I see machine polishing (not compounding) is done regularly by some members here. How many times can machine polishing be done over the life of the car before the clear coat becomes too thin ?

 

Not an answerable question ... to many variables. I polish mine out once a year and spot polish as needed but I don't abuse mine so very light polishing does it.

I have reg. customers that I have told I won't polish them out any more because they abuse them too much and things are getting thin.

Mind you they just buy a new car or lease one every 3 years.

 

Removing more that 0.5 Mil (12.5µ Microns) of clear coat will cause premature paint film failure as a point of reference a sheet of copy paper is 3.5Mil (89µ Microns) removing more that 0.3 Mil (7. 5µ Microns) of clear coat will cause premature paint film failure a surface scratch that will `catch' your fingernail is approximately 0.04 Mil (1.0 µ Microns) deep will usually require wet sanding and refinishing.

Paint Removed by Polishing
Using a medium abrasive polish and a rotary polisher will remove approximately 0. 1 Mil (3µ Microns) from the paint surface (typically 4 passes at 1500-1800 RPM) but there are many variables such as polish/compound and speed / pressure used that may affect the paint removed) 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. 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

 

if your using a pc/udm and like me only need a white pad for the routine polishing that right now i do about 2 times a year, i would think you can get away with doing that for a really long time....i have a few minor clear coat scratches that wont come out with the white pad, and mild cleaner/polish i use, so that tells me that using the white pad and udm with mild polish doesnt remove anything or a very minute amount of clear...

now with a rotary, i suspect you are removing clear pretty quick, so i wouldnt use a rotary as a maintainer....

 

I've often wondered this as well. Just how "thick" is a clear coat layer on a typical car, and how much, in absolute terms, does an A+ detail job with paint correction usually remove?

 

Paint Thickness
Most modern vehicle paint film systems comprise a Primer coat of 2Mils, a Colour coat of 1-2Mils, and Clear coat 2-3Mils. Ultra violet protection (UV) migrates to the top of the clear coat to protect the paint system from the effects of (UV) radiation (photo synthesis (colour fading) oxidation) The clear coat provides protection from environmental damage (industrial fallout, bird excrement, road dirt and debris and airborne bug debris)

Removing more that 0.4 mil of clear coat will cause premature paint film failure as a point of reference a sheet of copy paper is 3.5Mil (0.0035”)

 

Good info. here. Thanks.