from Goss’ Garage by Pat Goss

As air quality continues to deteriorate, more and more cars are looking shabby and decrepit long before they should. Although automotive paints have improved enormously over the years their enemies have become much more aggressive. Most notable of those enemies is a process called acid rain. But although the name acid rain implies it falls from the sky that isn’t necessarily true. Actually, the majority of acid rain damage occurs from dust, water drops and sunlight.

As you drive, pollutants from the air, road and other cars are deposited on your car in the form of a very fine, nearly invisible dust. If your car is light colored you may not even notice the dust but for those of you who own dark colored cars it will make you nuts.

Road dust is actually a vicious, acidy mix of chemicals from exhaust, powdered tire rubber, oil drips and other nasty automotive byproducts. You can’t avoid it; every time you drive microscopic particles of this dust accumulate on your car. It remains there ready to ambush your paint until the car is washed. It’s this dust that kills untold thousands of paint jobs every year.

Once you have a coating of dust it only takes a little moisture and sunshine to set the acid rain phenomenon in motion. Unless your car lives exclusively indoors it will get wet, most commonly from dew that settles on the paint overnight. The dew sits there in those wonderful little beads that we all interpret to mean we have a good coat of wax on our cars. True but waxes that cause water to bead may actually lead to problems.

Okay, so you have beads of water sitting on your paint, so what? Well, remember back in grade school when you used a magnifying glass and sunlight to ignite paper? Remember how the magnifying glass concentrated sunlight so much that the paper it was focused on burst into flames? Uh oh! Guess what? Water droplets can act just like a magnifying glass etching, dulling and ultimately destroying paint.

Those friendly looking little drops of water we consider to be beneficial absorb some of the contaminated road dust. When this is followed by sunshine some droplets will magnify and concentrate the sunlight onto the paint beneath them. This causes intense heat under some of the drops which softens the paint and ultimately burns the acidy contamination from the water droplet into the paint. Déjà vu, science and chemistry class revisited acid rain without any rain!

Normally there will only be a few drops that focus the light in such a manner that it causes this during any given event. But considering dew forms nearly every night during spring, summer and fall, over time there will be thousands of spots which ultimately lead to dull, lifeless looking paint.

You can mostly prevent acid rain damage by keeping your car clean and parked out of direct sunlight when it’s damp. For the longest shiniest paint life get off your butt and get busy because a heavy, sacrificial coat of wax adds a protective barrier between the methyl-ethyl bad stuff and your car’s paint. The wax is sacrificed and takes the beating rather than your paint. Just another reason to practice good car keeping.