How to Avoid Hard Water Spots on Your Car

Someone drying the hard water spots off a car's windshield.

Any type of water contains minerals like magnesium and calcium. Hard water spots appear on your car because as the water dries, it leaves behind traces of these minerals. If you continue to allow this to happen, the minerals along with other dirt and debris will eventually affect the surface and overall paint job of your car. There are steps that you can take to prevent hard water spots from damaging your car.

Wipe the Car Exterior Dry Every Time it Gets Wet

The easiest and most effective way to prevent water spots is by wiping your car dry after a wash, rainfall, or any time it gets wet. Use old towels and microfiber cloths to wipe the water off, and do this each time after the rinse stage of washing. Make sure to dry the painted surfaces, chrome, and plastic parts of the car. Go over each part several times so no streaks of water are left as these can also leave residue on the car's surface.

Keep the Car Sheltered from Rainfall

Ground water sources can contain even more minerals than rain water, as well as dirt particles, which increases chances of marks or, what's worse, “etching” of the paint finish. Etching is where minerals or debris get under the paint and cause small scratches to the unprotected parts of the car’s surface. If possible, store your car in the garage during rainstorms, and keep your car away from sprinklers or other potential water sources.

Keep the Car Sheltered from Extreme Sun

A car under a carport to protect the paint from the sun.

High temperatures can speed up the process of corrosive water spots developing as the sun bakes off water faster, leaving only the residue behind. The more the spots are baked on, the more difficult it becomes to remove them. (It’s not recommended to let your car roast in the sun at any time—even when you aren’t planning on washing it.) On the same note, never wash your car in intense heat or sun, and instead wait until late afternoon or early morning when the suns rays aren’t as potent. Think of the car’s paint finish like your own skin. The more it’s left exposed, the harsher the damage will be.

Use a Vinegar Wash to Remove Water Spots

Rather than spending a lot of money on fancy water spot cleaners, consider using white vinegar as your main water spot removal solution. Not to be used as your main car soap, vinegar helps to cut the pH levels of hard water and will remove stubborn water stains that have dried. After washing your car with a proper car soap and drying it, mix equal parts vinegar to water (distilled is recommended as it will not contain as many minerals as regular tap water) and wipe all over the car with a sponge. Rinse well afterward with distilled water if possible, and then wipe it dry with microfiber cloths. Remember that vinegar will also remove any wax or sealant so you will have to re-apply this protective layer after drying.

Use a Clay Detailing Bar to Remove Minor Etching Marks

While vinegar is great at removing the water marks, if they were left on for too long you may notice that your car has suffered from etching. If water spots etch the paint finish, you’ll need to do a little damage control and a great product to rectify this is a clay detailing bar. First, wash the area with vinegar or soap and dry the surface. Next, lubricate the area with a preferred quick wax product and rub the clay on the affected spot. Buff with a microfiber towel until you are satisfied with the results. Make sure to follow the instructions of this product carefully, and only use it if etching marks are minor.

Use a Good Sealant or Car Wax

A sponge with wax on the surface of a car.

A good sealant or wax is the final step in preventing water spot damage. After a proper wash with soap or vinegar, dry the surface thoroughly and apply a good wax product. This will prevent water damage to the car’s surface by causing the water to bead and run off. Continue to wipe your car dry after any rainfall or water spray even if you use a wax or sealant, especially on areas where you do not use the wax, like lights, bumpers, and windows.

We like to think that water is harmless, and for the most part it is, however it will do damage to your car if left to surface-dry. Using a good quality car soap will help keep the paint finish clean, however all is lost if you let water spots go unchecked. If you want to maintain your vehicle’s paint finish, drying any water spots and protecting it with these maintenance tips will keep it looking brand new. Water spots may seem innocent enough, but in reality, they can wreck your car over time.