What Causes Swirl Marks on a Car

If you bought a new car ( or a relatively new car) you may be wondering how exactly do swirl marks form and how can I prevent them? This is a very common occurrence with most vehicles, and it’s something that can be difficult to avoid.

In order to avoid them,  you’ll want to follow a few best practices. In this blog post I’ll break down what causes this circular pattern to form, how to prevent swirl marks, and an easy way to remove them from your vehicle.

What exactly are swirl marks?

Swirl marks are basically tiny circular micro-scratches formed on a vehicle’s clear coat. Swirl marks are typically formed by someone washing a portion of their vehicle in a circular motion, with either a dirty wash mitt or without proper lubrication.

These circular scratches form whenever a rock or small piece of debris makes contact with the clear coat. Whenever your car’s clearcoat gets scratched by debris, a jagged cut or a V-shaped cut is etched into the layer of clearcoat at a very microscopic level. Below is a basic diagram that explains this concept.

To the human eye, the scratch appears to be a white or faint white color because the sunlight reflects off of this jagged edge, bouncing light back to the surface. What you en up seeing is a faint line or in this case, many tiny circular lines.

swirl mark anatomy

Source: NIST.gov

Why swirl marks are circular

Swirl marks tend to be circular because like I mentioned, most people use circles whenever running a sponge or a wash mitt over a vehicle. Whenever a small piece of debris is trapped in a wash mitt or sponge you may not even be able to see it.

Using a circular motion (even with plenty of lubrication) I am not a huge proponent of, simply because more friction is created as opposed to side to side passes.

The idea is to slide the dirty suds off your vehicle. Using a polisher (or applying polish in a circular manner) is different, since the goal is to blend rather than remove.

How to prevent swirl marks from forming on your car

Adam's Non-Scratching Microfiber Wash Mitt

The best way to prevent swirl marks from occurring on your vehicle is to apply proper lubrication. If you’re ever going to use a waterless car wash product the most important factor is the amount of lubrication that’s added to the product.

Lubrication helps to form a slippery surface between your wash mitt and the layer of dirt clinging to the clearcoat.

As long as you have plenty of water and lubrication, you reduce the risk of swirl mark formation, due to the fact that you’re not taking a dry object and running it across a dry surface.

The reason many people choose to apply soap using a touchless method

foam cannons and guns

Many detailers and professional choose to use a device called a foam cannon to apply soap since this method eliminates the need to dip a wash mitt in a bucket to apply more suds.

These devices (which I wrote about in this blog post here) attach to a pressure washer lance and basically spray foam from a pressurized canister onto the vehicle.

While it’s a good idea once the foam is on your vehicle to use a wash mitt (to help break the static bond that sometimes keeps dry dirt from sliding off) the fewer times that you contact your vehicle the better.

Conclusion

In conclusion, swirl marks are really common and almost impossible to prevent unless you are extremely careful. The good news is they can be removed!

How to remove swirl marks

A quick way to remove swirl marks is to simply use a polish and a dual action or orbital polisher.

Swirl marks can be removed using an abrasive that basically sands away the jagged clear coat layers that cause your eye to see tiny circular marks. With a little practice you’ll be able to remove swirl marks, scratches, and so many other common imperfections that you may find on a vehicle over time.

For more tips like this and to expand your knowledge of auto detailing, get your free copy of my eBook, 25 Essential Auto Detailing Products for Beginners and be sure to subscribe to our YouTube channel.

Happy detailing!

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