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So I'm an absolute novice. I've been seeing pictures of measurements of between 150-180 (microns?) does this number include the paint AND the clear coat?

When one performs correction on say, a 4-5 year old car with bad swirlmarks, how much of that gets removed? Is it just the clearcoat that gets leveled out, or do you get down into the paint itself?

Which leads to my next question.. on our M5s, how many times can paint correction be done?
 

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Using a medium abrasive polish and a rotary polisher will remove approximately 0. 1 Mil ( ) Range 0.8 – 1.1 Mil (20 – 28µ) from the paint surface (typically 4 passes at 1500-1800 RPM) but there are many variables such as the abrasive grade of the polish or compound and speed and pressure used that may affect the paint removed) These numbers should be checked with a paint thickness gauge (PTG) There comes a point when you must judge wither removing a scratch will compromise the clear coat and if so you’ll have to ‘live’ with the imperfection.


These numbers are offered as a guide only, as there are too many variables to provide any more than an approximation.


Clear Coat Thickness

A clear coat thickness is approx 2-3 Mils (50 - 75 µ) a paint thickness reading of 4 Mil < ( 100 µ (Microns) is reasonably safe for polishing. 3 – 3.5 Mil ( 80-90 µ) I wouldn't use anything stronger than > 2000 grit polish, 2.75 – 3.0 Mil (70-80µ) > 2500 grit polish and under 2.75 Mil (70 µ) use a glaze. Removing more that 0.5 mil (12µ) of clear coat will cause premature paint film failure

If you have reservations about the amount of paint surface removed or the amount of paint coating remaining the use of a paint thickness gauge (PTG) is arbitrary
 
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