Why do you need to measure the paint before polishing??
 

I have a question.
Why do you need to measure the paint??
Is that for you to choose which polish product you are gonna use??

Thanks.

(from my limited understanding of paint) You measure the thickness of the paint to know how aggressively you can polish the clear coat. If you use a pad thats too rough you'll eat through the clear-coat and damage the paint permanently...

Thanks for reply.
Then.. what's the clear-coat?? Is that some kind of layer formed by wax or sealant?? :rolleyes:

the clear coat is the top coat of your paint.

Uses:
- Identify repainted panels and all previous refinish work
- Buff with precision and confidence. Locate where extra work is needed
- Improve finish consistency and quality
- Cut expensive paint materials and costs
- Show customers where more paint stripping or re-clearcoating is needed
- Determine depth of acid rain damage

Then... a vehicle after great detailing would have thicker clear-coat?? or thinner??
As far as my understanding...
if the clear-coat(or paint) gets thinner whenever you polish the surface, then too frequent polishing is not really beneficial in terms of long-run maintenance, right ?

thanks.

thinner yes.

correct you can polish too much.

Generally speaking, you don't need to worry about the thickness of your paint if you're just going to polish the car. If, however, you're using a buffer and you're actually going to compound and/or wax the vehicle, you should definitely take things like that under consideration.

In some professional shops, we use paint thickness gauges to show the customers when/if they need to get a wax, because you can tell how many mils (the layers of paint and it's measurement) are left on the vehicle. A vehicle with too many mils is pretty obviously repainted, and might need more upkeep because of this; a vehicle with too few mils will need to be waxed, because the vehicle doesn't have a fresh enough coat of wax.

For residential applications, I wouldn't worry about the thickness of your paint.

So like.... it wouldn't be a matter if I polish with Menzerna PO85RD,
but it would be better to consider the thickness when I compound it with SIP..., right??

it would matter but much less, 85rd on an orbital won't do much sip wouldn't either.

I have actually never heard of taking measurements before and after wax....

I wouldn't worry about it unless your using a high-speed buffer to compound your whole vehicle. Under those circumstances, you can identify areas of your vehicle's exterior that might need extra work.

If you're just waxing your car, no, I wouldn't worry about it. If you're hand buffing a scratch off your car with rubbing compound, no, I wouldn't worry about that either.

If you're repainting your car yourself and wetsanding it, then buffing over it for that sparkling finish, then you might want to take it under consideration. ;-)

Truth be told, there are few reasons that people other than professionals would need to guage the thickness of their paint.