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Measure 6 Layers of Automotive Paint with One Thickness Test

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Automotive paint

Automotive manufacturers continue to digitize and automate their operations to drive greater productivity and meet fast-changing customer demands, such as the adoption of electric, connected, and autonomous cars.

To support new developments, auto manufacturers must consider ways to streamline all their processes throughout production. One example is automotive painting—a process that requires multiple layers of paint and thickness measurements. Read on to learn about the challenges of measuring automotive paint thickness and how you can simplify this multilayered process with one thickness test.

The Challenges of Measuring Automotive Paint Thickness

Automotive paint is typically applied in four to five layers (or more) depending on the auto manufacturer and car color. A car’s paint job generally includes an e-coat, primer, base coat, and clear coat on a metal substrate. Some colors have an additional paint layer (mica).

Most current measurement options don’t let you see the individual layer thickness in one test. Some methods require you to measure the total thickness after each paint layer is applied and manually subtract to get the individual layer thickness. This process is tedious and time consuming.

Further, each car could have up to 100 or more inspection points depending on the make and model. Layer thickness is usually measured in the same spots to monitor trends over time.

Car manufacturers can shorten the production time in the painting of cars by:

  • Reducing the curing time between each paint application
  • Measuring paint layer thickness after all paint layers have been applied—rather than after each paint application

This improved workflow requires a technology that can measure the individual layer thickness and the total paint layer thickness in one test at the end of the production line.

A Faster Way to Measure Automotive Paint Thickness

The 72DL PLUS™ ultrasonic thickness gauge is an ideal instrument for measuring automotive paint thickness as it provides high-speed and high-frequency measurements of up to six layers. It also provides the individual layer measurements and total thickness of the paint layers with one test.

Car paint thickness gauge

72DL PLUS ultrasonic thickness gauge

Its intuitive software makes paint thickness tests easier and faster. For routine inspections, you can save a setup to recall it again. Simply recall the setup from the gauge to start an inspection in just a few seconds! Depending on your preference, you can set the unit of measurement on the gauge to mils, microns, or inches.

The M2104 (125 MHz) transducer is recommended for automotive paint thickness tests as it has a high enough frequency to measure multiple ultra-thin layers. It also has three plastic discs that allow the transducer to be moved over the inspection part without abrading the painted sample.

High-frequency transducer for automotive paint thickness measurements

M2104 high-frequency (125 MHz) transducer for automotive paint thickness measurements.

Multilayer Thickness Measurement of Automotive Paint—An Example

Here’s an example of a multilayer automotive paint application that has a clear coat, pigment, base coat, and primer. The screenshot below is from the 72DL PLUS gauge (High-Frequency model). It shows the paint layer thickness of four individual layers and the total thickness on the live inspection screen.

Automotive paint thickness gauge

Example multilayer measurement of automotive paint using the 72DL PLUS gauge. Layer 1 is the clear coat, Layer 2 is the pigment, Layer 3 is the base coat, and Layer 4 is the primer.

The 72DL PLUS gauge also offers five different layouts for data presentation—A-Scan, B-Scan, A/B-Scan, Trend, and Zoom—to help you better understand individual layer thicknesses. The screenshots below show some of the ways you can visualize paint layer thickness on the gauge using these layouts.

B-scan of an automotive paint thickness measurement
A/B-scan of an automotive paint thickness measurement
Trend analysis of an automotive paint thickness measurement
A-scan of an automotive paint thickness measurement

The 72DL PLUS gauge includes various measurement layouts to visualize thickness changes.

Another helpful feature is the guided inspection with a Custom part map. This map shows an image of the inspection part with the inspection points clearly marked on the part.

Inspection points for automotive paint thickness measurements

Custom part map on the 72DL PLUS gauge.

Learn More about Automotive Paint Thickness Measurements

Each multilayer paint application is unique and requires samples be evaluated. For more information or to request an evaluation of your automotive paint sample, reach out to us today. Our experts are happy to help.

Related Content

8 Reasons to Try the 72DL PLUS Ultrasonic Thickness Gauge

Brochure: 72DL PLUS Ultrasonic Thickness Gauge

Measuring Thin Single-Layer Material Using a High- Frequency Thickness Gauge and Transducer (Above 20 MHz)


Get In Touch

Product Specialist, Portable NDT

Archana Senthikkumar is a product specialist in the Business Strategy and New Business Development Division at Evident. She works closely with engineering, sales, and marketing and assists with the launch of portable NDT products. She has extensive experience working in the US and overseas. Archana holds an undergraduate degree in biomedical engineering from Avinashilingam University, India, and a graduate degree in biomedical engineering and biotechnology from UMass Lowell. She lives with her husband and two kids in Massachusetts.

June 30, 2022
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