Polishing removes part of the clear coat. How much?

W

White95Max

New member
How much of the clear coat does polishing remove?

Specifically, I'm going to use some #81.

Are we talking a really small part of the clear coat with each polishing?

Give me a fraction.



Thanks
 
81 is mostly oils, so there is absolutely no risk at all of polishing with #81 too much. You could honestly polish your car everyday with 81 and it wouldn't remove hardly any clearcoat. Its only when you start polishing many many times with an abrasive cleaner/compund that you should be concerned with it.



BTW: It is impossible to tell exactly how much clearcoat is removed without an ETG and even that doesn't seperate BC from CC.
 
White95Max- I don't think anyone's gonna go out on a limb and give you a fraction. Just too many variables. But as Greg said, you're gonna be OK using the #81, it's practically nonabrasive. Even a stronger abrasive like #80 or #9 isn't gonna remove much and probably shouldn't be cause for concern. When you move up to #83 or something similar, THEN you have to watch that you don't overdo it.



To remove a scratch you gotta abrade away the surrounding paint until it's as low as the bottom of the scratch's "crevice". You don't want to remove more than .1-.3 microns (.0001"-.0003"!) on a clearcoated car, which sure isn't much. The consequences are not always immediately apparent, but that clearcoat is supposed to protect against UV, etc. over the whole life of the car. So even "moderate" polishing might end up being a problem if it's done often enough, long enough. If you don't get a lot of bad scratches, you'll PROBABLY be OK, just take it easy.
 
How often could you use the Menzerna twins before worrying?



What about IP every 6 months and FP monthly...too much or no problem?
 
This is a question that pops up every so often, and as said above, there are too many variables to give this a definitive answer.



Some paints are harder than others, if you're using a PC the pad changes things, your technique might be different than mine, etc, etc, etc.



While this is something people worry and wonder about, the thing is, you really shouldn't have to. Quite often new Autopia converts will come in with paint that needs more serious polishing, using moderately strong methods to do so. If you care for your car reasonably well and clean it properly though, the next time you'll need to fully detail your car you won't have to be nearly as aggressive.



So while people ask if using something moderately strong every 6 months is okay or not, it probably won't come to that. In any case, "mild" products are usually considered safer to use with more frequency (within reason), while stronger products probably shouldn't be... because they're stronger. Some of this is just common sense. :)
 
Modern paint is not designed to be buffed often.



Products like M's DACP will remove .3 mil when completely applied with a wool pad.

That is the max that should EVER be removed.



The molecules of the outermost 'skin' of the clear are the most tightly compacted, and have the most UV protection. Remove any more than that and, over time, you'll begin to see clearcoat failure as the UV protection fades and dullness sets in.



BTW, two layers of a celophane cigarette wrapper are about .3 mil thick.



Always use the least aggressive polish to get the job done.



Jim
 
jimamary- Those are some good examples :xyxthumbs



I sometimes wonder what's gonna happen with some of our vehicles....some Autopians seem to be constantly polishing out marring, trying to keep a perfect finish on daily drivers. I dunno, but in most cases, *I* would rather put up with a little marring and keep my paint nice and thick. If you want a "perfect" finish, don't let it get marred in the first place. Easier said than done in "real life", especially if the vehicle is used year-round.
 
jimamary said:


Products like M's DACP will remove .3 mil when completely applied with a wool pad.

That is the max that should EVER be removed.
Click to expand...



Jim, thanks for that information. Where did you come across that?



As far as I know (but I could be wrong, and if I am, please clue me in), there really isn't a good way to measure clearcoat thickness, unless you're willing to spend about $4k for an ultrasonic gage that can distinguish the different layers. Companies that make them are Defelsko, Panametrics, and Elektro-physik.



By the way, White95Max, you might want to check out the thread "Worrying about damaging paint". In there, BlackRegal says:



"I once saw an estimate that an agressive compound with a cutting pad on a high speed rotary would remove approximately .05 mils. So, if we extrapolate that back to TOGWT's safe removal estimate of .3 mils, you could buff a vehicle 6 times with that setup. Obviously a clear coat that is a little thicker or harder will be more forgiving than one that is a little thinner or softer."



For whatever it's worth, I once talked to a PPG rep, and she told me that the clearcoat is about 1.5 to 2.0 mils from the factory, and that you don't want that thickness to get any less than 1 mil.



Hope this helps,

Chris
 
Most of my paint info is from ValuGard's "Prep Excellence" manual and course.



The label of their 'Liquid Paint Correction Creme" actually refers to the .3mil removal.

I *perceive* that product to be comparable to the more widely known DACP...



The ETG Paint Thickness Guage runs about $450 (Check Around). Great for determining a baseline b4 buffing... Maybe next year!



ETGV Paint Thickness Gauge



Jim
 
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