Polishing out rear window scratches - Very time consuming

[cmayna]

Didn't think I would have actually taken this project on, but with years of buffing the helmet under my belt, how tough can this be?
 :craz

Besides since I recently finished polishing out both front and rear window trim pieces to a wonderful finish, maybe this new project wouldn't be too tough.

Well this is extremely time consuming to say the least.  After watching my glass guy polish out some scratches on another piece of glass, I recognized the compound and pad as having come from Eastwood products.  Because this compound only polishes the scratches, not necessarily removing them, I needed to look further into actually removing some deep scratches.  Eastwood also sells the deep scratch kit, which contains the polishing kit as well.  The deep scratch kit has 3 different grade abrasive pads which is used to literally sand the scratches out.  You want to start out with the finest grade pad possible to remove the scratches.  If it doesn't work go to a coarser grade.  Once the scratch cannot be felt by your finger nail, step up to the next finer grade pad and finish off with the finest pad. The most important thing is to have running water constantly flood the area to keep the glass cool.

Here's my temp booth which helped prevent the polishing compound from flying all over the yard.  Glass in place.  Note the black circle I marked with a sharpie pen on the bottom side of the glass, circling the area I wanted to address.   This is a must especially when you start using the polishing compound:





Here's a pic using my variable speed polisher set at 800-1200 rpm with water running:




Here's a pic of the fogged area caused by the abrasive pads.  As you can see I did go outside the black circle attacking neighboring scratches.  Keep in mind, the more you scratch, the more fog you need to polish out:




Polishing out the fog using the special pad and compound at a speed of 1200-1500rpm.  This is when having the black circle helps.  Some use bright colored crayons.




What..... you want videos too?

[Horseplay]

As something coming up on the to do list you're timing with this is good for me. Thanks. Of course, it would help if you could show the results as in a before and after shots. Did it turn out well? Get the offending scratches out? Anything about the products or process you found lacking? I'll shut up now.

[cmayna]

I can't imagine doing this to a glass that's installed already.  That would be a big mess.  My goal was only to get the dominating scratches out.  There are still some scratches remaining but nothing I can't live with.  I had to draw the line when to stop.  I estimate it took me 3 hours.

I thought before and after but working under an oak tree, the reflections of such makes it very tough to see especially when taking a pic.

This particular piece of glass is not Shag's original one but another one I got pretty cheap from Craigslist.  It had far less and shallower scratches than Shags.   I still might consider taking on Shags original glass that has some major  but very few very deep scratches, just to see if I can do it.  I even have a 3rd piece of glass which I might take on but it has so many scratches all over the place, I could see 10-12 hours +.

Go to eastwood.com and search for the deep scratch kit.    Wear a mask when using the abrasive pads for this mess puts off some nasty stuff you don't want to get in your lungs.
Prepare for a big mess.  Wear an apron, etc.

[70_Fastback]

Wear an apron, etc.

Just like in your kitchen....   :vic

[Midlife]

Go to eastwood.com and search for the deep scratch kit.    Wear a mask when using the abrasive pads for this mess puts off some nasty stuff you don't want to get in your lungs.
Prepare for a big mess.  Wear a mankini, etc.

Fixed it for ya.

[cmayna]

Oh of course.  Much easier to hose yourself off afterwards  :craz

[GTchris]

Great post, thanks for the updates!

[GTchris]

Great post, thanks for the updates!

I am retracting this statement. I wish you never posted this and gave me the idea to try this. After seeing this post I decided to give this a go. 

I had a few scratches on my windshield and figured I would try this out on that piece of glass rather than the back since it is the least expensive if I screw it up. Well, after spending $100.00 on materials and the better part of 8 hours Saturday, the windshield is still not done, I have decided I should have probably done my back a favor and just bought a new windshield. Getting old sucks.

My back glass does not look to bad and I am really hoping that it is not going to take as long to get through. I could see spending this kind of time working on the back glass but, the front, probably not.

The discs do not last very long, I have gone through 3 of the medium and you can still see traces of the deepest scratches. I had about a dozen scratches that I was dealing with including a mark that looked like it was made by a badly worn wiper blade. Apparently Eastwood does not sell the "deep" scratch pad any longer so, if you have deeper scratches you just have to work at it a bit longer with the medium pad.

[SAC69]

Craig, the reason it's so time consuming on your backglass is because it's tempered glass, unlike the untempered windshield.  It's my understanding that generally it's extremely difficult, if possible at all,  to remove scratches on tempered glass.  (I've never personally atttempted to polish tempered glass but rather am going off info I've had to deal with on newer cars.)

[66benchcoupe]

but with years of buffing the helmet under my belt, how tough can this be?

 

IIRC, a Dremel with a buffing wheel and toothpaste works pretty well for removing scratches from glass.

Robert

[B67FSTB]

Well done Craig !
As always you put alot of work into this !!
As for Shag's windshield , mask of the entire car with this lightweight plastic foil they use at the body and paint shop.
Tape the outer contour of the windshield and of you go.
When the windshield is installed you can push the polisher more onto the windshield.