Kestrel Posted March 28, 2022 Share Posted March 28, 2022 Has anyone successfully buffed or polished out a fine scratch in glass ? An unsecured metal garnish clip scored a long but fine scratch in my car's passenger window glass when I rolled it up after installing new trim pad and garnish moldings. I see many DIY kits on-line that claim to remove scratches. It looks possible but requires patience and elbow grease. Thanks all ! Link to comment Share on other sites More sharing options...
Restorer32 Posted March 28, 2022 Share Posted March 28, 2022 If you can catch the scratch with your fingernail it likely cannot be buffed out. 1 Link to comment Share on other sites More sharing options...
Restorer32 Posted March 28, 2022 Share Posted March 28, 2022 Easier to just have a new piece of safety glass cut. 1 Link to comment Share on other sites More sharing options...
Bhigdog Posted March 28, 2022 Share Posted March 28, 2022 Like R32 said if it catches your fingernail it's kaput. If you want to try polishing here's what worked for me.......Bob If the scratches will "catch" your finger nail the glass is toast. If your finger nail will slide over the wiper marks they are, with patience, repairable. Below is a post I submitted in 2010 detailing how I successfully removed wiper marks from my 56 Chrysler wind shield. I will add that this will not remove the micro pits that every windshield picks up over time but will restore your glass to quite usable condition...................Bob In the interest of sharing knowledge............ I'm finally getting around to installing the glass in the 56 Chrysler. I've been fretting about the windshield and the wiper marks in it for two years now. The "marks" were not quite deep enough to actually "catch" a finger nail but they could be felt. Imported repro glass is available for about $650 without a date code. I'd heard both pro's and cons about polishing out the scratches. I'd heard that it can't be done, that it would cause distortion because it would leave a shallow hollow where the groove was or heat build up would crack the glass. Being both a frugal type and having nothing to lose I figured I'd give it a try. First I needed a polishing "kit". I looked at ready made kits and saw they were nothing more than a hard felt pad and some cerium oxide polishing compound. So instead of p**sing away $75 bucks on a kit, I cut down an old backing disc from my DA sander to 3 1/2" diameter and epoxied a 3/8" thick pad of hard felt on the bottom. My local glass shop sold me a baby food jar of cerium oxide for $5. So now I had my kit. The kit sellers say to chuck their pad in a drill to polish out the scratches. I figured that was the cause of the distortion problem. Folks were using the pad like a disc sander and concentrating on the scratches. To get around that I mounted my pad on my DA sander and used it only on the orbital mode. Also, instead of concentrating on the scratches I evenly buffed the glass and only gave the scratches a bit of extra buff time. I'd also heard that the glass could crack from heat build up. Not true. I mixed the cerium oxide with water to make a loose paste. Wet the pad, spread a bit of paste, and started buffing VERY slowly and lightly. As long as everything is wet there in no heat build up. I kept a spritz bottle of water close by and just kept spritzing, buffing, pasting, spritzing buffing and checking. In about an hour all traces of the scratches were gone, there was no distortion, and I'd saved almost enough to pay for the new tires for the 56 that I need to order. The whole project took a morning to do including making the polishing pad. If you decide to try this here's few hints. The hard felt is available from McMaster-Carr by the square foot. Or, I have have enough left over to cut a disc for someone or two or three. Keep the glass wet and keep the orbital speed about mid way. Draw a line under the scratches, with a magic marker, on the back side of the glass. That way you can find them and you only have to wipe a small area clean to check your progress. Do not let the pad get dry. It will pack dryed oxide into the micro pits that are in every used windshield and you will spend an hour with soapy water and a tooth brush getting it out. Do not ask how I know this last bit...............Bob Edited April 18, 2010 by Bhigdog (see edit history) 1 2 Link to comment Share on other sites More sharing options...
joe_padavano Posted March 28, 2022 Share Posted March 28, 2022 Here's how Fisher Body tells you to polish scratches in glass. Link to comment Share on other sites More sharing options...
Kestrel Posted March 28, 2022 Author Share Posted March 28, 2022 The scratch is approximately 10" long from top to bottom of the window. I just ran my fingernail across it and it only "caught" in a couple of places, those being an inch or so long. Based on the responses, I think I can polish away most of the visible damage using the cerium oxide buffing technique. I have piece of "test" glass to practice on first. Not looking for a 100% perfect job but I feel much better thanks to the replies and Bhigdog experience ! I was so anxious about re-installing the newly painted garnish parts and upholstery pads, I failed to notice that silly metal garnish molding clip out of position that isn't really necessary anyway. Link to comment Share on other sites More sharing options...
Bhigdog Posted March 28, 2022 Share Posted March 28, 2022 Good luck. Mask/cover everything the cerium oxide paste flys every where..........Bob 1 Link to comment Share on other sites More sharing options...
nickelroadster Posted March 29, 2022 Share Posted March 29, 2022 You might be able to get the scratch out but it could also leave a distortion in the glass that may look as bad. A new glass would not be that expensive. Link to comment Share on other sites More sharing options...
avgwarhawk Posted March 29, 2022 Share Posted March 29, 2022 Attempt to polish out the scratch. Prepare to buy a new replacement if it does not work out. Let's us know how it goes. 1 1 Link to comment Share on other sites More sharing options...
Leif in Calif Posted March 30, 2022 Share Posted March 30, 2022 I worked in the glass industry for 45 years, 10 of them with Pilkington (formerly known as LOF) everything above is true, but it takes a tremendous amount of polishing for even the lightest scratch and really makes a mess. Also, you absolutely can break the glass if it gets locally too hot. As long as there's some moisture present you are OK. Even heavy scratches can be removed but you'll be at it for days, and they will be distortion in the glass when you're done because the surfaces will no longer be parallel. 1 1 Link to comment Share on other sites More sharing options...
Kestrel Posted March 31, 2022 Author Share Posted March 31, 2022 Thanks Leif for the tips. I have cerium oxide and some felt wheels coming so I'll give it a try. Good to know about the moisture. Being a passenger side window I don't worry about distortion too much. I'd attempt to yank the glass out and replace with new but, darn....I just re-installed my newly upholstered ($$$) door trim pad. To remove it and line up all those nails again while trying not to do any new damage makes me a nervous wreck. 😬 1 Link to comment Share on other sites More sharing options...
Leif in Calif Posted March 31, 2022 Share Posted March 31, 2022 That new upholstery looks terrific! In polishing my own stuff, I've found the appearance of the scratch gets better as my acceptance of it gets easier (due to fatigue) until I'm "done". 1 Link to comment Share on other sites More sharing options...
Bhigdog Posted March 31, 2022 Share Posted March 31, 2022 7 hours ago, Kestrel said: I don't worry about distortion too much. If you concentrate on the scratch you will get distortion. If you do get it, it will nag you forever. Take your time, lots of it, and polish a wide area around the scratch. That said, and looking closer at the scratch, I think you are looking at replacing the glass. I hope I'm wrong.........Bob Link to comment Share on other sites More sharing options...
Buick35 Posted March 31, 2022 Share Posted March 31, 2022 (edited) 8 hours ago, Kestrel said: Thanks Leif for the tips. I have cerium oxide and some felt wheels coming so I'll give it a try. Good to know about the moisture. Being a passenger side window I don't worry about distortion too much. I'd attempt to yank the glass out and replace with new but, darn....I just re-installed my newly upholstered ($$$) door trim pad. To remove it and line up all those nails again while trying not to do any new damage makes me a nervous wreck. 😬 I used cerium oxide on my son's 66 mustang windshield and it came out pretty nice. I bought a kit on line that came with the powder and buffing pads. I can't remember who sold it.Greg Edited March 31, 2022 by Buick35 Spelling (see edit history) Link to comment Share on other sites More sharing options...
Kestrel Posted April 1, 2022 Author Share Posted April 1, 2022 As I mentioned above, most of the scratch line does not catch my fingernail. So maybe I have a chance. Good tip to polish a wide area rather than concentrate on just the scratch. I don't whether to have a beer before or after the operation. Link to comment Share on other sites More sharing options...
Kestrel Posted April 15, 2022 Author Share Posted April 15, 2022 Conclusion ! After a few hours of polishing away over 2 days with a felt wheel and cerium oxide, I'm done. Afraid to crack or distort the glass I stopped before risking collateral damage. The crack is definitely less severe with more muted, blurred margins , but still noticeable to the discerning eye, but I can live with it. I therefore deem the project over. My electric drill heated the glass up to 120 degrees at times along the crack. I prudently decided to cut my losses before it shattered or distorted. Masking off the door and everything else took almost longer than the polishing 😀 Thanks again for all the tips and guidance. 5 Link to comment Share on other sites More sharing options...
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