
Rain is not 100% water. It contains minerals, pollutants, etcetera!
When rainwater dries up, it leaves impurities on the car surface AKA acid marks. This eventually corrodes with the car paint.
If left for a long time, these marks can cause costly and sometimes lasting damages on the car surface.
Remove it before it’s too late! Here are three methods you can try, starting from the least aggressive.
Method 1: Claying
An automotive clay bar can eliminate hard bonded contaminants or microparticles on the paint surface. Clay bars are widely available online and easy to use. Here’s how:
Knead the clay – knead the clay to form a flat round clay (burger patty like).
Spray a soapy solution – Remember to do this one area at a time. Use your hands to locate the rough spots. Spray the soapy solution as needed. This acts as a lubricant to prevent scratching the paint.
Glide the clay against on the paint surface – Carefully rub the clay in a single direction either horizontal or vertical.
Last, rinse and wipe the area.
Method 2: Water spot remover
You’ve probably seen tons of these online. This ideal for deeply seated marks. Just be extra careful when using chemicals like this.
If you are not 100% sure, do not proceed and take your car to a professional auto detailer.
Water spot removers contain strong chemicals and can damage your car if applied incorrectly. Follow the product instructions carefully.
Protective gear: Safety first! Wear chemical resistant gloves, face/gas mask, and eye protection.
Use a microfiber or sponge applicator: Pour a slight amount of liquid on a microfiber or sponge applicator.
Apply in a small area: You need to do it in small sections (2×2″).
Rinse the part within 30 seconds: Immediately wash it off and don’t let it sit too long. This chemical can burn or etch the surface if left too long.
Method 3: Buffing
This method requires professional detailing tools. It is better to take your car to a professional auto detailer. A detailer uses a polishing machine and a stronger compound.
The good news is, you can avoid all this by keeping your car away from the rain or hosing it down as soon as you can. Regular waxing can also prevent acid marks.

