9 Tips On How To Avoid Water Spots

Detailers often blame chemicals for leaving white spots on the car after washing.

“Foam doesn’t wash,” and  “I tried 10-15-20… shampoos, but water spots are still thriving.

The truth is shampoo affects spots less than any other factor. This article reveals the TOP 9 things to avoid water spots.

Without further ado, 9 tricks to avoid water spots:

  • Use only high-quality water
  • Washing temperature matters
  • Pick suitable chemicals
  • Wash your car fast & effective
  • Don’t mess with water pressure
  • Consider an alternative washing technique
  • Dry the paint carefully
  • Get your car coated 
  • Don’t neglect the post-washing period 

Now let’s talk in detail about each bullet. 

Use Only High-Quality Water

Water quality is one of the five factors of washing success.

If you use water that is too hard, no product will help prevent water spots.

Getting spots now? Think about a water filtration system. After all, it’s not just about your car; it’s also about your health. 

Can not afford to buy a filter? Try using distilled water. This water has no minerals that create water spots on the surface of your car. 

Alternatively, you can outsource the wash.

Most car washes have professional filters that purify the water and make it as suitable as possible for washing without water spots.

Washing Temperature Matters

Use water temperatures in the 85°F to 105°F range. This temperature is splendid for your car’s paint.

In summer, you can raise temperatures to 110°F, and in winter, water not colder than 80°F is fine.

Bear in mind that range varies depending on many factors. Take it as a flexible rule which can involve exceptions.

Before you start washing, make sure the car body is about the same temperature as the environment.

If you’ve used the car recently, it’s best to give it a couple of hours to cool down and then start washing. 

If the temperature difference between the car body and the water is too big, you can damage the paint.

Micro paint particles are capable of expanding and contracting depending on environmental conditions, which affects the absorption of minerals from the water.

For example, if you wash a hot body with cold water, the chances of water spots multiply. 

Pick Suitable Chemicals

Hand wash requires a shampoo with a neutral pH, while touchless washing uses more alkaline shampoos.

And what shampoos should you use to remove or prevent water spots?

It would be logical to assume that since you’re doing a touchless wash, you should use alkaline shampoos, right? No.

In most cases, water spots are salts that are neutralized by reacting with acids.

So you should use acidic shampoos (with a pH value below 7.0).

When in contact with water spots, such foam reacts at the molecular level.

The result is formed substances insoluble in water, which can easily be washed away with a jet of water. 

Alkaline shampoos, however, involve a reaction of exchange between the shampoo and water spots.

Simply put, they are much less effective when it comes to removing water spots specifically.

If you are unable to get an acidic shampoo, try utilizing an alkaline active foam solution at the upper dilution limit.

For example, the manufacturer specifies a dilution of 1:4-1:8. Try 1:3-1:4 instead.

The soothing components of active foams in high concentration can dissolve salt deposits more effectively.

Want to know more about detailing supplies? Check out this 101 detailing products guide.

Wash Your Car Fast & Effectively

No matter how safe and “neutral” shampoos are, chemistry is chemistry. Keep your wash time minimum.

Read the label on the shampoo and strictly follow the time frame. Generally, it’s not advisable to leave the foam on for too long.

The longer the chemicals are on the surface, the more chance that mineral deposits will show up on your paint as water spots.

Don’t Mess With Water Pressure

Use a standard pressure that is safe for washing. The classy pressure is between 1300 and 1700 PSI.

Going beyond that, you run the risk of damaging the paint.

Higher pressure is more aggressive on the coating; it cuts deeper layers of paint.

In practice, this means that the salts will deposit deeper, being harder to wash off.

If you want to avoid water spots, set the machine to medium pressure (approximately 1500 PSI).

Consider An Alternative Washing Technique

Touchless wash is terrific and prominent. But there are other methods just as good. 

One of them is a waterless wash. This technique is referred to as washing literally without water. No water = no water spots.

Alternatively, you can use an old-fashioned hand wash to remove water spots manually.

However, this method deals only with salts, meaning that it can be used during the winter and early spring.

Summer brings other chemicals behind water spots. (detailed explanation at the end of the article).

Dry The Paint Carefully

Washing is half the battle, but it’s just as important to dry the surface of the car and go over the body with a rag again to remove salt residue and excess liquid (which could potentially turn into a water spot).

To avoid spots, use some soft and dense microfibers. Fold them in half twice (in 8 pieces) and wipe the entire body.

Use only a circular motion and work on one part of the car at a time. There is no need to smear the remaining dirt all over the vehicle.

Get Your Car Coated 

After you’ve thoroughly washed and dried your car, it’s time to think about what you can do now to prevent water spots?

The comme il faut answer is to apply a thin layer of wax to the paint.

The positive effect of wax is due to the properties of the waterproof resins and polymers.

They reliably protect your car from adverse environmental factors such as acid rain or smog. 

The logic behind the application is simple: the wax creates an extra layer that serves as a shield for your paint.

First, it’s harder for the salts to attach to the wax, which means there’s much less chance of seeing water spots.

Second, even if the salts do stick, you’ll wash the wax layer off the next time you wash your car, and it’ll be ultimately clean.

Hint: If you apply wax on top of water spots… Don’t do that. The water stains reduce the reflectivity of the paintwork.

No matter how much wax you apply, it won’t shine cool.

Read this article to know what makes waxing such an important matter in the detailing world.

Don’t Neglect The Post-Washing Period 

You’ve washed your car and waxed it, do you think that’s the end of your struggle with water spots? Well, it isn’t! 

Automatic watering systems (sprinklers) and unexpected rainfall are sure harbingers of water spots.

It all comes down to poor water quality.

Keep your car either in the garage or under a carport; during working hours park in the buildings, under the ground, or at least away from the irrigation systems.

Don’t forget that in some states roads can be washed by special trucks.

A highly toxic chemical barrage is the last thing your paint desires.

What Causes Water Spots After Washing A Car?

Quick Answer

For the most part, water spots appear due to mineral contamination, rare washing, and poor environmental conditions. Depending on the chemical composition, water spots are divided into two types: grease film and salt deposits.

Grease Film

Grease (oil, hydrophobic) film is a deposit caused by hydrophobic (water-fearing, insoluble, and not wettable) substances mixed with mineral impurities on the paintwork.

What causes: in wintertime the amount of hydrophobic (oil) pollutants is sky-rocketing.

The source of these pollutants is car exhausts, unburned fuel, especially from older diesel engines.

This is a problem of busy highways and large cities — unburned diesel fuel, oil, soot, and other toxins that fly out with the exhaust.

All this is deposited on the road and cars, mixed with dirt, acquires the consistency of bitumen / solidol, hardens in the cold, still lifted by the wheels, and again deposited on the car.

How to recognize: The car becomes like a dirty, greasy dish that is difficult to clean in cold water.

Rubbing the paint results in smeared (instead of removed) scale.

Salt Deposits

Hardness salt deposits look like whitish, rough spots, especially noticeable on darker cars.

The deposit is clearly visible on the side and rear windows of the car, they are not crystal clear and rough after washing.

The deposit is also visible on the windshield outside the area of the wiper blades.

What causes: at infrequent washing in the winter time, moisture from pollution on the body surface evaporates, bypassing the liquid phase, thus forming a hard and dry scum of salts.

Also appears due to the use of hard water.

How to recognize: the car is unevenly covered with a layer of scale, the largest accumulation near the arches and on the sides.

When rubbing the clean, wet surface with your finger, the scale is not rubbed, it remains in place and the surface is slightly rough.

The scale is most common on cars that have not been washed for a long time in the winter, sometimes 2-3 months.

The mass appearance of this scale comes with the first days of spring.

Key Takeaways

  • Use the average pressure of 1300-1700 PSI 
  • Rinse your car with distilled water 
  • Waterless wash less likely causes water spots 
  • Acidic car shampoos work better than alkaline ones (in terms of water spots)
  • The best temperature to remove spots is between 85°F to 105°F
  • Hand wash is a terrific technique during the winter (to remove water spots)
Jan-Lucas Ganssauge
Jan-Lucas Ganssauge