Is there enough clear coat left to compound/polish for ceramic coat? Paint thickness check.

I have a 2009 DCSB SR5 in Graphite Grey Metallic with 300K miles. Living in SoCal with a 100% outdoor kept truck, the paint takes a beating. I try to protect it, keep it washed, two bucket method, using quality synthetic wax at least once a month, but the paint is showing sun damage.

The roof is completely oxidized. I put a roof rack to hide the sun damage last year. I might spray paint it flat black. The high points of the fender and doors at the base of the windows are starting to oxidize from sun damage as well.

I used a paint thickness gauge to check the truck after today's wash. Where the paint still looks good ranged between 3.25 mil - 3.75 mil, while where there is oxidation, thickness is around 2.4 mil - 2.8 mil.

What is factory thickness for a 2nd gen? Is it 2 mils of clear, 3 mils of base for a total of 5 mils?

I would like to clay bar and compound the truck so I can ceramic coat and save what is remaining of the clear coat, but I am afraid I might burn through what is left of the clear coat.

 

Take readings in the door jamb, usually it's the thinnest paint on a vehicle and it should be least compromised to UV damage since it's generally covered. Might even find painted without clear under the hood but that may be wildly inaccurate.

I think polishing takes away 1 micron where as compounding can take as much as 10. (mils to micron converter). 10 microns is about .4 mils so you might be asking for trouble polishing sections with readings under 3 mils. Hard to say what your truck had new but 5-6 mils seems about right for a Japanese car with that age. Newer paint is even worse new Mazdas have about the thickness of your good sections when brand new.

Might want to give a paint cleanser a try or a super fine polish at the maximum so at least the coating has a clean surface to bond to. Compounding will just chew up what UV protection the clear has left. So you don't have to burn through to still be compromising the paint.