Painting in the automotive industry is big business. Vehicles are painted primarily to provide corrosion protection and to enhance eye appeal of the product. It is estimated that approximately 50 million gal of paint are used annually to produce the cars and trucks in the United States.
The basic processes in painting automotive sheet metal and bodies are metal finishing, cleaning and phosphate coating, primer or undercoat application, baking or curing, wet sanding, color or topcoat application, and final bake. With some modifications, this is essentially the processing used in the entire automotive industry. In the steps of paint processing just mentioned, each may be a source of some type of pollution, either air or water.
Various types of air and water pollution and the relationship to each processing step are examined.