During operation, these workers tend painting machines, observe gauges on the control panel, and randomly check articles for evidence of any variation from specifications. Although the majority of painting and coating machine operators are employed in manufacturing, the best known group of these workers refinish old and damaged cars, trucks, and buses in automotive body repair and paint shops. Automotive painters are among the most highly skilled manual spray operators because they perform intricate, detailed work and mix paints to match the original color, a task that is especially difficult if the color has faded. To prepare a vehicle for painting, automotive painters or their helpers use power sanders and sandpaper to remove the original paint or rust, and then fill small dents and scratches with body filler. They also remove or mask parts they do not want to paint, such as chrome trim, headlights, windows, and mirrors.
Automotive painters use a spray gun to apply several coats of paint.
They apply lacquer, enamel, or water-based primers to vehicles with metal bodies, and flexible primers to newer vehicles with plastic body parts. Controlling the spray gun by hand, they apply successive coats until the finish of the repaired sections of the vehicle matches that of the original undamaged portions. To speed drying between coats, they may place the freshly painted vehicle under heat lamps or in a special infrared oven. After each coat of primer dries, they sand the surface to remove any irregularities and to improve the adhesion of the next coat. Final sanding of the primers may be done by hand with a fine grade of sandpaper.