Removing scratches in your windshield / glass

There have been few comments on replacement windshields not being the correct thickness or dimensions as to OEM and all are pricey to purchase. In 1994, on the drive to Monterey, Dino 05702 proceeded through a mist in Seaside Oregon (mist in Oregon = summer heat wave LOL), turned on my wipers, the blade flopped over and started 3 long scratches. I immediately shut them down, but that takes another final wiping motion, so I had 2 wiper passes that left 3 scratches directly in the view of the driver.
No bueno.

Fast forward to last winter and I saw Steve Kouracos postings on polishing his windows to such a high level I thought I could do the same. A friend suggested a glass grind kit to try, here is my experience.

I first cleaned the windshield with spray away then followed with 0000 steel wool. I continued with Cerium Oxide polishing compound and although the tails are reduced by 50%, this reveals the deep portions that remain. Now we have our task target!

This is the BEST my glass has looked in years but still has some remaining scratches left, my fingernail hooks into all three.


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The kit comes with 3 levels of grind, I opt to start with the Medium grit, green pad on the drill mandrel pad attach point, then I covered the glass Identification "bug" with tape to protect it and started grinding. I want to be conservative and if that Med Green Pad is not enough, I can always return and use the more aggressive red pad if needed.

The goal is to produce a nice, even haze to the grind, just low enough to smooth out the scratch.

CAUTION: HEAT WILL BREAK YOUR GLASS. This is 45 yr old glass with pits and imperfections. The aggressive grinding pads will introduce the most heat in this process and you must be very careful. You do not want those thermal gradients high so always check by placing hand on the glass for a minimum of 30 seconds to get a feel for temperatures. If your hand can not stand 30 seconds on any location, you have too much heat buildup. Danger

The whole process took two hours and the majority of the time was waiting for the glass to cool.
I found it remarkable that placing my hand on the inside after short grinding time revealed almost the same temps as the exterior surface - heat is travelling across the laminate.

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After leveling the surface to remove scratch, I noticed lots of material had come off during the grind resulting in a final, even haze. You have levelled the scratch out, now to focus on clarity. Continue with less agressive final grind pad, Blue for Fine grind. Extend your grind area beyond the initial green pad zone and blend/feather in this finer grind. The affected area grows as you smooth the levelling surface and it appears just a little but more clear.
But you're not done yet


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The finer the grind, the longer it takes and remember to be mindful of glass temperatures inside and out.

Final step is the Cerium Oxide polish, this will take the longest in your effort but is the most important for final finish and Yes, you must wait a long time for glass to cool off.

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The scratches are out!



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Great result and I'm happy, so continue to polish the remaining windshield with Cerium Oxide. Great results with wonderful clarity.

Unfortunately, as in any case, the more you look then the more you find. This additional deep scratch was revealed dead center of windshield and was still evident after the prior final polishing so had to be bad. Yep, my fingernail hooks it. Let's start again, Green pad to a haze below scratch surface (lots of waiting time to cool), blue pad with larger smoothing area and final polishing to driver clarity

Note Green pad photo shows the Green pad has not finished yet as the scratch still remains. I continue using the green pad after the photo was taken.

The final result is so clear that I felt I had to point out where the original scratch was.
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Great points, thanks for the comments.
Yes, there are very fine marks and I will probably go back over them in the future but I do not see any barrel aberrations, steps, flairing, or starbursts at night. Clarity is fine and I don't see any focus interruption but then again, I had Clearplex on Dino 05082's windshield for 10 years and loved it at only 95% clarity and a quite bit of waviness. Said another way, when driving, my eyes focus is down the road and those close-in marks are out of my depth of field.

Because I know exactly where and what I did, then my eye knows where to look, but the casual observer doesn't have that advantage. A Concours judge would have spotted those wiper scratches, definitely would. You also noticed I started a grit grade below what would have worked and I took my time to go over it. Avoiding aggressing grit grades minimizes those marks and associated clean up

Grind time was not very long at all; two passes; first horizontal then vertical resulting in a layered box and then waiting 20 mins for cooling. The UK guys recommend spraying water but I want to avoid thermal shock and didn't like that idea.