Why Paint Thickness Readings are Important

Evan.J

I'm addicted to Shine
Today I had privilege of working on a Porsche Turbo for a customer and all I can say its that Im glad I take readings on every car I do along with every panel I plan on polishing.

With the Porsche all washed and decontaminated I pulled out my PTG (Paint Thickness Gauge) and took my reading starting with the hood. What I found was thickness from 8.5 mils all the way up to 10.4 mils. After speaking with the owner about the hood he has stated that he heard that the hood had been repainted at some point (as were my thoughts after seeing the thickness).



I then took to the rest of the car finding your typical factory paint thickness anywhere from 3.7 mils to 5.4 mils.

While going around the car I was on the driver side door taking measurement and I was stopped dead in my tracks. I was taking reading of 1.8 mils and lower :wow:.

I could not believe what I was finding. On the door the lowest reading I took was 1.2 mils and the highest was 1.8 mils.



For those of you that don't know thats very very thin in over all paint thickness NOT just the clear coat. I then explained to the customer my findings and told him that its too risky to do any correction on that door panel at all and the chances of sticking through are very good and thats not something I am willing to do. I said for that panel I will take a finishing polish and finish pad over then panel but nothing more and he was very understanding and thankful that I explained this to him.

The point that I am trying to make is that a PTG should be in everyones bag if you doing work on cars. You also need to get the history at all possible about the car as well.

If I had not had a PTG and took reading there could have been a very good chance that I would have struck through the paint on this car causing nothing but damage and having an upset customer that might have never returned to do business again.

Don't be a guessing or blind detailer and hope that you won't strike through because if you not taking readings then you are running that risk. I would never want to see anyone run into a problem like this and do damage to a vehicle because they did not have the tools to know what they are working on. A PTG will provide you with the info that is needed to help you make better designs when working on cars.

Better to be safe than sorry :props:


For those looking for a PTG please do yourself a favor and take a look at Zach's Thread on this PTG
CM8801FN Paint Thickness Gauge - Affordable for Everyone! - Auto Geek Online Auto Detailing Forum
 
Why were you taking the measurements in mils ?

I find that measuring in microns is more sensitive to how much is being removed because 1 mil = 25.4 microns...

So by that, your picture of 9.4 mils = 238.76 microns which is a lot of paint.. Way more than the factory ever put on...

Dan F
 
Why were you taking the measurements in mils ?

I find that measuring in microns is more sensitive to how much is being removed because 1 mil = 25.4 microns...

So by that, your picture of 9.4 mils = 238.76 microns which is a lot of paint.. Way more than the factory ever put on...

Dan F

Yea the hood was repainted that why its 9.4 mils

I will take either micros or mils. Mils is a bit easier for most people. If and when I sand I usually take micros for more accuracy. :bigups
 
Is your gauge going to tell you when you take a little out of the clearcoat/paint in mils ?

Or is it not going to register a change until you remove a whole mil (25.4 microns) off ?

I would rather see it in microns, the smallest unit of measurement in this case..
Dan F
 
Is your gauge going to tell you when you take a little out of the clearcoat/paint in mils ?

Or is it not going to register a change until you remove a whole mil (25.4 microns) off ?

I would rather see it in microns, the smallest unit of measurement in this case..
Dan F

Don't worry Dan I get what you mean :bigups
 
I tend to prefer measuring in mils myself. The QNix 4500 that I have is more than capable of measuring the smallest changes in mils. It will measure mils out to the hundredth, which equates to about one quarter of a micron. I think its just a preference of whatever you cut your teeth on.
 
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