Removing scratch from glass / polishing glass.

[MikeDVB]

So...

I came out to my car today at Lowes and noticed somebody had put a pretty deep gouge in the top of my passenger side window... Not sure how - nobody was parked next to me when I went in or when I came out and I was inside all of 10 minutes...

I took some 400 grit sandpaper and managed to get the scratch itself out and feathered the glass to the untouched glass around - you can tell that there was a deep scratch if you look closely but it's near the top rear of the window so it's not a huge deal.

I worked my way up to 2,000 grit sandpaper wet sanding and the glass feels smooth to the touch but you can obviously still see the little swirls from the sandpaper.

That said, I'm a bit of a perfectionist... I'm going to take some glycerin+water+jewelers rouge and try and polish out the fine scratches left by the 2,000 grit sandpaper. From what I've read it should work well - but I wasn't sure if anybody here has repaired scratched glass/polished glass before that may have some advice. I'm not above and beyond replacing the glass itself [which is why I've no issues trying to repair it] but would like to give polishing it up back to a smooth finish a try before giving up on it.

Any input/thoughts/suggestions are appreciated. The area that needs polished is maybe 2 inches by 4 inches [as I had to feather the scratch out, it was fairly deep].

 

[jerryv]

I've never done that to glass, but I've built some musical instruments, and the next step after 2000 grit wet sanding would be rubbing compound, and then follow that with 'scratch and swirl remover' .. which should bring it to a gloss. You can find both in an auto parts store. Good luck.

 

[MikeDVB]

I used rubbing compound and then polishing compound but the scratches that are left are super-fine. It's almost as though the glass is 'too hard' to polish properly with normal materials for points.

I'll post up my results when I get the rouge tomorrow. Going to have endodontic surgery in about an hour and a half so not sure how soon I'll feel like messing with this heh.

 

[Mr. Habib]

You might some Flitz or Simichrome. I haven't tried either one on glass, but they both work well on other things.

 

[jerryv]

I used rubbing compound and then polishing compound but the scratches that are left are super-fine. It's almost as though the glass is 'too hard' to polish properly with normal materials for points.

I'll post up my results when I get the rouge tomorrow. Going to have endodontic surgery in about an hour and a half so not sure how soon I'll feel like messing with this heh.

It may be you didn't do one of the abrasive steps quite enough. Polishing is the art of removing big scratches with smaller and smaller scratches, until they're undectable. If you didn't go quite far enough with (say) 1500 grit, it will be very hard to get a good result at 2000 grit.

FWIW, I think you can get sandpapers up to 4000-5000 grit. Could be hard to find it though. The rouge might work too ..

I never felt like doing much after endodontic surgery. Good luck .. I hate the dentist's chair ..

 

[BustaN3T]

A Big Hammer then Call Safelite...seems to be the easiest way...if it is the side window junk yards carry all kinds of windows......and they are easy to replace...

 

[AD Marc]

Glass polish and a proper pad on a DA buffer will do the trick.

 

[MikeDVB]

What's special about a "DA Buffer"?

I have no issues spending some time to get this nice and clear even if it means going back to the rougher stuff and working my way up. I did it initially all by hand and it's not very even but haven't been able to figure out a way to do it evenly. I have 3" buffer pads and things for my drill but no good way to sand the glass beyond hand that I can think of.

 

[nmcqueen469]

Cerium Oxide is what you need to effectively repair scratches in glass.

It's nasty, messy stuff but that's typically what it takes.

I sell car polish for a living and even the most aggressive polish we make won't touch a scratch in glass, unfortunately.

 

[MikeDVB]

The jeweles rouge is ferric oxide as I understand and should do an ok job with enough effort. If not, I'll look at cerium oxide. I could replace the glass easy enough but this is a learning experience for me. Anytime I can repair instead of replace I'm happy.

Once this is done, I'll have a good feel for how to do it again if needed.

That said, can one get by with a buffer pad on a drill or does a "da buffer" do something special?

 

[perry]

On glass, the drill should be ok. The dual action (DA) polisher is like a random orbital buffer so you aren't hitting the same spot if you hold it still. On paint, you can burn right through it.

Dual Action Orbital Polisher Guide: how to remove swirls, scratches, & oxidation with an orbital buffer. Porter Cable 7424, foam pads, backing plate,

CarPro Ceriglass Glass Polish, windshield polish, water spot remover

 

[MikeDVB]

Ah ok. Not super worried if it doesn't turn out perfect - I mean even as-is it's "ok" but I really would like to get rid of those fine scratches!

Where I removed the deep scratch you can see visible distortion in the glass so if I'm going to spend more time on this I may as well start rough and work my way back down to something fine and feather that dip out a bit.

I appreciate the help.

 

[nmcqueen469]

Yep, stick with a drill or a hi speed rotary if you are working with glass. It's SOOOO hard compared to automotive clear coat that even a DA Polisher won't do much, even with a very strong compound.

 

[MikeDVB]

Yep, stick with a drill or a hi speed rotary if you are working with glass. It's SOOOO hard compared to automotive clear coat that even a DA Polisher won't do much, even with a very strong compound.

I was doing fairly low RPM (1,000~2,000) to avoid two things: 1. Breaking down the polish too fast due to heat 2. Slinging polish everywhere .

Any tips/suggestions are certainly going to be taken into account and very much appreciated.

 

[nmcqueen469]

I was doing fairly low RPM (1,000~2,000) to avoid two things: 1. Breaking down the polish too fast due to heat 2. Slinging polish everywhere .

Any tips/suggestions are certainly going to be taken into account and very much appreciated.

Breaking the polish down is the name of the game, that's what makes it work. Get it spread out evenly and slowly so you can avoid slinging, then wind it up and let 'er rip!


Here's one of our videos for scratch removal using 4" pads on a drill. Basic process is the same on glass as it is on paint.

Adam's Polishes - Scratch Removal with 4" Focus Pads

 

[MikeDVB]

Breaking the polish down is the name of the game, that's what makes it work. Get it spread out evenly and slowly so you can avoid slinging, then wind it up and let 'er rip!


Here's one of our videos for scratch removal using 4" pads on a drill. Basic process is the same on glass as it is on paint.

Adam's Polishes - Scratch Removal with 4" Focus Pads

Thank you so much for all of your help. Admittedly I've never done body work/paint work before so while I understand what polishing is supposed to do, I have no experience actually doing it.

This is a great learning experience for me across the board!

 

[nmcqueen469]

Happy to help! Poke around through our videos if you have some time to kill...good info in those!

If you are so inclined to buy anything, PM me first. I can save you some money.