches from the sandpaper)... I'm not sure how much it helped, though it certainly made new scratches on the screen. In the end, maybe it helped, though I should have been more careful on where I was sanding, since I spent a lot of time removing scratches from the sandpaper where there were no scratches to begin with. I used 120 then 240 grit, wet sanding (using cerium oxide slurry as the "wet", since it was convenient).

I also wore safety glasses, just in case of disaster. The tube got warm eventually, but not hot (I was careful not to stay in one place for too long, and to keep the pad wet).

The most important part was cranking up the music... it was a boring task, and the buzzing sound was annoying, so having good music helped. ;)

DogP
 
Got a link to the pad you used as well? Thx
This is what I used: https://www.ebay.com/itm/291284202654 . Just watch out... the felt pad will detach from the backing if you use the edge of the pad, or turn the speed up too high. When I used it on the car windshield, I had to use spray adhesive to reattach it several times. On the monitor, I was careful to apply firm pressure straight into the tube, and stayed at speed 6 and below... and it pad stayed on fine.

DogP
 
So my million dollar question is pressure....How much to apply when doing this fix....
 
So my million dollar question is pressure....How much to apply when doing this fix....
A lot... my arms were sore afterwards. :p I don't really think you're gonna hurt the tube from too much pressure... just pay attention to the sound of the tool (you don't want to burn it up) and how much slurry is being squeezed out of the pad, and you'll get a feel for how much to use.

DogP
 
for those worried about the tube imploding as you are applying pressure to the front, dont.

I've hit tubes with hammers straight on to demonstrate the strength of the glass on the front of them. It took several hits in or about the same spot to break the tube and when it did break it just fell in on itself.
 
for those worried about the tube imploding as you are applying pressure to the front, dont.

I've hit tubes with hammers straight on to demonstrate the strength of the glass on the front of them. It took several hits in or about the same spot to break the tube and when it did break it just fell in on itself.
Yeah, the face of the tube is very strong, but it also has a history of breaking due to heat. There have been several posts over the years of the front of tubes cracking if left sitting in direct sunlight. My (very remote, but only worry) was that the glass may crack if too much heat was generated in one spot, especially if a stress point was created from the scratch. But I was periodically checking how hot the tube was, and it never really got hot enough to worry.

DogP
 
Yeah, the face of the tube is very strong, but it also has a history of breaking due to heat. There have been several posts over the years of the front of tubes cracking if left sitting in direct sunlight. My (very remote, but only worry) was that the glass may crack if too much heat was generated in one spot, especially if a stress point was created from the scratch. But I was periodically checking how hot the tube was, and it never really got hot enough to worry.

DogP

direct sunlight is a completely different situation. I've seen that too.

Op I worked for used to leave stuff outside behind his shop. out of 50 or so monitors around 10 of them were piles of glass.
 
Well I order the parts of the links you provided. I have a glass bezel with a scratch that I'm going to practice on first before I try this on my 29" CRT monitor....
 
Well I order the parts of the links you provided. I have a glass bezel with a scratch that I'm going to practice on first before I try this on my 29" CRT monitor....
Cool... be sure to post how it goes! Be careful on the bezel though... that'll be much easier to break than the tube.

DogP
 
I did this over the weekend... I'm really happy with how it turned
DogP

Thanks for the info. I've used cerium oxide on glass but not on a tube. I have a 25" that has someone's initials under the bezel somehow, I'll give buffing it a try.
 
Aren't glass bezels tempered ? If so, localized heating/cooling, scratching, scoring, etc could all lead to a collection of glass 'pebbles'.

picture tubes aren't like that, and the faces are the strongest part. I'd keep heat (from friction due to abrasives/etc) from building up, but I'd think otherwise it likely should be fine.... but bear in mind I've never tried it.

Though I am quite interested in how it works out.

wonder if clear nail polish/etc could be used as a filler for those that don't want to take cuting/polishing compounds to their picture tubes ?

what about whatever is used for windshield repair for chips/scratches ?
 
to those worried about heat, dont so much.

When we rotate games in the death heat of the summer the screens/face of the CRT's get so hot that you cant leave your hand on them for a very long time.

My point is, if the sun cant "easily" break a bezel or a CRT some rubbing isnt going to do squat.

Now I'm not saying that heat cant break these things as I've seen it happen.
 
I'm referring more to 'localized' heating. Tempered glass is under lots of internal stress.

Enough of a temperature differential of heating/cooling vs the rest of the panel, and *boom*.

(an example, hot water onto a cold plate of tempered glass (lets say for example a fridge shelf))

If localized abrasives create too much heat that would be my concern. You might have to overdo it to create a problem. Its more something to be aware of.

Tempered glass has been known to simply 'let go' due to some imperfection triggered by thermal changes, vibration, pressure, etc.

I'll be following along though, as I have a nice 100 degree tube for a WG 6100 that has a few small scratches. They probably don't show (monitor has not been built yet), but it would be nicest to remove them. (tubes aren't tempered, so there is no risk of instant glass pebbles.... .but I do believe bezels, pinball playfield glass and bezels,etc are all tempered).
 
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HOT water is one thing. Rubbing is another. Unless you are using a high speed buffing tool of some sort I dont think anyone can get a piece of glass HOT enough FAST enough to make it explode.
 
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