Acid Rain
by Paul Gasparola and Angela Brown
Professional Detailers Association


What is acid rain, water spots and what is the difference between them? Both can occur on your car's paint finish from a little dew, rainfall or mist from sprinklers. The difference between the two is the damage each create and the difficulty to remove to sometimes impossible.

Water spotting is the less of the two evils here. Water spots leave a film of the droplet area, which had contained salts and rust chemicals when the water dried. Thus after drying, the chemicals etch the paint, leaving an irregular ring on the paint surface. To remove these, you must first wash (use car soap) and dry the vehicle, then follow with a premium polish and wax. For the harder spots use a small amount of white vinegar on a cloth wipe then wipe the area (small section at a time). Following again wash, dry and polish and wax. If you follow the above steps and the spots do not come out or they are not removed, then you may want to consult a professional detailer. Most likely they are not water spots, but acid rain damage.

Acid rain has been blamed for killing lakes and trees, it has found another target, paint on cars. Acid rain is largely created from emissions sulfur dioxide and nitrogen dioxide are discharged from factories, fossil fuel burning power plants and the internal combustion engines and are altered in the atmosphere. Here the compounds turn into sulfuric acid and nitric acid, which then can travel hundreds of miles before they fall to earth as rain, snow or dust particles. When mixed with a little dew, rain, snow or water mist from yard sprinklers you now have a mixture of Sulfuric acid on your car's paint finish. If left on the surface the moisture evaporates and the acid remains. Concentrated by sunlight, the sulfuric acid can became so strong that it will "eat" (etch) through a car's finish. Typical acid rain damage may first look like water droplets (spots, here you must know the difference). Once the damage occurs, it cannot be removed, repaired by just washing. And it is particularly mot correctable on vehicles that have dark or metallic finishes. In some cases, damages appear as a white or black ring with a dull center. Severe cases shows pitting and can etch to the bare metal.

"In the United States, the acid rain problem for cars appears most severe in the northeast and southeast, although problems have been reported elsewhere," said Mr. Gallagher, a DuPont official. "It varies in severity depending on time of year, weather and location," he said. "One day you could have a problem, one year you could have a problem and other times you won't."

Minor acid rain damage can be repaired. First rinse the vehicle and apply a diluted solution of the paint-safe alkaline solution. Let it soak for five minutes. This neutralization the residual acid is critical. If the acid residue is not neutralized, acid damage can reoccur when the surface gets wet again. Second once the surface is neutralized, rinse and dry the vehicle. Then use an intermediate polish to buff the surface smooth. It is best to use a polish compound that is very well lubricated (oily) so that while you are buffing, you won't burn the paint (by hand or machine). Follow this with a premium wax with "acid rain protectors added". If the acid rain damage is too severe, the only recourse is to have the vehicle repainted.

Now we know what water spots and acid rain can do, how to tell the difference and the corrective action. How can you keep from getting water spots and acid rain? First, you want to keep your car waxed often and on a regular time frame. If the vehicle spend a lot of time outside and not garaged, you may want to wax more often. In a high acid rain area of the country - Every 2-3 months is something you should at. But if the car is garaged and does see rain ...3-4 months minimum.

Paint finishes (also clear-coats), are susceptible to damage from factors, as diverse as industrial discharges and bird droppings. But in the case of acid rain damage, most car industry experts say the best defense is a simple one, try to wash the car after it rains and keep the vehicle waxed often with a premium product.

2000 Paul Gasparola and Angela Brown (Member Profession Concourse Detailers Association)