# using v. fine steel wool on windshield ??? **URL:** \ **Category:** Factual Questions\ **Created:** [December 16, 2014, 12:13am UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332 "2014-12-16T00:13:38Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![kopek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kopek/32/337_2.png) [@kopek](https://boards.straightdope.com/u/kopek)\ **Post date:** [December 16, 2014, 5:03am UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/21 "2014-12-16T05:03:34Z")
> [@Ranger\_Jeff](#): > > The folks that install new windshields use foamy stuff and brown paper towels torn from a roll. That’s good enough for me, they’re the professionals. If there was a real persistent dead bug corpse, I’d try a scrubby sponge, the kind you use on non-stick treated pots and pans. For dead bugs I suggest an actual “bug release” such as the one offered by Wizard brand polishes. The stuff is more than worth the cost after you’ve driven through a couple hatches at high speed. And its even safe on the plastic stuff us bikers have. ---
**Author:** ![FluffyBob](https://avatars.discourse-cdn.com/v4/letter/f/ecb155/32.png) [@FluffyBob](https://boards.straightdope.com/u/FluffyBob)\ **Post date:** [December 16, 2014, 5:32am UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/22 "2014-12-16T05:32:37Z")
I am really amazed by the number of people in this thread that were under the impression you could scratch glass with steel. A standard tool in the window washing trade is razor blades. There are [huge blades](http://www.cleaningshop.com.au/contents/en-us/d1153.html) marketed simply for scraping windows. How else do you think paint is removed from a window? If a particle of sand (or…glass) is caught in the steel, that can scratch the glass; hence the use of lubricants which help lift debris away from the surface. You have to be careful when using anything on glass that it is not contaminated with any kind of grit. Special coatings can be scraped off by steel but I think those are not usually applied to the exposed surface. To cut glass you need carbide at the very least, and if you do not want to spend all afternoon you use diamond blades or bits. Glass is HARD. ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [December 16, 2014, 5:50am UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/23 "2014-12-16T05:50:27Z")
[Related thread](http://boards.straightdope.com/sdmb/showthread.php?t=611443) from a few years ago, complete with shock and horror at the idea of using steel wool on glass from those who’ve never done it, and knowing reassurance from those who have. ---
**Author:** ![The\_Joker\_and\_the\_Thief](https://avatars.discourse-cdn.com/v4/letter/t/e79b87/32.png) [@The\_Joker\_and\_the\_Thief](https://boards.straightdope.com/u/The_Joker_and_the_Thief)\ **Post date:** [December 16, 2014, 5:54am UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/24 "2014-12-16T05:54:23Z")
> [@SuperAbe](#): > > The inverse, actually - glass is commonly harder than steel. While the comparison between various hardness scales are a little funky, the hardest tool steels top out at [Rockwell numbers around 65](http://en.wikipedia.org/wiki/Rockwell_scale) (though there are some that hit 70-72\*) - [an Rc 72 value is (roughly) equivalent to a Mohs hardness of 4.5](http://www.cidraprecisionservices.com/mohs-conversion.html). The softest glass glass compounds are [Mohs](http://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness) 4.5 - with more typical glass compounds at Mohs 5.5 and the [hardest commercially-available glass coming in around 6.5.](http://www.tedpella.com/company_html/hardness.htm) > > - Yes, there are a small handful of weird alloys that have been reported to have (converted) Mohs values above 6.5 - that I know of these are so brittle as to have little value commercially (at least in widespread use). Huh, everything I’ve ever heard is that steel is harder. Your own last link lists steel’s hardness as 5-8.5, not the 4.5-6.5 you state in your post. And knife steels, generally, have nickel or chromium mixed in to prevent corrosion (which reduces both hardness and toughness), while I can’t imagine any corrosion resistance in steel wool. [Here](http://www.oakton.edu/user/4/billtong/eas100lab/hardness.htm) [are](http://www.rockroost.com/Mohs-hardness-scale-tips.shtml) [three](http://anythingbutipod.com/2009/04/glass-screen-durability-test-a-lesson-on-the-mohs-hardness-scale/) more links–in addition to the one you gave me–that suggest steel is harder. ---
**Author:** ![The\_Joker\_and\_the\_Thief](https://avatars.discourse-cdn.com/v4/letter/t/e79b87/32.png) [@The\_Joker\_and\_the\_Thief](https://boards.straightdope.com/u/The_Joker_and_the_Thief)\ **Post date:** [December 16, 2014, 6:02am UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/25 "2014-12-16T06:02:09Z")
> [@FluffyBob](#): > > I am really amazed by the number of people in this thread that were under the impression you could scratch glass with steel. A standard tool in the window washing trade is razor blades. There are [huge blades](http://www.cleaningshop.com.au/contents/en-us/d1153.html) marketed simply for scraping windows. How else do you think paint is removed from a window? > > If a particle of sand (or…glass) is caught in the steel, that can scratch the glass; hence the use of lubricants which help lift debris away from the surface. You have to be careful when using anything on glass that it is not contaminated with any kind of grit. Special coatings can be scraped off by steel but I think those are not usually applied to the exposed surface. > > To cut glass you need carbide at the very least, and if you do not want to spend all afternoon you use diamond blades or bits. Glass is HARD. I’ve used razor blades on glass before, but it never bothered me because 1)they weren’t my windows I was working on and 2) the razor blade and the window are both are very smooth, so there’s almost no chance for a scrape. If I can drag a razor over my skin (mohs hardness \<1?) without cutting myself I can certainly do it over a tough piece of glass. I’m also not sure what glass you’ve been working with, but I’ve cut normal windowpane glass by scoring it with a steel glass cutter and breaking it by hand. (of course, I realized just as I passed the point of no return that I was working with tempered glass…) ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [December 16, 2014, 6:20am UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/26 "2014-12-16T06:20:21Z")
I have indeed scratched glass with steel. I was using a screw driver to scrape off a sticker… well the razor blade is so thin… it won’t scratch glass… the sharp edge would fold over or otherwise become blunt first … so too the fine steel wool won’t put any force on… ---
**Author:** ![SanDiegoTim](https://avatars.discourse-cdn.com/v4/letter/s/85e7bf/32.png) [@SanDiegoTim](https://boards.straightdope.com/u/SanDiegoTim)\ **Post date:** [December 16, 2014, 1:31pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/27 "2014-12-16T13:31:59Z")
Before I’d use anything abrasive on a windshield I’d use a clay bar. ---
**Author:** ![Omar\_Little](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/omar_little/32/269_2.png) [@Omar\_Little](https://boards.straightdope.com/u/Omar_Little)\ **Post date:** [December 16, 2014, 2:18pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/28 "2014-12-16T14:18:48Z")
> [@Iamnotivan](#): > > A friend said some gas station attendant showed her > [@Rick](#): > > Back in the day when you bought gas the attendant cleaned the windows. That stopped about 40 years ago. Not if you live in New Jersey or Oregon, where self service stations are outlawed. ---
**Author:** ![riff\_raff](https://avatars.discourse-cdn.com/v4/letter/r/97f17d/32.png) [@riff\_raff](https://boards.straightdope.com/u/riff_raff)\ **Post date:** [December 16, 2014, 3:22pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/29 "2014-12-16T15:22:48Z")
I resurrect ancient VW microbuses for fun. I have used 0000 steel wool on every surface imaginable on these things. I have used steel wool on glass that has not been cleaned for 50 years and there is really nothing else I have found that will clean old glass as well as 0000 steel wool. I have seen no evidence of even micro scratches on the glass post steel wool. ---
**Author:** ![FluffyBob](https://avatars.discourse-cdn.com/v4/letter/f/ecb155/32.png) [@FluffyBob](https://boards.straightdope.com/u/FluffyBob)\ **Post date:** [December 16, 2014, 3:43pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/30 "2014-12-16T15:43:09Z")
> [@The\_Joker\_and\_the\_Thief](#): > > … I’m also not sure what glass you’ve been working with, but I’ve cut normal windowpane glass by scoring it with a steel glass cutter and breaking it by hand. (of course, I realized just as I passed the point of no return that I was working with tempered glass…) No you did not. You scored it with a [carbide](http://www.oaklanddiamondtools.com/carbide-glass-cutting-wheel.php) blade and then it broke along that weakness when you applied a force. You could take a High Speed Steel (a very hard tool steel) drill bit and a power drill and probably barely mark the glass. If you scratch glass with regular steel it is because harder particulates like a bit of sand or glass are being dragged by the steel. ---
**Author:** ![Fubaya](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@Fubaya](https://boards.straightdope.com/u/Fubaya)\ **Post date:** [December 16, 2014, 4:41pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/31 "2014-12-16T16:41:48Z")
As I said a few years ago in that other thread, body shops, detail shops and car dealers routinely use steel wool on windshields. When I worked at a body shop, it was standard procedure for the detail guys to use steel wool on every car to ensure there was no overspray on the glass. The place I worked was high volume, so I probably saw 10,000 cars go through and steel wool never hurt any of them. A good half of the business was high end and exotic cars too, the kind you might expect to have fancy or different parts, but no, it’s just glass and steel wool didn’t hurt any of them. The one thing they were wary of were cars with a lot of aluminum, especially structural. Some had to be repaired separately from the rest of the vehicles using tools that never touched steel. I don’t know all the details but corrosion is the worry, and they didn’t use steel wool on those because the fine steel bits might get washed down into where the aluminum parts were and cause corrosion. That was something they came up with on their own, maybe they were being overly cautious. Otherwise, steel wool was used on just about every car you could name. ---
**Author:** ![bordelond](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bordelond/32/150_2.png) [@bordelond](https://boards.straightdope.com/u/bordelond)\ **Post date:** [December 16, 2014, 5:20pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/32 "2014-12-16T17:20:43Z")
Tangent: Does isopropyl alcohol or acetone (in the form of nail polish remover) help with removing grime from old windshields? Say, soaking a wadded-up coarse shop rag with one or the other chemical? ---
**Author:** ![Scumpup](https://avatars.discourse-cdn.com/v4/letter/s/ce73a5/32.png) [@Scumpup](https://boards.straightdope.com/u/Scumpup)\ **Post date:** [December 16, 2014, 5:30pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/33 "2014-12-16T17:30:21Z")
I’ve successfully cleaned some seriously soap scum and mineral encrusted bathroom tiles with fine steel wool and acetone. I imagine it would work just as well at getting the greasy layer of road film off your windshield. You’d want to be extra-special careful to avoid slopping any on your car’s paint, though. It would remove any car wax you have on for sure, and probably wouldn’t do the clearcoat and paint any good. ---
**Author:** ![aruvqan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aruvqan/32/2891_2.png) [@aruvqan](https://boards.straightdope.com/u/aruvqan)\ **Post date:** [December 16, 2014, 5:47pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/34 "2014-12-16T17:47:22Z")
Huh, interesting. We have a parts hulk in the pasture, I may have mrAru wander out with some supplies and have a go at various parts. We have pernicious bugs and sap dripping trees that love bombing the cars. ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [December 16, 2014, 6:32pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/35 "2014-12-16T18:32:08Z")
> [@FluffyBob](#): > > I am really amazed by the number of people in this thread that were under the impression you could scratch glass with steel. A standard tool in the window washing trade is razor blades. There are [huge blades](http://www.cleaningshop.com.au/contents/en-us/d1153.html) marketed simply for scraping windows. How else do you think paint is removed from a window? Isn’t this like saying that human skin must be harder than steel because we all shave every day without cutting ourselves? What you can do with a razor blade held at the appropriate angle tells you nothing about the overall hardness of the surfaces. ---
**Author:** ![Scumpup](https://avatars.discourse-cdn.com/v4/letter/s/ce73a5/32.png) [@Scumpup](https://boards.straightdope.com/u/Scumpup)\ **Post date:** [December 16, 2014, 6:38pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/36 "2014-12-16T18:38:43Z")
You can polish a steel fountain pen nib by drawing circles with it on a flat piece of glass. The steel (slowly) wears away, not the glass. The glass, itself, shows no scratches or other wear. If the steel wasn’t being worn away, no polishing would take place. A flat piece of glass can also be used as an ultra-ultra-fine sharpening stone as a last step before stropping a blade. Again, polishing requires that the glass wears away the steel. ---
**Author:** ![TSBG](https://avatars.discourse-cdn.com/v4/letter/t/77aa72/32.png) [@TSBG](https://boards.straightdope.com/u/TSBG)\ **Post date:** [December 16, 2014, 6:43pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/37 "2014-12-16T18:43:01Z")
You can scratch glass with a razorblade. Once many years ago I was cleaning dried wax droplets off a glass-topped coffee table using the utility single-edge blades you get at a hardware store. I made several distinct scratches before I realized what was happening and switched to a plastic scraper. ---
**Author:** ![Doug\_K](https://avatars.discourse-cdn.com/v4/letter/d/b5ac83/32.png) [@Doug\_K](https://boards.straightdope.com/u/Doug_K)\ **Post date:** [December 16, 2014, 8:14pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/38 "2014-12-16T20:14:26Z")
> [@TSBG](#): > > You can scratch glass with a razorblade. Once many years ago I was cleaning dried wax droplets off a glass-topped coffee table using the utility single-edge blades you get at a hardware store. I made several distinct scratches before I realized what was happening and switched to a plastic scraper. You can scratch glass with _fingernails_. It just doesn’t happen immediately. When I was an optician I saw hundreds of glass lenses with diagonal scratches on the backside. They were the result of the wearer frequently rubbing their eyes with a finger under their glasses over a long period of time. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 16, 2014, 8:41pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/39 "2014-12-16T20:41:54Z")
Water can wear away granite, so it isn’t just a case of what’s-harder-than-what. That said, abrasives and polishing compounds are all part of the same spectrum, really. Very fine abrasives will make things more shiny and smooth, not less. ---
**Author:** ![mmmiiikkkeee](https://avatars.discourse-cdn.com/v4/letter/m/edb3f5/32.png) [@mmmiiikkkeee](https://boards.straightdope.com/u/mmmiiikkkeee)\ **Post date:** [December 17, 2014, 4:21pm UTC](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332/40 "2014-12-17T16:21:58Z")
> [@](#): > > You can scratch glass with _fingernails_. It just doesn’t happen immediately. When I was an optician I saw hundreds of glass lenses with diagonal scratches on the backside. They were the result of the wearer frequently rubbing their eyes with a finger under their glasses over a long period of time. I believe most lenses for the past few decades have been made of some sort of plastic which would almost certainly be nowhere near as hard as glass. Also keep in mind that little bits of dust and grit are constantly getting on our fingers and other body parts. I occasionally find a grain of sand in my hair or under a fingernail… the really fine grains you likely can’t even detect buit they are there. These tiny bits of dust are the actual abrasives, not our skin cells. > [@](#): > > Water can wear away granite, so it isn’t just a case of what’s-harder-than-what. That said, abrasives and polishing compounds are all part of the same spectrum, really. Very fine abrasives will make things more shiny and smooth, not less. It’s not the water molecules that wear away granite, it’s the little bits of abrasive material the water rubs against the rock that erode it. Pure liquid water with no impurities isn’t going to physically abraid much of anything. Most of the channel carving done by water is by way of mobilizing loose sediments and flushing them downstream rather than by mechanically scoring solid bed material. The actual abrasion of the bedrock or gravels/sand happens as the particles rub against each other while tumbling downstream; that’s how river gravels get rounded. Water acts like the air in a sand blaster; without the abrasive sand nothing will get polished. [Previous page](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332.md?page=1) [Next page](https://boards.straightdope.com/t/using-v-fine-steel-wool-on-windshield/707332.md?page=3)