What Causes Water Spots on Cars?

What Causes Water Spots on Cars? Water spots usually appear as whitish stains on the surface of a car. They might seem not so serious but they have the tendency of damaging your car paint just like any other unfriendly element will.

Water spots are hazardous to your car paint and can obscure the appearance of your paint making it look unappealing. As the name implies, water spots occur as a result of water splashing on the surface of your car. It could be from rain, sprinklers, drizzles, or the hard water used for washing your car.

They can threaten the aesthetics of your car paint if left unchecked.

In this article, we will be explaining to you all you need to know about water spots on cars.

What are Water Spots and how can you identify them?

Water spots are remnants of water that were allowed to dry on the surface of your car. There are traces of acid, dirt, mineral, and salt present in water and are deposited on the surface of your car through rain, washing, or splashes on the road.

Water spots are left on your car’s surface after the water has evaporated and the remains dry up on the car. But the case might be different if it’s immediately wiped off with a clean microfiber cloth.

When water dries up on any car, it leaves whitish or off-white, powdery, oval, or circle spots that may look easy to get it off your car using a cloth and water.

However, doing so can only be possible if it is not severe, but if it’s the contrary, you will need more than just cloth and water to bring back the shiny look of your car.

Water, especially hard water, contains minerals. It is an effective solvent that dissolves calcium, carbon dioxide from industrial and vehicle emissions, carbonates from rocks or mountains, metal, and other materials from the environment.

Some of these elements are absorbed into the atmosphere and they fall back as acid rain. Even the normal rainfall is contaminated with dirt and some compounds present in the atmosphere.

Also, most of the water used to wash cars can be described as hard water because some mineral elements like carbonates, calcium, magnesium, and metals have dissolved into it.

When you use this type of water to wash your car or it falls on it as rain, they leave droplets of these compounds on your car’s surface when the water has evaporated. This will cause damage to your car paint and clear coat if neglected.

Just like dark spots, scars, or acne will ruin a beautiful skin, water spots will ruin a beautiful car paint.

How do Water Spots Appear on Your Car?

Water spots appear on your car as a result of remnants of water drying up on the car. Technically, it is not just the water, but the contaminants, mineral, or acidic deposits that make up water.

And once your vehicle dries up, water spots appear as little white marks on the surface.

This water can come from several sources like rain, tap water, sprinklers, etc. Even your kids can play around your car with squirt guns and splash water on it.

When such water isn’t free of minerals or acidic compositions, it will leave water spots or marks on your vehicle because the unfiltered salts, dirt, and minerals like magnesium and calcium remain on the car after the water evaporates.

They corrode the paint and etch into your car’s clear coat leaving your car’s surface damaged and unattractive. Also, acid from acidic rain will leave acid deposits on your car which will eat up the paint and leave water spots on the surface.

Most causes of water spots are things that can hardly be avoided. For example, it can begin to rain while you are driving. You may also have a need to wash your car at a car wash which means repeatedly exposing your car to hard water.

What is important is to pay attention to the water droplets on your car. You should endeavor to wipe it off immediately and not let it dry on its own.

During summer, it is important to always dry up water on your car or use a detail spray to cover it up to prevent the sun from making it react with your car paint.

what causes water spots on cars

Causes of Water Spots on a Car

Water spots on your car are caused by a wide range of factors and activities.

When acid from acidic rain dries up on your car surface, it merges into the paint leaving marks on it. Acid rain contains a greater amount of sulfuric and nitric acids than the normal rain. It’s made of both the wet and dry acidic pollutants that could damage a car’s surface.

Acid rain is formed in the atmosphere when pollutants such as fossil fuels are burned and released into the atmosphere which mixes with oxidants and water vapor in the atmosphere and it’s converted to sulfuric and nitric acid. This acidic composition falls back as rain which eventually comes in contact with your car parked outside or while you are driving.

When the rain leaves the acid compounds on your car and the sun hits it, it eats into the car paint and even the clear coat which can cause mild, severe, or irreparable damages.

Another cause of water spots on your car is mineral deposits which happen as a result of using hard water. Hard water contains dissolved minerals like carbonates, magnesium, and calcium, or dirt.

Sometimes, if this water is not filtered, it leaves behind coarse particles of dirt or minerals which eat into the car paint and leaves spots on them. Washing your car with hard water at home or car wash and not drying it up immediately will lead to water spots caused by mineral deposits.

To curb this, you can add water softeners to water before using it to wash your car. Such water softeners use resin beads and go through an ion-exchange process to absorb the mineral components in the water and release sodium in the process.

Activities like driving in muddy or flooded areas, kids playing around the car with squirt guns, or leaving liquids on your car bonnet and not cleaning it up afterwards will leave water spots on your vehicle. The dirt and mineral compounds contained in muddy water will not only cause your car to be dirty but will corrode your car paint if neglected.

Another cause of water spots on your car is improper washing technique. Although this type of water spot is not severe and can easily be removed, it is worth taking note. Also, not rinsing off soap completely after washing will make the soap dry on the paint and can attract dirt.

What more? Not drying the car thoroughly after washing will cause the appearance of water spots. When water dries on its own, through evaporation, it will leave behind some mineral or chemical compounds present in the water, which will cause water spots.

It is important to dry off with a fluffy microfiber towel after washing and rinsing.

what causes water spots on cars

Categories of Water Spots on Cars

Water spots can be divided into three categories or stages.

They are:

Hard water spots on cars

This is the first stage of water spots on cars and it is known as “normal water spots.”

They are very common because it is almost inevitable to use hard water on your car. You can use it unknowingly or it can be used by car wash operators to wash your car.

Hard water contains magnesium, calcium, and carbonates which leave behind these mineral residues when it dries up on your car surface.

Rainwater is contaminated by airborne dust or smog which leaves dirt on your car when it dries up. This also forms the first category of water spots.

The water spot in this stage can be removed easily by rewashing the car and drying it with a microfiber towel.

Bonded Mineral

Excessively hard water and pollutants will cause this kind of water spot on your car.

They are more problematic than the first stage and a more severe stage of water spots. The bonded mineral is caused by water that has higher concentrations of minerals in it, it will bond to your car paint or coating and corrode your clear coat.

It can cause permanent damage to your car body if not removed on time even though it is not as easy to remove as normal water spots. They require the use of tools like hand-held rotary polishing tools, clay bars, polishing compounds, and a microfiber towel.

Etched in

This is the third stage of water spots on a car. This type of water spot is common in single-stage paint jobs that do not have a hard clear coat.

Etched in occurs when mineral compositions that came with rain dry on a car left under the sun for a long time.

When these minerals are not washed off on time, they etch into the surface of the paint and make a small water spot bigger.  This type of water stain can only be corrected using paint correction techniques.

Types of Water Spots on a Car

There are two major types of water spots and both tend to cause different degrees of damage to the car paint.

They include:

Mineral deposit water spot

Water contains minerals like magnesium, calcium, and carbonate. The number of minerals dissolved in water determines the hardness of the water and any water that exceeds the pH level of 7 is said to be hard.

Even the rainwater could come in contact with magnesium and calcium-rich rock and when it is used to wash cars, these minerals get deposited on the cars.

As the water evaporates, the deposits are left behind. When the car comes in contact with the sun, these deposits stick to the paint and form an off-white, web-like mark on the car body.

Some water utilities treat water to reduce the mineral composition and keep it within safe levels.

Acid rain water spot

Chemical compounds such as nitric and sulfuric acid are released from the atmosphere when fossil fuel is burnt.

The atmosphere also contains oxygen, carbon dioxide and some chemicals which when combined with sulfuric and nitric acid make it more acidic. 

Rainfall can bring this acid mixture to your car if parked outside and this will degrade your car paint.

Effects of Water Spots on Cars

One major effect of a water spot on a car is that it damages the car paint and sometimes extends to the clear coat depending on the volume of deposit, the type of water spot and how long it stays on your car.

When water gets to your car, corrosives and mineral compounds are left behind as the water evaporates. These compounds tend to create holes in your paint and sometimes eat into the clear coat.

Damaged clear coats and paint can be prevented if you pay attention to your car when there are water spots. Early water spots can be wiped off with a microfiber cloth or a detail spray.

Continuous exposure to hard or acidic water without cleaning it off will ruin your paint. If these cars are exposed to the sun too, the spots will become very hard and will require a more tedious procedure to remove them.

Car Wax that can prevent water spots

Car waxing seems to be an ideal way of preventing water spots after washing your car. Since you cannot completely escape mineral-rich water or rain, spray wax will help to get rid of water spots and prevent damages to your car paint.

Spray wax or detailers are produced specially to get rid of water spots and will not work if you intend to use them for basic car detailing.  Normal rainwater is not always as bad as hard water or acidic rainwater, so instead of re-washing your car, you can use a spray wax to quickly get rid of it.

Here is a list of car waxes that will prevent water spots.

  • SHINE ARMOR Fortify Quick Coat: This product is a hydrophobic spray wax. It is very effective because it does not let mineral or chemical residues remain on the car’s surface. It protects the paint and outer clear coat from etching and becoming dull.
  • 303 (30217-6PK) automotive spray wax and quick retailer: This works well on both dry and wet surfaces so it can be used immediately after washing or when the car is dry. It can prevent water spots for up to 3 months and does not cause any damage to the paint or clear coat.
  • Others include Abro Heavy Duty Silicon Cleaner and car wax, Super Gold Carnauba Car Polish, etc.
what causes water spots on cars

How to Get Rid of Water Spots on Your Car

There are different ways of removing water spots from your car. Here, we will be looking at two methods recommended by professional detailers.

White vinegar wash

White vinegar wash is an easy and effective way of removing water spots. This vinegar wash is effective for removing stage 1 and milder stage 2 marks.

The process is as follows:

  1. Apply the vinegar solution to the car surface with a spray bottle and wipe it with a microfiber cloth after some seconds. This should be done after thoroughly washing the car.
  2. If the water spots appear stubborn, they may require you to spray more rounds of vinegar solution and leave it to soak for 30-45 secs before wiping off.
  3. You should take this bit by bit, that is, spray a small portion at a time and leave it to soak before wiping it off with a clean microfiber towel.
  4. If vinegar is allowed to remain on the surface for too long, it will eat into the clear coat. Endeavor to wipe it off after a few seconds.

Two-buckets-and-a-beer wash

This process is effective for removing stage 1 water spots. It involves the use of different buckets for washing and for rinsing.

You will need;

  • 3 buckets – 1 for washing the wheels and tires while the other two should be exclusively for washing the car surface
  • 2 microfiber wash mitts – 1 specially for wheels and tyres while the other one for other surfaces of the car.
  • 1 bottle of automotive shampoo (low pH).
  • 5 microfiber towels for drying and polishing.

Follow the process here:

  1. Rinse the entire vehicle with water to remove any debris on the surface and pre-lubricate the surface for easy use of the wash mitt.
  2. Wash your tyres and wheels before moving to any other part. It is important to wash off the brake dust, ceramic, metallic, or any other coarse particle sticking to the wheels to prevent them from getting to the paint to cause scratches on the surface.
  3. Using two buckets, wash and rinse one section of the car at a time. Washing everything at once and rinsing it will not effectively remove the spots.
  4. When you are done scrubbing and rinsing, dry the entire vehicle with a fluffy microfiber cloth. This should be done quickly to avoid the water drying up on the car which might lead to the reoccurrence of water spots.

How to Prevent Future Occurrence of Water Spots on Cars

To avoid the repeated occurrence of water spots on your car, it is important to dry your car thoroughly after washing. You can use a microfiber towel for this process or a car dryer which is less time consuming and effective.

Another way to prevent a future occurrence of water spots is by using car wax. Car wax serves as a protection for your car paint. It prevents contaminants from getting to your paint. Wax will prevent your car from water spots and give your paint additional protection.

Other things that can prevent the occurrence of water spots include;

  • Using water repellants. This will coat the surface of your car and give it a protective finish.
  • Applying sunscreen to your car before going out on a sunny day will prevent water spots from building up on your car.
  • Water spot removers are also an effective way to remove and prevent water spots from your car. A good product is Meguiar’s Water Spot Remover.

Recommended Products for Water Spots Removal

Water spot removers will help revive the aesthetics of your car. they will remove water stains from the surface of your car and maintain your car paint. There’s a wide range of products available for removing water spots, some bestselling brands are;

  • GlasWeld ProClean Hard Water Spot Remover.
  • Mother’s 06712 California Gold Water Spot Remover.
  • Boat Bling Hot Sauce Hard Water Spot Remover.
  • Carfidant Scratch and Swirl Remover.
  • Chemical Guys Heavy Duty Water Spot Remover.
  • Wet or Waterless Car Wash Wax Kit.
  • Boat Candy Speed Gloss Water Spot Remover.
  • Meguiar’s Extreme Water Spot Detailer.
  • Duragloss 506 Water Spot Remover.
  • 3D Eraser Gel Water Spot Remover

Frequently Asked Questions

Are water spots harmful to the car paint?

Water spots are as harmful as every pollutant that gets in contact with your car paint. Water has minerals, chemicals, debris and other contaminants that can ruin your car paint. Water comes in contact with your car daily. It can be in form of rain, dew, or sprinklers. When this water evaporates, it leaves some mineral or chemical residue on your car which can corrode your paint.

Will rubbing compound remove water spots?

Rubbing compound is a good option for removing tough water spots. If the water spots are not severe, you do not need to use compounds. Vinegar wash, car wash mitts, and water with a microfiber towel for drying will easily remove these minor water spots. When choosing a rubbing compound, ensure it is one with a very fine texture. A coarse rubbing compound will remove the spots but will leave scratches on your car paint.

How long will it take water spots to damage my car paint?

Your car might have less severe water spots which can be easily removed but if you ignore them, it will not only ruin the appearance of your car but will damage your paint as well. Some water spots will not take so long to damage your car paint especially when your car continuously comes in contact with the sun. The sun heats the mineral components deposited by water on your car and makes it more dangerous which will cause rapid damages to your car paint. If the water spots are from acidic rain or mineral deposits, contact with the sun will cause these spots to etch into the paint and even to the clear coat, especially if it is left for a few days which will also make it difficult to remove.

Why does my car get water spots easily?

Your car will easily get water spots because they are always exposed to water. Water spots could come from rainfall, dew, nearby sprinklers, washing with tap water, or any water which normally has mineral components in it. Water and water spots cannot be completely avoided. There will always be rainfall, dew, or snow and there will always be a need to wash your car. You only need to be cautious and take good care of your car. Ensure you dry it properly after rainfall or re-wash it and use waxes or detail spray.

Do water spots go away on their own?

Water spots will not go away on their own. If it is a mild water spot you might need to rewash and properly dry your car. Repeated exposure to hard or contaminated water and negligence of water spots on your car paint will make these spots more difficult to remove. When it gets to this extent, rewashing and drying will not remove the spots. You might need to use water spot removers to get it off.

How do I prevent water spots on my car?

Water spots on your car are detrimental to your car’s paint and finishing. Aside from making it look dull and unappealing to the eyes, it can also cause temporary or permanent damages to your car’s surface. You can prevent water spots on your car by drying the surface properly with a fluffy microfiber towel after washing, avoiding washing your car in direct sunlight. You can also dry with a car dryer and use a detailed spray after this. Other methods have been mentioned in the article.

Will a normal rain cause water spots?

Yes! Rain can cause water spots on your car. Rainwater mixes with several contaminants present in the atmosphere. It could be dust, carbon dioxide, nitrogen or sulfur. All of these components mix with rain and fall to the earth. When these water droplets get to your car, it leaves these components on your car surface while the water evaporates. Any dirt or mineral compound on your car will cause water spots. It is important to wash your car after several days of rain to prevent the build-up of dirt and mineral on your paint which will lead to water spots.

Are water spots on cars permanent?

Not all water sports are permanent. Some water spots can be easily removed by just rewashing your car and drying it properly. Water spots can also be removed by using commercial water spots remover to wash and remove spots. However, some water spots can become permanent. If water sports are left on the car for a long time, and your car constantly gets in contact with the sun and more minerals, the water spots can cause permanent damage to your paint job and will etch into the clear coat. At this point, all you might have to do is re-paint and coat your vehicle again since the damage is huge and it might not be easy to remove all the water spots.

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