Why Can't Water Stains Exposed to Sunlight Be Wiped Off?

[CarterLee]

Black watermarks on white cars are mainly caused by calcium oxide carried in rainwater that settles on the vehicle, which can also commonly appear on glass. If the car is not washed for a long time after rain, the whitish substance is actually calcium oxide. For water stains, you can first try wiping them with a towel or sponge soaked in cleaning solution. If they cannot be wiped off, it indicates that the watermarks have penetrated the car paint, and the only solution then is polishing, which can be done using a polishing machine or clay bar. Below is relevant information about water stains: 1. Using Professional Cleaning Products: For water stains left on a car parked outside for a long time after rain, professional cleaning products can be used to remove them, such as water stain cleaners, cleaning wax, or clay bars. 2. Minimizing Polishing: However, it's important to note that while polishing can remove stubborn water stains, it is a consumptive maintenance process that reduces the thickness of the paint. Therefore, polishing should be done as infrequently as possible. If necessary, it is recommended to have polishing done at a professional auto detailing shop to avoid damaging the paint.