Paint Thickness - so many numbers! What do they all mean?!

[Greg from GA]

So I got a HighLine Meter II ($149 new online at a place that seems to only sell that and another brand) and I calibrated it.  It has no problems always zeroing but the numbers definitely jump around on the calibration shims before and after the car measurements so take the data here with a 'you get what you paid for' brush.  It is for personal use I am just looking to be directionally accurate over the lives of the cars so I think I am okay.  I'll tell you two stories and a question and I look forward to your experienced opinions.

 

Story 1: Orange metallic New car - 2016 Hyundai Tuscon bought new from dealer inventory.  I do not remember how long it sat on the lot.  About a month ago, I clayed and paint corrected it with PC and Adams correcting and finishing polishes.  Did not really need to be done but wanted to start with a blank canvas so not very aggressive on the polishes.  Did go to town on the hood though due to some love marks. from either bad washes from me or dealership.  Just took readings.  Hood averages around high 4s to 5.  sides low 4s.  rear mid 3s.  Roof mid 4s.

 

Story 2: Black metallic 2013 Audi Q7 bought new and watched it ride over on the ship and come straight to me (in other words only went through dealer prep - no sitting on lot love washes).  Went through it's first paint correction about a month ago.  Prior to that I clayed it and waxed it a couple of times and went to town on the hood once due to TWICE some Orlando hard water stains (thanks WDW resort sprinklers!) with some hand applied water spot remover.  About a month ago, I clayed and paint corrected it with PC and Adams correcting and finishing polishes.  I am happy with the results and only looking to maintain it and wash it right at this point.  Also, going to drive this car into the ground.  Just took readings.  Hood averages around low 4s.  sides low 5s.  rear mid 3s.  Roof mid 4s.

 

Question: Black metallic 2015 Audi SQ5 bought new but was a dealer trade and clearly the paint was in rough shape when we got it.  Lots of swirls.  About a month ago, I clayed and paint corrected it with PC and Adams correcting and finishing polishes.  I am not happy with where it is now and I want to get more aggressive based on my recent experiences.  This car will NOT be driven into the ground - it probably will only be in my hands for another 18 months.  I have not taken readings yet because it is not in the garage today.  What do all these numbers mean in terms of setting a baseline?  I get that this is total thickness (primer, paint stages and clear coat) and has nothing to do with clear coat thickness but hey that's what I get for $149.

 

 

[shane@detailedreflections]

I have a similar gauge that I use since I haven't wrapped my head around the $2000-2500 for the higher end meter. 

 

The way I tend to utilize mine is to measure the paint in various areas of the vehicle (generally a measurement of two on each panel looking for big variations from the others that would indicate a repair/repaint).  I then take some measurements in areas that typically aren't as heavy with clear coat such as door jambs and under the hood/trunk.  Subtract the measurement of the thinner areas from the thicker areas and you'll have a very rough approximation of how thick your clear coat is with some small margin of safety for not striking through.

 

The only way to know definitively is to spend the big money for the meters that differentiate different layers. It's on my radar for someday.  Next up is a mid-rise lift for the shop to simply those wheels off jobs and to make it more comfortable of a working level.

[Sizzle Chest]

Medic hit it.  Take a bunch of readings on a panel and see what your average is.  I tend to get 'nervous' when I see readings in the low low 3mil  and mid to high 2mil range.  That being said, it doesn't mean that you don't have 'enough paint/clear' to do a correction----you can correct and then take some readings between passes to make sure you still have enough t work with. 

 

Hope this helps! 

[Greg from GA]

 I tend to get 'nervous' when I see readings in the low low 3mil  and mid to high 2mil range.  

 

 

This is the rule of thumb-type stuff I was not wanting to learn on my own. Thanks.

[Greg from GA]

 

The way I tend to utilize mine is to measure the paint in various areas of the vehicle (generally a measurement of two on each panel looking for big variations from the others that would indicate a repair/repaint).  I then take some measurements in areas that typically aren't as heavy with clear coat such as door jambs and under the hood/trunk.  Subtract the measurement of the thinner areas from the thicker areas and you'll have a very rough approximation of how thick your clear coat is with some small margin of safety for not striking through.

 

Thanks - I get the math and that's the reason I bought this meter but danged that is scary.