Noob question, how does a paint thickness guage work?

**BigLouMaxSE** · 10-14-2005, 11:24 AM

Out of curiosity, how does a paint thickness guage work? Where can you get one and for how much? Thanks.

**BigLouMaxSE** · 10-16-2005, 04:32 PM

Would this better be suited in the Professional section of the forum? Bump to the top...

**Setec Astronomy** · 10-16-2005, 05:01 PM

A paint thickness gage is an eddy-current device, which measures....um...eddy currents in the base material and calculates the thickness of the coating (I think this is a magnetic field phenomena). Besides paints, they are used industrially for measuring the thickness of various types of plating, etc.

Some of the places you can get one are www.autoint.com, www.mscdirect.com

**Bill D** · 10-16-2005, 05:25 PM

Originally Posted by BigLouMaxSE

Would this better be suited in the Professional section of the forum? Bump to the top...

Well, I moved it to the Detailing Product forum.

I have one and enjoy using it. There are several models and at least two brands. The brand I see most often and own myself is an ETG which is made by Pro Motor Car Products I have the ETG A. I found Automotive International, linked above, to be the best source.

The paint is most popularly measured in mils and the gauge measures the total amount of paint film on the cars surfaces. I found most of the cars I measured to be in the ballpark of 4- 4.5 mils total paint film. I also noticed the ETG can measure platings such as chrome. A significant discrepancy while measuring a given area can indicate a repaint/repair of some kind, or, even that a complete factory or port repaint is present. I tried my ETG on several cars and found examples of all these. I found that pretty interesting.

While measuring paint in the case of clear coated cars, just remember it can`t measure the specific amount of clear itself. Generally, a maximum amount of about only .3 mils would be allowed before potentially damaging the entire paint film build.

I keep a chart/diagram of the ETG readings of my cars. If I`m to work on a client`s car I would be sure to ask them if the car has been buffed before and keep that in mind while taking the readings on their car.

It`s definitely a handy, fun, and in the case of professional detailing, an educational tool. :2thumbs:

**BigLouMaxSE** · 10-16-2005, 08:30 PM

Well guys, thanks very much for the links and info. And thanks for moving it too! (I really didn`t know where to put it). I figured it would measure some kind of magnetic -thing- to figure out how "far" the "attraction" is from the measuring device...I guess I wasn`t that far off (if I am interpretting your explaination correctly). This was really just a general information kind of question - something I really wanted to know for myself.

What got me thinking is: I can almost garantee that my car was never buffed, especially with a compound judging by the condition of the paint I started with. But the directions on the back of Sonus SFX-1 about wearing down paint unnecessarily had me worried a little the first time I used it. Now I want to use Optimum Compound with a polishing pad to try to get those last bits of swirls that SFX - 1 and 2 didn`t remove. I just got to thinking that maybe I wore downt he paint too much, which is why this question popped into my head.

Nonetheless, thank you for the answer.