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How to Check Car Paint Thickness with a Coating Thickness Gauge?

In this blog post, you’ll read:Can coating thickness gauges accurately measure car paint thickness? Here’s the guide on how to check car paint thickness for its thickness and quality.

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Ever wonder if coating thickness gauges can accurately measure car paint thickness?

As car manufacturers, this question often occurs, especially during the quality assessment process. The level of protection the car enjoys is directly proportional to the thickness of the paint applied. Likewise, the maintenance cost in repainting the car after just a few years of use reduces significantly if the paint thickness is adequate. Hence, even car buyers sometimes require paint thickness checks to negotiate the price of the car. 

This post gives you all the information about how you can use a paint thickness gauge to check the thickness and quality of your car’s painting job.

Are you ready to learn more? We are ready if you are.


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I. Why Measure Paint Thickness on Automobiles?

A coating thickness gauge is an automotive paint inspection tool also known as a paint meter, and this is a tool that is essential to measuring the dry film thickness of an automobile. It is employed in estimating the product’s look, functioning, and life span. It is also an important measurement in the coating enterprise because it impacts the coating’s quality, process, and cost. 

So basically, the major reasons a paint thickness measurement on automobiles must be conducted include avoiding future repainting on a car because a proper inspection of the paint thickness increases the lifespan of the coating and eliminates a future recurrence of paintwork. It also reduces the automobile’s resale value in a case where the paint meter discovers rough spots patching or accidents underneath the automobile coatings.


II. Importance of Coating Thickness Gauge Calibration

Calibration helps manufacturers of coating thickness gauges ensure the gauge meets the required accuracy and specification. Therefore, it is crucial to calibrate a coating thickness gauge to regulate the material’s type, shape, and surface to be tested from giving out inaccurate information about the test results. 

For instance, the magnetic attributes of steel alloys differ, and the conductivity of distinct aluminum alloys and different non-ferrous metals also vary. These attributes can alter the dimension of a coating thickness gauge. It means that a gauge tuned on mild steel can have an unusual value for similar thickness coating on high carbon steel.


III. How to Calibrate Paint Thickness Gauge for Accuracy?

It is important to have a trackable coating thickness benchmark to get an accurate reading. With this set benchmark, you can then set the gauge to zero and adjust it to a known thickness standard at the optimum thickness. Also, you’ll need to measure an intermediate thickness and contrast the values with the actual thickness standard. Apparently, the inaccuracies are the variations between the reading value and the standard value, usually represented as the percentage of the reading. 

Accuracy in paint thickness gauge readings is paramount to its pricing. i.e., the more accurate the thickness gauge, the higher the cost. However, the coating application and other factors such as the operator’s knowledge of the machinery can also affect the coating thickness’s exterior volatility. And accuracy in paint thickness gauge is measured as the difference between the value readings and the actual coating thickness.


IV. How to Check Car Paint Thickness with a Coating Thickness Gauge?

The magnetic, eddy current, and ultrasonic principles are the three ways of measuring paint thickness in automobiles. 

The magnetic and eddy current have similar working principles, and we’ll consider how both work simultaneously. Their workings entail turning on the paint thickness gauge then placing the probe flat on the test surface. 

It is important to hold the probe steady for accurate measurement and calculation while displaying after the gauge beeps. Also, you may have to lift the probe at least 2 inches (5cm) from the surface at measurement intervals or leave it on the surface at the same location for frequent measurements of 2 seconds intervals. Lastly, you should not drag the probe across the measurement surface.

On the other hand, the ultrasonic measurement of coating thickness works by transmitting an ultrasonic vibration through a paint coating with a probe and a couplant administered on the surface. A bottle of a common glycol gel is usually attached to the instrument, after which the probe is placed flat on the surface to start measuring. A double beep or a green light alert for completion when the measurement is done, and the screen displays the last measurement. Multiple measurements can be made simultaneously by continuously holding down the probe on the surface. And finally, you must clean the probe with a soft cloth or tissue.


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➤ Related Article: How to Import Paint Thickness Gauges from China?



V. How to Use a Paint Thickness Gauge on Automobiles Effectively?

Whenever a paint meter is to be deployed, there are two main considerations to look out for. First are differences in paint thickness all around the automobile. This enables the operator to detect subtle changes in paint thickness, which could result from repairs or paint touching, or major bodywork such as clipping, which is welding two different halves of cars together.

Secondly, rust damage or collision spots should be considered as well, as different climates in different parts of the world can make automobiles rust in different parts and sections, depending on the climate of that country. If these variations are detected in one part, other parts must be measured, and reasons for the disparities should be explained and reasons for repainting.


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Related Article: How to use Ultrasonic Thickness Gauge?

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In a nutshell, automobile customers, especially auction buyers, immensely benefit from using coating thickness gauge as it helps them determine an automobile’s condition before making a deal for them.

While there are numerous advantages for users of coating thickness gauges, a coating thickness gauge must meet specified standards for accuracy and precision. Hence, the need to calibrate this coating thickness is an essential requirement. And it is necessary to have a trackable coating measurement standard to ascertain accuracy when measuring.

Finally, the magnetic, eddy current, and ultrasonic principles are the three major ways of measuring paint thickness in automobiles. We hope this post has been an eye-opening one, or hasn’t it?

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