Polishing glass

[Aar1064]

Anyone here have any tips. I've got the basics down but looking for some advice on how to speed the process up. I'm currently working on the rear glass and then onto the side glass. I'm doing this simply because it's the original glass except for the drivers door and windshield. The rear is the worst and the flattest so I decided to begin with it.

I'm beginning to think I should just spring for a dated rear glass but would really like to see this through if I can. The scratches are spread out in different places so its essentially covering the entire glass. There are also rubbed lines in it where the louvers were touching and rubbing it.

Any advice would be great.

[Spikedog08]

That sounds like it needs a whole lot of polishing . . . Curious what the pro's are going to recommend . . .   

[Cuda Cody]

I remember seeing a glass how to polish video at some point?  Where is that video?    I was surprised how nice it came out.

[usraptor]

Check out Eastwood's website.  I'm pretty sure they have a glass polishing kit.

[RUNCHARGER]

There was a guy on moparts about a year ago that gave a good editorial of polishing glass. I think the short version is that it is a ton of time and perfection is not achievable. I have never tried it myself but am interested in it even to just get hard water stains off glass.

[Aar1064]

The guy on moparts was Lew and he's the one that got me started and believe it or not, it does work but man is it labor intensive. Takes a lot of time and I'm just trying to see if there is a more efficient way of doing it. The scratches aren't bad but they are there. I had a professional come out yesterday and he showed me what could be done on a small area as a test. We both concluded that it would be best if I spent the time getting it to the point to where it could be polished and then he'd step in and polish it for $200. 

He was a great guy and offered up some much needed advice on the correct sanding pads to use. 500 grit for getting the scratches out carefully followed by 1000 then 2000 and ending with polishing.

Still thinking about which way to go, new or original and If I decide to work the original, I will document and post.

[RUNCHARGER]

Let us know for sure. I have a bunch of Challenger glass I refuse to throw out. So far it has been easy enough to find a piece when I don't have one that passes the condition test but it's getting harder.

[Cuda Cody]

Yup, that's where I saw it!  It was the one on Moparts. 

[jimynick]

There was a guy on moparts about a year ago that gave a good editorial of polishing glass. I think the short version is that it is a ton of time and perfection is not achievable. I have never tried it myself but am interested in it even to just get hard water stains off glass.

We used to use metal prep- it's a dilute acid and it worked great and that was on stains that'd grown to be thick and large by being under a leak in underground parking. Just mask and mind the trim and don't let it run all over and you should see your way clear- pun intended. 

[RUNCHARGER]

Never tried it and I always have some metal prep around!

[fc7cuda]

I did some polishing on my SE rear glass before install afew years back.  It was very time consuming and you definitely want to go slow.  Too much polishing/sanding can lead to a viewing distortion at certain angles.   

[RUNCHARGER]

That was my understanding as well and you stand a chance with very light scratches but not anything more.

[nsmall]

I purchased the Eastwood glass polishing kit.  Unfortunately I was unable to get the scratches out. It did distort the glass a little bit.

Long story short, I bought new glass in Eastwood did give me a refund as I return the kit. I spent about an hour and a half on it and my main recommendation would be....make sure you don't get that glass too hot as it's easy to do and then it distorts it some.

Actually my main recommendation, buy some new glass and sell yours....

Good luck

[Aar1064]

Well I finally got this figured out. I picked up some new sanding pads that a professional recommended. They are made by Mirka and Abralon is the series name and can be bought on EBay cheaper than elsewhere. https://www.ebay.com/itm/181663917541. These pads are thick and soft which cut/polish significantly better than the ones I started out with, which cut randomly and not uniform. The secret is to get a uniform haze with the cutting/polishing discs once the deep scratches are out being careful not to get glass too hot. I used water to cool the glass down if it got to warm and I checked temp using the back of my fingers so to minimize any oils from tips of fingers. I don't have a temp gauge for glass so touch was the only way I could gauge it. I never got it so hot that I couldn't touch it. Moving the pad around not concentrating on one spot will help.

I used 3 different abrasives 500 for deep scratch removal, 1000 for hazing and removal of 500 scratches, and 2000 for final sanding/polishing then topped it off with a felt buffing pad used with cerium oxide polishing compound to bring back the shine.

500, 1000, and 2000 pads are 6 inch used on a 4 inch 5/8 arbor Velcro backing disk. I'm using a harbor freight buffer which has the RPM indicator. 2500 rpm is the sweet spot. The felt polishing pads are three inch with a padded backing disc that is attached to my drill. Padding on the discs or backing discs is key to help eliminate any gouging in the glass and the bigger sanding discs will help with a uniform haze.

500-I used this to get the deep scratches out. Before removing I marked the opposite side of glass with a black sharpe pen marking entire length of scratch. I tried to only use the outer 3/4 inch of the disc to do this (6 inch disc on a 4.5 inch backing pad) at 2500 RPM tilting the buffer at an angle. You'll want to make sure that you don't press down to hard just let the disc do the work and feather the area to minimize distortion. If there are a lot of scratches that are close together, that section will be all part of the 500 grit procedure which is okay. A 1/4 inch scratch may work out to be about a 2 inch area with 500 grit and about a 6 inch area with the 1000. This is necessary and will help with any distortions. If there are a lot of scratches like in my case, you'll have a big section worked with 1000 and it'll get a little bigger with 2000.

1000- this is used to get the 500 scratches out and begin the process of hazing. These pads last quite a while and as you can guess, will cut better while new. Most of the time this disc is used flat on glass sometimes putting a little pressure on the edge by tilting a little. You can feel and see the glass start to haze. The pad will initially just glide on glass and then you'll feel it start to grab and that's when it starts hazing. Just keep moving and checking temp. At this point your concentrating on the entire area you did with 500 so keep moving side to side and up and down.

2000- this is used to remove the 1000 hazing and begin the polishing and is always used flat on glass with gentle pressure. The longer you spend on this the less time you'll spend polishing. The haze will become lighter as you move along.

Felt polishing pad- use this liberally with the cerium oxide. Again, back and forth left to right. After it seems used up, I'll spray a little water on glass to re-activate it. Knowing how much to use is trial and error. I ordered the polishing pads and compound from glasspolishshop.com. The 3 inch backing disc is something Imhad laying around. It needs a soft foam base in order to soften the polishing.

Pads- http://www.glasspolishshop.com/consumables/polishing-pads/rayon-felt/rayon_felt_polishing_pad_75mm

Compound- http://www.glasspolishshop.com/consumables/polishing-compounds/glass-polishing
These items can be purchased elsewhere. Eastwood sells a compound so you may try it.

4.5 inch backing disc- http://www.glasspolishshop.com/consumables/backing-pads/Velcro-hook-and-loop/115mm-velcro-backing-pad-5-8

Anybody who has buffed a car will have no problem with this process. To this point I haven't tried to remove any scratches from the inside of the glass. Since the glass is curved differently, it may be tricky to keep from distorting because you may not be able to lay discs flat. It may take a while to get the feel so just be patient and you'll be fine. May be a good idea to concentrate on a small area first (start to finish)to get the feel for it.

I only did a 10x10 inch area hazing to polish testing out the new pads. This 10x10 inch area took about 45 minutes start to finish excluding deep scratch removal which had already been done. Initial scratch removal takes the least amount of time.

[Aar1064]

After 1000 grit hazing.