Measuring clear coat ? is it possible ?

T

thedoc46

Member
Joined
Apr 3, 2015
Messages
51
Reaction score
0
I know that there are devices that'll measure paint. But what about the thickness of clear coat ? Owned my two black VW's since new. Both 2018's. Anyway I did an initial paint correction after delivery from the dealer. 18 months or so ago, and ever since then i've been cleaning on a weekly basis and waxing and sealing every few weeks.. (hey i enjoy it) i can probably start to see some 'very' fine hairline scratches in the direct sun. I have all the MF cutting pads / compounds / polishes and an MT300. However i plan on keeping these cars for a few yrs. I'll probably pass at least one of these cars to my kids, since they're coming to that age ! Given these are very fine scratches we're talking about and are only visible in direct sunlight.

I live in the blistering heat and sunshine, aka the Sunshine state !!! so would like to weigh up if its worth it to remove that ever so slight amount of clear coat to satisfy my own OCD !

I'd really like to do a test on a panel and measure what gets removed. if that's even possible.

I know its sort of an impossible question to truly answer given the variants, but how many paint corrections can a pro detailer do on a customer he knows, and knows he's the only person who's worked the paint and assume he's still in the safe zone.
 
Minimal clear coat is used in the door jambs. You could take the highest reading there and compare it to what's on the outside of the vehicle. I say highest to be conservative. Base coat is probably a little thinner there as well, I would guess anyway.
 
You may have a ton of clear, the issue is the top.5 mils which is where the UV protection is. There is a PTG that claims to be able to measure each layer, but after talking with people who have used it, they say it’s not accurate.
 
High end paint gauges can measure each layer. I have no idea how they do that but they can tell you how much clear you have. From what I understand, you can expect to pay thousands of dollars for those. I personnaly see very few scenarios where it would make sense to buy one. Only situation I can see would be a detailer working on priceless cars on a regular basis.
 
Calendyr said:
High end paint gauges can measure each layer. I have no idea how they do that but they can tell you how much clear you have. From what I understand, you can expect to pay thousands of dollars for those. I personnaly see very few scenarios where it would make sense to buy one. Only situation I can see would be a detailer working on priceless cars on a regular basis.
Click to expand...

There was one member who used to be on here, Docshine and he had a meter via software on his laptop that could do microscopic analysis. It was thousands of dollars.

As mentioned above, common sense and rule of thumb have to apply. Taking a measurement of the door jamb is a base line of “how low it can go”

Next, do a VIF on your own car and take three measurements of each panel. File that away as reference.

I wouldn’t go crazy looking at every little scratch on the vehicle…. If you have not done a ceramic coating, the car is a great candidate for AIO. Annually go over the car with an all in one, and your favorite sealant. keep it simple... :)

Now not having a PTG is IMO a risky gamble for those doing paint correction, especially on customer cars.

As me I mentioned above, you can use the PTG to analyze the paint and get measurements to see what your working with in conjunction to the door jams.

New factory paint should be 4-6 mils and if I don’t see much of a variance between the door jam and the actual paint readings, I know I have to go exceptionally light and conservative. Again, a polish /AIO candidate.


Sent from my iPhone using Tapatalk
 
Didn’t know some of this, glad I read. Learned something new today


Sent from my iPhone using Tapatalk
 
Mike lambert said:
You may have a ton of clear, the issue is the top.5 mils which is where the UV protection is. There is a PTG that claims to be able to measure each layer, but after talking with people who have used it, they say it’s not accurate.
Click to expand...

Not sure where you heard this but it’s incorrect.

UV inhibitors are distributed evenly through the entire clear coat.

The further you cut through the clear, the less inherent UV inhibition it has until you reach UV absorption and the base begins to degrade.
 
The underside of the hood I think mostly is just primer and base coat and not any clearcoat a bit from the edge where it's useally blended with clearcoat. Or it's a very thin clearcoat on it. So much is to compare the readings from underside of the hood or door jambs. To the measure on the paint and remember to take on every panel as even a new car this can be a difference from panel to panel.

There are very expensive ones that can read the layers of different paints thickness. But also some vehicals modells have panels made of different material. As steel and aluminum and plastic and carbon fiber. So if you want to have a paint thickness gauge that measures on different material it's also often more costly.
 
OP here. Thanks for the replies. Good to know all this. I will get a PTG and measure under the hood and door jambs then compare with each panel on the car.

OK next question. What is a good reliable PTG that doesn't cost an arm and a leg. I'm just a weekend warrior. So thousands is out of the question. But a few hundred bucks, for a lifetime of measuring paint over my current and all future vehicles, I'm very open towards.
 
thedoc46 said:
OP here. Thanks for the replies. Good to know all this. I will get a PTG and measure under the hood and door jambs then compare with each panel on the car.

OK next question. What is a good reliable PTG that doesn't cost an arm and a leg. I'm just a weekend warrior. So thousands is out of the question. But a few hundred bucks, for a lifetime of measuring paint over my current and all future vehicles, I'm very open towards.
Click to expand...

Don’t bother about the underside of the hood, most vehicles have no clear at all.
 
thedoc46 said:
OP here. Thanks for the replies. Good to know all this. I will get a PTG and measure under the hood and door jambs then compare with each panel on the car.

OK next question. What is a good reliable PTG that doesn't cost an arm and a leg. I'm just a weekend warrior. So thousands is out of the question. But a few hundred bucks, for a lifetime of measuring paint over my current and all future vehicles, I'm very open towards.
Click to expand...

Just get 1 of these. They’re only like $11 bucks on ebay and it works.

1e8c8e4823934f16d607ed3818819c28.jpg
 
SWETM said:
And that is the whole point as you get the measure on the primer and paint layers only. With a ordinary PTG.

Since we are on a sponsored forum I will link to AGO 2 cheapest PTG.

HighLine Meter Paint Thickness Gauge 2nd Generation

Defelsko Paint Thickness Gauge, Paint thickness meter, coating thickness gauge, auto paint meter, car paint meter
Click to expand...

I should have worded that better.

There’s no tell if the underside of the hood has had the same amount of primer and base as the rest of the car.

The door jambs are a more certain bet.
 
Several paint manufacturers as well as the paint manager for Acura, along with several well respected people in the industry all agree the up is in the top.5 mils.
 
Mike lambert said:
Several paint manufacturers as well as the paint manager for Acura, along with several well respected people in the industry all agree the up is in the top.5 mils.
Click to expand...

Are they also suggesting that taking just 16% of Clear off the average clear coat (3 mils) will cause the paint to fail via UV exposure?

I’d hazard a guess they’ve altered the explanation to make it simpler for people but have taken it a little far.

Removing clear is reducing the paint’s ability to resist UV rays. There will be an upper and lower limit of this threshold (don’t have the info on hand) which will dictate how much clear can be removed before UV rays will begin to penetrate and reduce the life of your paint.

I find it hard to believe that it’s just .5 mils before irreversible damage occurs and harder to believe that ALL the UV inhibitors are in the top .5 mls instead of it being a logarithmic scale of UV resistance.
 
How does the UV protection make its way to cure at the top of the clearcoat?


Maybe I’m just thinking about it like a complete noob, but to simplify it, let’s imagine for a second that clearcoat gets sprayed in 2 parts, 2 separate coats of clearcoat that are vastly different because the 1st layer of clear provides the gloss, while the 2nd coat provides the protection.

Either that or the clearcoat all comes out of the same can, but somehow after it’s sprayed into the surface the UV protection within it somehow gravitates to the top as it cures, and doesn’t finish curing until every last bit of UV protection has made its way to the top....

I dunno but both of those scenarios seem kind of unlikely.. But hey you never know, maybe they’ve figured out how to actually do that? I know Ceramiclear somehow achieves that, but I’ve never known it to be common among other car manufacturers.
 
Eldorado2k said:
How does the UV protection make its way to cure at the top of the clearcoat?
Click to expand...

The idea that the paint cures from the bottom up (aside from a thin layer exposed to air on the top side) isn’t implausible. The solvents in the paint vent from bottom to top which facilitates the hardening process so in theory, there is potential for particular chemicals to cure in the upper layers.

What seems implausible is that according to Mike Lambert and his mates at Acura, we’re just a few compounds away from no UV protection.
 
I’m just relating information that has been out there for years, I believe even Mr. Phillips has referred to it his articles. And just so you know, I have no “mates” at Acura. And given I’ve had several New Mazda vehicles in here with 2.5 mils total, you may indeed be a couple compounds as you say away from paint damage.
 
You must log in or register to reply here.
Back
Top