Windshield repair gone wrong

[chuckk]

Ok so here it is I had some pretty big scratches on my windshield due to my passenger wiper. I decided to look around for a glass polishing kit.

I ended up using the Eastwood kit (Pro Glass Polishing Kit for Deep Scratches (http://www.eastwood.com/glass-polishing-kit-for-deep-scratches-5658.html)
The problem is, I can't find a way to take out the swirls induced by the abrasive disks. I have followed the procedure thoroughly but it seems that the compound is not strong enough. It took the haze out but thats it.

I even used my rotary to be sure I was at the right RPM.
Any solution to this...of course Im prepared to change the windshield.

[Setec Astronomy]

Which color disk caused those swirls? Did you use all three? In what order?

[chuckk]

I always try least aggressive first and then move on. In my case I had to use the corse disk. Then, I followed up with the medium and the fine. All three disks were used.

[Setec Astronomy]

I always try least aggressive first and then move on. In my case I had to use the corse disk. Then, I followed up with the medium and the fine. All three disks were used.

I had actually seen that system somewhere else and I would like to try it some day; I didn't realize Eastwood sold a version of it.

But here's the thing, where I saw it, it's set up as a 5-disc system. The ones you have are 35 micron (coarse, green), 10 micron (medium, blue), and 5 micron (fine, orange). However there is also a pink which is 20 micron, and a 568XA white polishing disc that would be used instead of that tub of glass polish.

The other thing is 3M calls these discs "Random Orbital Microfinishing Discs", so I wouldn't use them with a rotary or drill (not just because that's the name, but because for this application you don't want to use a rotary or a drill...there's a reason they make random orbital sanders (which spawned the car polisher business when people adapted the Porter Cable sander to car polishing).

So, I think one of three things happened:

1. This system sucks and you can't get good results out of it.

2. Using a rotary caused gouging of the surface.

3. By skipping the 20 micron there were sanding marks from the 35 micron the 10 just couldn't get out.


Might be time to call a pro glass polishing place, or have the windshield replaced if it's got a lot of other problems.

http://multimedia.3m.com/mws/media/694375O/3mtm-abrasive-systems-random-orbital-abrasive-disc-portfolio.pdf?&fn=61-5002-8285-2.pdf --268XA and 568XA

[GSKR]

I like option 4'please.

[Paul A.]

I have found windshield glass properties to be similar to paint and clearcoat properties with regard to hard vs. soft. My Pilkington brand BMW windshield is very soft. My wife's Nissan windshield is harder (PPG?). I attempted to cut her wiper "tracers" down and used ceriglass and a LC glass pad. No problem. Came out great.

I then tried to do the same on mine and scoured the crap out of it. Doh!!! I then resorted to my rotary, a hybrid orange pad and ceriglass. Bam! Much much improved and scratches removed. I will admit to working it a lloonngg a** time and frequent water spritzes to keep it wet but the results were phenomenal.

Interesting little lesson...least aggressive is my new approach to windshields now too!

[Setec Astronomy]

I have found windshield glass properties to be similar to paint and clearcoat properties with regard to hard vs. soft.

Yeah, it's funny IME the Asian mfr's glass seems to be really soft, the Hyundai's are ridiculous, in fact Todd Helme posted a glass polishing thread like a hundred years ago on his wife's Hyundai down there in FL with horrible wiper trails (and no winter road grit to do it...although maybe beach sand).

I have really been intrigued with this approach of sanding the windshield (especially after I machine sanded some headlights recently and went all the way up to 5000 grit, then polish and coat), but the idea of hazing your windshield with the first coarse pass is really a pucker moment about whether you'll be able to bring it back.

[Paul A.]

Yeah, it's funny IME the Asian mfr's glass seems to be really soft, the Hyundai's are ridiculous, in fact Todd Helme posted a glass polishing thread like a hundred years ago on his wife's Hyundai down there in FL with horrible wiper trails (and no winter road grit to do it...although maybe beach sand).

I have really been intrigued with this approach of sanding the windshield (especially after I machine sanded some headlights recently and went all the way up to 5000 grit, then polish and coat), but the idea of hazing your windshield with the first coarse pass is really a pucker moment about whether you'll be able to bring it back.

Hahaha! Pucker is an understatement to my reaction to seeing what i did to MY windshield!!! After all, i was using Mrs. Puckman's windshield as i always do...lab rat duty...and thought "ok, i got this". The Detailing Gods said "oh, you think so?"

BTW, i DO NOT like the LC glass pad and will be ordering some Car Pro pads. More cushion for pushin'.

[SameGuy]

Don't most of the auto glass specialty companies like GlasWeld offer kits precisely for polishing glass based around the water-fed sanders from Fein and Flex? I think there's a lot more to abrading glass than one of the (relatively) inexpensive kits with sanding discs and polish. The most I'm prepared to try without truly specialized tools and supplies is CeriGlass and Rayons on a DA.

[Paul A.]

I wouldn't doubt that, Francesco. And i'm with you on taking a step back and really thinking about what i'm doing here. I will say, though, i was very impressed with the results i got with CeriGlass and my rotary.

Maybe Menzerna can come out with a Diamond Dust GF-6000!

(nevermind. Just thought of just the 8 oz. cost of THAT)

[SameGuy]

Hehe true

[Setec Astronomy]

Hahaha! Pucker is an understatement to my reaction to seeing what i did to MY windshield!!! After all, i was using Mrs. Puckman's windshield as i always do...lab rat duty...and thought "ok, i got this". The Detailing Gods said "oh, you think so?"

BTW, i DO NOT like the LC glass pad and will be ordering some Car Pro pads. More cushion for pushin'.

Oh, I missed that, yeah those LC pads are terrible for some reason, stick with the Griot's or CarPro.


Don't most of the auto glass specialty companies like GlasWeld offer kits precisely for polishing glass based around the water-fed sanders from Fein and Flex? I think there's a lot more to abrading glass than one of the (relatively) inexpensive kits with sanding discs and polish. The most I'm prepared to try without truly specialized tools and supplies is CeriGlass and Rayons on a DA.

Yeah, the "pro" way to do it is with a water-fed rotary, I usually do glass polishing with a rotary and a spray bottle. My intellectual problem with this approach is that it's kind of like trying to do a compounding job on paint using a finishing pad and a polish, rather than a wool pad and a compound or wetsanding first.

The substrate is so hard on windshields it kind of begs for a more aggressive approach, like sanding. If I wasn't invested so heavily in backing plates and glass pads, I would have already tried the sanding, and I am pretty sure I am going to do it at some point just because it would be so much more efficient than polishing.

The investment is in a couple sizes of backing plates (for the pressure sensitive adhesive discs), and an assortment of discs in the various grades and sizes, and you have to adapt the backing plates which are for rotary to DA. Not too many places to buy this stuff either, 3M sells them in large box qty's, so you have to find some place that breaks the boxes or it would be really expensive to test this.

[chuckk]

I had actually seen that system somewhere else and I would like to try it some day; I didn't realize Eastwood sold a version of it.

But here's the thing, where I saw it, it's set up as a 5-disc system. The ones you have are 35 micron (coarse, green), 10 micron (medium, blue), and 5 micron (fine, orange). However there is also a pink which is 20 micron, and a 568XA white polishing disc that would be used instead of that tub of glass polish.

The other thing is 3M calls these discs "Random Orbital Microfinishing Discs", so I wouldn't use them with a rotary or drill (not just because that's the name, but because for this application you don't want to use a rotary or a drill...there's a reason they make random orbital sanders (which spawned the car polisher business when people adapted the Porter Cable sander to car polishing).

So, I think one of three things happened:

1. This system sucks and you can't get good results out of it.

2. Using a rotary caused gouging of the surface.

3. By skipping the 20 micron there were sanding marks from the 35 micron the 10 just couldn't get out.


Might be time to call a pro glass polishing place, or have the windshield replaced if it's got a lot of other problems.

http://multimedia.3m.com/mws/media/694375O/3mtm-abrasive-systems-random-orbital-abrasive-disc-portfolio.pdf?&fn=61-5002-8285-2.pdf --268XA and 568XA

Actually I used my drill for the sanding and then I couldn't get the hazing out with it and decided to re-do everything with my rotary...I thought it would be a more precise approach.

Im not sure if I want to go ahead and try the 3M products...At first I wanted to try the eastwood kit thinking I could offer the service in the future. Who wouldn't want a brand new windshield for a few bucks?! right? Lesson learned it's just so much work, Ive spent literaly half a day trying to polish it. It's not worth it.

Moral of the story for me would be: if you can't take the scratches out with a heavy foam pad/glass polish then leave it alone...Im just happy that this mistake was on MY car.