December 5, 2023

Since the advent of companies like Carfax and AutoCheck, automotive shoppers have relied on vehicle history reports to determine if a car has been in an accident.

Here’s the thing: not all accidents show up on these reports.

One DIY solution? Get the tool the pros use: a paint meter.

It’s time to learn how to use a paint meter, why it works, and what it can (and can’t) tell you. It could help you to avoid a costly mistake.

What Is a Paint Meter?

A paint meter is a handheld device that uses a magnet to detect the thickness of paint.

The magnet of a paint meter

If you hold the paint meter against any steel panel of a vehicle, you’ll get a reading like this:

A paint meter reads 4.5 on a red hood of a vehicle.

The distance between the magnet in this paint meter and the metal of the hood is 4.5 mils.

That means the thickness of the paint is roughly 114 microns. One mil equals 25.4 microns (automotive paint is measured in microns). Most vehicles have a paint thickness between 67 and 198 microns from the factory.

The Google conversion of millimeters to microns
Image Credit: Google

Depending on how your paint meter reads (mils or microns), you’ll multiply or divide by 25.4 to convert between the two.

Whether you want to inspect an EV or ICE, you can use a general-purpose paint meter because paint is paint. However, paint isn’t applied evenly to all surfaces of a vehicle. Those exposed to direct sunlight (trunk, roof, hood) often have thicker layers of paint. That’s why it’s critical to know how to use the paint meter properly.

How to Use a Paint Meter

Because paint varies between manufacturers, you have two choices.

If you’re buying a Ferrari, you’ll want to find out the factory specifications for the model you’re considering. If you’re looking at a used Kia, you can probably figure out if the vehicle has been repainted using a few simple heuristics.

First, record the readings on each panel, measuring the same panel in multiple spots.

Second, analyze your findings. A repainted panel will often have inconsistent readings. For example, this Lexus front quarter panel has three different readings.

Repainted panels will yield higher readings than factory paint. The readings on this Lexus indicate it has been repainted (and I know it has been).

As a general guideline, anything over eight mils is cause for question. That’s because when a vehicle is in an accident, it goes to a body shop. Unlike at the factory, it won’t be painted by high-end machines but rather by technicians with spray guns. Even the best body shops will apply more paint (meaning thicker paint, meaning a higher paint meter reading) than the manufacturer.

To borrow an example from the art world, if you’ve ever seen a Van Gogh in person, you know how textured and chunky the paint is. Van Gogh used his fingers in a technique called impasto to apply thick and varying layers of paint to his masterpieces.

Think of car paint as the opposite of a Van Gogh. Because machines apply it at the factory in an ultra-thin uniform layer, deviations and high readings indicate it’s not original.

What Can’t a Paint Meter Tell You?

Bumpers are typically made of plastic, so magnetic paint meters are of no help. With bumpers, it’s best to check the seams for uniformity. Uneven gaps are often indicators of shoddy bodywork.

But remember: just because a panel has been painted doesn’t mean the vehicle has been in an accident. Automotive paint consists of three layers: primer, base coat, and clear coat. Sometimes one of these layers is improperly applied at the factory.

For example, Honda extended the paint warranty on certain vehicles because the clear coat was peeling off. In addition, you can check with National Highway Traffic Safety Administration (NHTSA) for service bulletins to determine if a vehicle has a factory defect.

It’s also important to consider the severity of the accident. For example, many cars are involved in minor fender benders that in no way compromise the vehicle’s safety; others are serious.

A grey Honda Civic coupe is in a serious accident that rolls it upside down

Yet, many cars declared “total losses” by insurance companies are purchased by body shops, repaired, and sold again.

If your paint meter indicates a vehicle you’re thinking of purchasing has aftermarket paintwork, it’s best to involve a qualified professional. They’ll put it up on a lift and examine the frame and other key safety components, such as airbags, to ensure the vehicle has been properly repaired.

Do not listen to your Uncle Larry, whose sole qualification is that he can change his own oil. Only a professional can tell you what kind of accident the vehicle was involved in, the damage’s extent, and the repair’s quality.

Why Some Car Accidents Don’t Show Up on Vehicle History Reports

If you’re using apps to search for the best new or used car, you know there’s a ton of information to sift through. These apps often allow you to view vehicle history reports for used vehicles. Given that we live in an age where we can report incidents on Apple Maps, it might seem surprising that not all accidents show up on these reports.

Here are two commons reasons that may make you want to add a paint meter to your toolbox:

Not Reported

There are many reasons an accident might not be reported. Some are by chance, and some are deliberate.

Increasingly, vehicle owners know that an accident on their vehicle’s history report can lower its trade-in value. They will opt to pay out of pocket at a body shop that doesn’t report its work. If there’s no police report, no insurance claim, and no records from the body shop, very often, no one will be the wiser.

Outdated Technology

Some rural regions are operating with the same technology they’ve had since the 1950s. Sometimes a police department that previously kept everything on paper decides to digitize and report its records. That’s why it’s possible to buy a vehicle with a clean history report and then later have an accident show up. While owners are understandably upset when this happens, it’s not an infrequent occurrence. That’s why a paint meter can easily pay for itself.

How Much Do Paint Meters Cost?

Though paint meters used by car dealerships, body shops, and reconditioning facilities can cost anywhere from $500 to over a thousand dollars, the everyday car shopper doesn’t need to spend anywhere near that much. A meter like the Thickness Gauge VVV-Group CM-205FN can be bought for less than $70.

Given that a vehicle is one of the largest purchases many people make, a paint meter can be a good investment. Like a stud finder or cordless drill, you won’t use it every day, but when you do, you’re glad to have it.

While some paint meters can be used on aluminum and even plastic, these tools aren’t necessary for the average car buyer looking to ensure they’re buying a safe vehicle. Knowing how to use a magnetic paint meter and what to look for can help you to identify a car with previous paintwork. Combined with the inspection of a qualified professional, you avoid any unpleasant surprises.


Leave a Reply

Your email address will not be published. Required fields are marked *