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Are Public Car Washes Bad for a Vehicle’s Paint Job?

A black car is washed at a public car wash.

I don’t drive a car anymore, but when I did, it was clean and shiny. Resale value is much better if your car glows in the sunlight. Other than a house, a car is one of the biggest expenses most Americans take on.

It’s just common sense to take care of it. Most drivers wash their cars once a week. The dirt and grit of gravel pit the paint and dulls the shine. Lots of drivers wash their cars at home, but some prefer the convenience of a public car wash.

However, this damages the clear coat and the paint on your car. Why are they bad for a vehicle’s paint job?

Types Of Public Car Wash

Different methods of publicly cleaning a car carry their own dangers for your car’s paint job. The self-serve type, where you use a washer wand to soap and rinse your car, won’t hurt the paint. They just use soap and that’s all. Other types, though, use different materials to clean a car:

1. Drive through point oh

Car is washed using cloth at public car wash.

These use cloth brushes to clean a car. However, if they’re not thoroughly cleaned before washing the next car, the brushes will track dirt and grit from the last wash along with your car’s paint job. This damages the clear coat and paint job.

2. Drive through point one

Car is washed using a brush at public car wash.

Some drive-throughs use brushes made of stiff fibers like nylon or plastics. These obviously scratch the paint on cars. 

3. Touchless

Worker cleaning a car using a spray water gun.

These use jets of water to wet, soap, and rinse a car from every angle. The snag to that is that the strong detergents and chemicals used will damage the finish on a car over a period of time.

Not only that, but they often leave nooks and crannies untouched. The dirt and grime will damage the car’s paint job.

4. Full service

Woman hand wiping drying a car using yellow cloth.

A car wash employee will drive your car onto the conveyor belt, send it through the wash, and then wipe dry your car. Beware the employee using dirty cloths to wipe dry your car.

They’ll wipe back on the dirt and grime the car wash just washed off. I’d politely thank them and then drive the wet car away.

How Public Car Washing Chemicals Work

Laundry soap works by first removing the dirt from the clothing, holding it suspended while washing, then it uses friction to clean the cloth. The load is then spun out.

A fabric softener is often added to the load to remove all the soap before the load is put in the dryer. Sometimes extra dirt-removing oomph is added with products like Oxyclean. 

Now let’s apply that to a car wash. The friction types of the car wash, like tunnels and conveyor belts, use mostly soap and water.

The touchless type, though, uses detergents with a balanced pH/alkaline level.  They use more and stronger chemicals to replace the friction of the brushes.

How The Chemicals Interact With A Car’s Paint

Peeling paint of a blue car.

Car wash chemicals first interact with the water sprayed on the car. The stages of a touchless car wash use stronger chemicals due to not using brushes. When they mix with the water to wet your car, the paint is introduced to those chemicals. 

It will take a little time, but the clear coat will be eaten away first. The car suddenly has no shine. Then comes the paint. Small spots are eaten away, which leads to larger spots being eaten away.

Now the car is down to primer in certain spots. Your car needs a new paint job.

What’s The Answer?

Washing your car at home will protect it from the chemicals and dirty brushes used in public car washes. Here are some tips:

The Car

1. Do wash your car in the shade. Direct sunlight, especially on hot days, will dry the car washing solution. This means you’ll be washing off the washing solution twice.

2. Don’t wash your car until it’s cool. If you’ve been driving it, the heat from the car will dry the washing solution. You’ll be washing the car twice.

3. Rinse the car thoroughly before cleaning it. This removes loose dirt and grime that could scratch your car if you begin rubbing washing solution on it. 

Cleaning Technique

4. Work the cleaning solution up into a sudsy lather. It will lubricate the painted surface.

5. Wipe the cleaning solution in a straight line instead of in a circular motion. Circular motions leave swirl spots on the paint job.

6. Only work on one section at a time. If you wash the panels from front to back or vice versa, some of the soap will dry before you have time to rinse it. It will leave marks on the paint job.

Products To Use

7. Do not use household cleaners to wash your car. The chemicals were designed to lift oil from dishes, dirt from laundry, or grime from mirrors and glass tabletops. Use specially formulated eco-friendly soaps to wash your car.

8.  Use a natural sponge, like a lamb’s-wool mitt or a microfiber cloth, to wash your car. Keep a separate bucket with clean water for rinsing the sponge or cloth often. You don’t want to spread dirt you’ve already cleaned off the car back onto another panel.

Drying The Car

9. Don’t let the car air dry. It will give the car watermarks. Wipe the car down with clean cloths.

10. Use chamois or microfiber cloths. These absorb more water. You’re going to need quite a few. Dry the car straight across and not in circles for the same reasons mentioned above. It will leave spots.

Final Thoughts

Chemicals are a fact of life. The fact that they do more damage than they do good is slowly being recognized and dealt with by using eco-friendly or natural products. It’s the same with washing our cars. The chemicals mix with the water to coat your car and wash it.

After a few times using public car washes, you’re going to need a new paint job. Save yourself the agony and wash your car at home. Using eco-friendly products and a few washing techniques will save your car from a chemical nightmare.