Tool for polishing out etched window glass?

Hello folks. This is completely outside my area.

A friend’s store front was tagged with graffiti, and the paint etched the glass so the marks are still available. I want to polish out the etched areas. What tool should I use?

The possibilities are:

  • A drill/driver (probably not the best idea)
  • A ROS. I have a Bosch corded and a DeWalt 20v Max.
  • A sander/polisher, like that nifty M12, that I’d have to buy.

I know actual polishers would turn faster than drills, but these aren’t large areas I’m working with, and a little extra time won’t matter to me, especially since that M12 polisher is cool but not especially cheap. Also it uses a weird metric spindle, so it can’t accept common polishing disks, arbors, etc.

And the glass was just etched chemically, not physically scratched. I’m sure the etching is pretty shallow.


I was able to get a polisher pad to go on my random orbital sander and have found that to be pretty good. I also have 3 levels of pads for the drill, but they don’t work as well as you’d think and tire your wrist pretty quickly. My vote would be the ROS pad or a cheap harbor freight DA unless you think you’d want to use the M12 one enough.

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Thanks, indiana. I’ll go with the ROS.

But the next question is what kind of pads to use? There are three types: foam, sheepskin or wool felt. I can’t find anything that tells me what I should use (the abrasive would be cerium oxide.)

My only experience here is more with car windows and such so take it for what you will, but the pad I’ve used (typically with griot’s glass polish, so not sure what the abrasive is, but probably similar) is a microfiber one. Depending on how etched the glass is, you may want to start with a medium-cut foam pad and then finish with the microfiber or similar finishing pad to buff out the abrasive swirls.

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Griots makes a glass polishing pad. I’ve also used a more aggressive polishing powder that I got off Amazon.

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so I think you might have to tape off the area and start with sand paper - this is sight unseen but if you can fell with your finger tip the etch. polishing might not remove it. so like a 300 to a 600 wet and then a first polish.

I don’t know I would spend extra money on specific glass polish but would use the cheapest automotive polishes I could find. and I would use the ROS and I would use foam pads on it with the harshest ones I could find. why - glass is hard and can take it. Usually they are color coded. now I use a PC 6 inch ROS for the car so I use 6 inch pads - but they make the same system in 3 and 5 inch

anyway usually the lighter color pads (like yellow, orage) are the toothier pad - and dark colors like blue and black are the softer.

OH and cleaning the glass - I would get some bar keepers friend powder soap and use that to clean the glass first

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Oh and to prevent stuff sticking you could treat the windows with either quality polymer finish coat like used on car paint or you cold treat the windows with PPG Aquapell.

might even prevent paint from sticking in the future. I use this on the windshields of my cars.

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Thanks, Napalm and LarryB. That helps.

I’m more familiar with wood than glass, but it seems like as far as surface finishing goes, it isn’t much different (start with coarser, move up to finer, etc.)

I didn’t know ab9uot PPG Aquapell. Thanks, Napalm!


I asked a buddy who has a lot of auto paint experience and his reply was that a random orbit will be the slowest or least aggressive tool, a normal rotary polisher/sander/grinder would be in the middle, and at the fastest / most aggressive would be a dual action polisher. The latter is sort of like a random orbit except both of the motions are powered. For auto paint it’s possible to burn the finish so there is a learning curve, newbies should use random orbit, it takes skill to use the dual-action polisher without causing damage. But you’re polishing glass, which you cannot “burn”, so his recommendation was to go as aggressive as you can. If you don’t have access to a dual-action polisher a standard rotary tool will be faster than the RO.

And this just “clicked”: what on earth are people using for graffiti these days? There are very few chemicals which can etch glass and they are all nasty nasty nasty.

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unless you alredy own a rotary tool - or you wanted to put a 5 inch pad on your angle grinder

use the ROS and take a little longer.

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went to fast. use the tool you have as opposed to significant additional costs.

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Thanks for asking your friend, Mecha! I appreciate it.

I’m thinking of starting with a dremel tool with a felt bob, because although the tag is big, the actual area that’s etched is pretty small. Then move to the ROS to even it out.

Yeah, it’s not nice. Apparently they use an etching cream or paste that contains hydrofluoric acid. You can get it at craft stores. Supposedly it isn’t dangerous if you wear gloves and goggles. They apply it with a plastic foam-tip bottle. I guess they do it because the marks are harder to remove than spray paint. But a lot of taggers don’t like it, because there’s little art to it, and it’s “straight-up vandalism,” as one guy put it.

I don’t know if aquapel would stop that but it might. it’s a glass sealent but really meant as a hydrophobic coating.

meanwhile a solild car polish might work - something like meguiars mirror glaze or that new 2.0 stuff they make. (cream to be put on with buffer). IT’s a poliymer acrylic setup - that might prevent other issues.

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I’m familiar with that product, just never knew that the graffiti crowd got wind of it. HF is nasty, in that form it’s rather dilute but it’s still not something I’d want to handle without serious PPE. I guess I shouldn’t be surprised though, there is apparently a large market for specialist graffiti supplies that are meant to make it difficult to remove. I’ve seen special paints advertised to cover up other tags, or to make it more difficult for your tag to be covered by others. Markers which are meant to bleed through attempts to paint over them, and so on, so it seems that taggers are into making their mark last.

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I’m a little nervous about using car products on clear window glass. Wouldn’t they leave behind something that might make the glass hazy?

I played with HF in chemistry classes, and actually it was less dangerous than some other things we used (like phosphoric acid, or liquid bromine). Outdoors, with goggles and gloves it should be okay.

I could understand paint designed to cover up other tags, because that would have legitimate uses, but I can’t conceive of why markers designed to bleed through would ever be a good thing.

That’s basically what I was implying. If an angle grinder or similar, or you happen to know someone with a dual action polisher then use that over the random orbit but there’s certainly no reason to go buy a special tool just for what sounds like a one-off fairly small job.

Car products could certainly work assuming it’s an abrasive polish and not just a “wax”, but I’d think the cerium oxide paste would be better. I know that’s professional glass shops use, while it’s possible the auto polish’s abrasive is hard enough to cut clearcoat but not hard enough to cut glass, whereas that question doesn’t exist for the cerium oxide paste–we know it works.
I doubt they’d leave behind any sort of hazy film though, that’s the last thing someone wants on their fancy custom paintjob. And even if it did? It doesn’t really matter, it’s glass, and thus is impervious to pretty much anything short of HF. Grab a rag with some acetone or denatured alcohol or similar and whatever residue is there will come right off with zero risk to the glass.

Phosphoric acid more dangerous than HF? I think you may have that backwards. The risk isn’t so much the corrosive nature of the acids, it is the toxicity. There’s a whole rather gruesome article about the effects of a hydrofluoric acid burn, even a small exposure to a finger can cause death by cardiac arrest, meanwhile phosphoric acid is benign enough that it’s found in quite large amounts in soft drinks. HF has a “4” for the health risk category of the NFPA diamond, Phosphoric Acid is a 3.

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Re car products, that makes more sense than what I was saying, Mecha!

And you are right re phosporic acid vs HF. I think I was remembering, from 40 years ago, the interesting fact that phosphoric acid can continue to give up protons one after the other, so it’s harder to neutralize per mole. But you’re right, it isn’t as dangerous as HF. I didn’t do well in orgo!

So this may or may not be helpful, but I asked my wife since she’s done some hobby etching with that same kind of paste you mentioned. I know she’s removed/redone some screwups before…apparently it depends on how long it’s left on, but baking soda toothpaste, vinegar, and acetone can be used (separately, not mixed) as options to remove. The latter two are a soak, so not sure how you’d accomplish on plate glass (maybe some type of saturated sponge taped to the glass?), but the first one might be a cheap and easy thing to try.

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Thanks, indianajonesy.

Baking soda toothpaste might work, since it’s a mild abrasive. I don’t see how vinegar and acetone would work though. The glass itself is etched. There’s no paint or other coating on it.

But I already have cerium oxide, so that’s what I’ll use. I just need to get the right pad.