Understanding Acid Etch Marks on Your Car: Causes and Solutions

Have you noticed small, stubborn spots on the surface of your new car that just won't wipe away? These persistent blemishes are known as acid etch marks, and they can be a frustrating issue for car owners. Understanding the causes of acid etch marks and exploring solutions to prevent and address them can help maintain your vehicle's pristine appearance.

What Are Acid Etch Marks?

Acid etch marks are small, permanent spots that appear on a car's surface. They are often caused by environmental factors such as air pollution and acid rain. When acidic substances come into contact with a car's paint, they can leave behind dusty deposits that bind to the surface. If these deposits are not promptly removed, they can become permanent, resulting in unsightly etch marks. 

Even major automotive suppliers and manufacturers face this issue. For instance, cars arriving at shipping ports near Jacksonville, Florida, were found to have acid etch marks. Investigations revealed that air pollution in the area was the culprit. The combination of industrial emissions and acid rain contributed to the formation of these marks on the vehicles' surfaces.

Q-Lab: The Solutions Provider for Acid Etch Marks

To develop effective solutions for removing acid etch marks, it is crucial to recreate the harsh conditions that cause them. This involves conducting controlled experiments that simulate real-world scenarios. 

Through a collaborative effort between Q-Lab and an automotive OEM customer, a specialized testing protocol was developed. This involved using a secondary spraying system with the Q-SUN Xe-3 tester to apply an acid solution to the test specimens. The near-horizontal flat array format of the Q-SUN Xe-3 prevented runoff, ensuring that the acid solution remained on the surface, closely mimicking real-life conditions.

By replicating the harshest 12 weeks of environmental exposure in Jacksonville within a 400-hour accelerated laboratory test, scientists could quickly formulate and retest specimens. This accelerated testing process allowed for the rapid development of coatings that are more resistant to acid etch marks.


Acid etch marks can be a persistent and frustrating issue for car owners, but understanding their causes and exploring effective solutions can help mitigate their impact. Through advanced testing and collaboration, the automotive industry continues to develop more resilient coatings to protect vehicles from environmental damage.

Are you dealing with acid etch marks on your vehicles?

Maha offers Q-SUN Xe-3 tester that  can help you combat acid etch marks and maintain the integrity of your automotive coatings

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