Once you realize how much you don’t know; only then will you be willing to research and enhance your knowledge and understanding

Modern clear coat paint finishes are so good today that they lull people into thinking that vehicle paint has protection and shine when in reality there is not really much there, the clear coat that has a thickness of ~25.4 µ (micron). As a point of reference a sheet of copy paper is 89 µ.

There are two considerations; how much clear coat and how much ultra violet protection can be removed, they are not interchangeable. The following are the maximum allowable clear coat reductions the major USA car manufacturers will allow before the paint warranty becomes void; Chrysler- 0.5 Mil (12µ) Ford – 0.3 Mil (7.5 µ) GM – 0.5 Mil (12µ) (Source - Automotive International) A single sheet of standard printer paper is ~ 7.5 µ ( 3 Mil) thick

The clear coat provides gloss plus physical protection from the elements, including ultraviolet (UV) radiation, which is in the upper level of a cured clear coat. Most car manufacturers will only allow ~ 25% of the clear-coat thickness to be removed without voiding the paint warranty and long-term durability problems becoming an issue. That means that if you started off with 50µ of clear coat (this will vary by vehicle manufacturer) you would only be able to remove <12µ without voiding the paint warranty and possibly having a re-paint (Note: this may vary by vehicle mfg

Most light surface marring is ~1.27 µ (0 .05 Mils) a surface scratch that can catch your fingernail is ~1.01 µ (~ 0.04 Mils) Using a medium abrasive polish and a rotary polisher will remove approximately ~ 2.5 - 3µ (~ 0. 98 – 0.12 Mil) from the paint surface. To remove a scratch you need to level the paint to its lowest part, so if a scratch is 1 µ that’s the amount of paint (and UV protection) you need to remove to eliminate it. Note: 25.4 µ (micron) = 1 Mil

Using a medium abrasive polish and a rotary polisher will remove approximately 2.5 - 3µ (0. 1 Mil) from the paint surface, which is typically four passes at 1500-1800 RPM; however many variables such as polish/compound and speed / pressure used that may affect the paint removed)


There is ultra violet (UV) protection all the way through the paint, but the majority of it migrates to the top as the paint of cross-links along with the thinner solvents and particulates, the paint is also less dense (softer) below this level. The amount of migration will vary with the formulation of the paint, and which ultra violet protection chemical is used. Therefore removing clear coat ultra violet protection is not a linear process; by removing a small percentage of the clear coat paint tends to remove a larger percentage of the ultra violet (UV) inhibitors.

With a clear coat thickness of ~49µ and knowing that most of the ultra violet protection is in the top 50% (~24.5µ); therefore, limiting UV protection removal to ~25 % means that approximately < 6.125µ can e removed before the ultra violet protection is compromised. Once you remove too much clear coat you'll have no paint UV protection other than what you apply with a LSP (providing it contains ultra violet inhibitors).


Be cognizant that ultra violet protection removal is not a liner process; and the first paint renovation will remove the most UV protection, therefore the above are probably conservative estimates. Two variables need to be established; how much clear coat is available and how much clear coat can be removed without compromising the paint systems ultra violet protection, its long-term durability and / or the paint warranty


Paint Removed by Polish or Compound

Using a medium abrasive polish and a rotary polisher will remove approximately 2.5 - 3µ (0. 1 Mil) from the paint surface, which is typically four passes at 1500-1800 RPM; however many variables such as polish/compound and speed / pressure used and etc that may affect the amount of paint and ultra violet protection removed

If you have reservations about the amount of paint surface removed or the amount of paint remaining the use of a paint thickness gauge (PTG) is arbitrary. There comes a point when you must judge wither removing a scratch will compromise the clear coat and / or UV protection, if so you’ll have to ‘live’ with the imperfection

After Care

To enable a vehicle to maintain its value original paint that is in good condition is an asset. People are keeping their vehicles an average of nearly nine years. Making you client aware of how to wash and dry a paint surface while inflicting the least amount of damage will help to avoid the need to overly polish the clear coat to remove scratches and the subsequent loss of both clear coat and ultra violet paint protection. Providing this kind of value added-value services will enhance your reputation and enable you to become the source for both ethical service and high quality work. As with the successful sale of any product, educating the customer is the key.



My comments:

It seems TOWGT is stating in the article that UV and gloss are on the top part of the clear coat. You wear that away and you have nothing to maintain shine and UV protection but a LSP. Something to consider if you choose to.