Using paint depth gauge

[Kial91]

I purchased a cheap paint depth gauge from Ebay to test out but I'm not very familiar with using them. I'm getting readings of 1.31 mm and 51.6 mil.
Can anyone explain to me what this means? I was expecting it to say something like 5.0- 6.0 not 51
This was taken from the hood of my 2016 Triton gls

Cheers

[Rsurfer]

I purchased a cheap paint depth gauge from Ebay to test out but I'm not very familiar with using them. I'm getting readings of 1.31 mm and 51.6 mil.
Can anyone explain to me what this means? I was expecting it to say something like 5.0- 6.0 not 51
This was taken from the hood of my 2016 Triton gls

Cheers

Did you calibrate the gauge?

[Kial91]

Yeah I did. It came with a little silver coin thing

[Rsurfer]

Yeah I did. It came with a little silver coin thing

Try taking a reading on another car. l.31 mm, did you mean microns?

[Kial91]

On the gauge it says either mm/mil

[Calendyr]

On mil is roughly 25 microns. 24.something to be vaguelly precise :)

A typical factory paint job will be in the 100 to 150 micron range (4 to 6 mils)

If you come upon something bellow 100 microns, be very careful about what you do to that paint, this is awefully thin.

So the meter is giving you the total thickness of the paint. That includes the primer coat, color coat and clear coat. The only aspect of this you have any interest in is the clearcoat. It's impossible to know what % of the total that is but there are tricks you can use to get an idea.

First, the clearcoat it usually about half of the total thickness, but that is not always the case.

Second, you can take a reading in the door jambs and compare it to the reading on other panels. Usually, it will be thinner in the door jambs because they put less clear coat there. So the difference is actually extra clear on the other panels.

Last, you don't want to reduce the clear too much. I try to never remove more than 10 microns no matter how thick the paint is. And you don't want to remove more than about 20% of the clear coat. So let's say the paint reading is
125 microns (5 mils), 20% of that would be 25 microns, that would be the absolute maxiumum you should remove but to be safe you should try not to remove more than 10 microns.

This is useful when wet sanding or doing heavy compounding. For polishing, you are removing so little paint it's not even worth mesuring it.

[Mike Phillips]

I purchased a cheap paint depth gauge from Ebay to test out but I'm not very familiar with using them.




Why are you "primarily" using it?

Do you detail cars professionally? (that means detail cars for money)

OR

Just detailing your own cars?


:)

[Kial91]

So wouldn't 51 mil be a hell of a lot of paint etc if 1 mil is 25 microns? Finding this a little confusing haha!

[Kial91]

I have recently started my own detailing business so thought I would get one as I do paint corrections with a DA and would like to start learning to wetsand etc. And also so I can check the paint before working on it.

[Mike Phillips]

So wouldn't 51 mil be a hell of a lot of paint etc if 1 mil is 25 microns?

Finding this a little confusing haha!




No, that would be approximately 2 mils of paint.

Click the link below and look at the pictures....


Clearcoats are thin by Mike Phillips (http://www.autogeekonline.net/forum/ask-expert-featuring-mike-phillips/87410-clearcoats-thin-mike-phillips.html)


:)

[Kial91]

Thanks for the link.
I'm going to say this paint gauge was a waste of money as this is a new car, never had a paint correction and always has a wax or sealent applied.
I tested my partners car and it said the same or near enough.

Is there a decent paint gauge which doesnt have a massive price tag on it that you can recommend?

[Mike Phillips]

I have recently started my own detailing business so thought I would get one as I do paint corrections with a DA and

would like to start learning to wetsand etc.

And also so I can check the paint before working on it.



All good stuff but PLEASE - before you ever wetsand any car, start by reading this article.

Wetsanding - Fresh Paint vs Factory Paint (http://www.autogeekonline.net/forum/wet-sanding-cutting-buffing/21471-wetsanding-fresh-paint-vs-factory-paint.html)







Thanks for the link.

I'm going to say this paint gauge was a waste of money as this is a new car, never had a paint correction and always has a wax or sealent applied.
I tested my partners car and it said the same or near enough.



I typed about this just a day ago or so...

https://www.autogeekonline.net/forum/auto-detailing-101-a/120257-messuring-clearcoat-single-paint-gauge-2.html#post1589507



First - I don't know anyone that has the very expensive gauge that reads all layers.
Even if you did have one, to properly use it would take HOURS.
While someone is using it I could have the car buffed out and be paid --> $$$ and then moving on in life.

If you read enough threads on this forum about PTGs - when I comment I say the same thing, in fact I should write an article on the topic. I use a PTG for 2 things,



As a BIG PICTURE indicator

Marketing




An accurate PTG will let you know relative paint thickness and this will let you know whether to compound or avoid compounding and stick with light duty products.
For marketing, you can use this tool to show a potential customer that you really know your craft. My guess is after you sticker shock the potential customer and they go somewhere else, the next guy will NOT have a PTG and this potential customer will at least see the difference between someone that knows his craft and has the tools to prove it and a detailer that may know is craft but does not have the tools to prove it.

:)






Is there a decent paint gauge which doesnt have a massive price tag on it that you can recommend?




Not at this time, kind of a "technology thing", the better the technology the more it costs. All the cheap gauges to my knowledge are copies of the good stuff, but just not as good.


:)

[Kial91]

Oh dont worry I'm not going to be wetsanding just yet, I've only been watching some YouTube videos etc but before I do any, I'll be practicing on some old hoods, doors etc.
Thanks for the advice

[UncleDavy]

It sounds like it should be the over way around. Clear coats are generally 2 mils thick max or 50 microns. The total thickness of a new car is generally 120 microns and that includes all three layers. It sounds like your calibration and/or your units are off.

[Farmallluvr]

I can't ever remember using one after my high school autobody class but there times I've wished I'd had one to save some grief.
like when no one informs that you are the 3 rd or 4th guy to attempt to wetsand and buff a scratch and then guess what happens.