PAINTING FOR NEW VEHICLES 1-25 2. PAINTING PROCESS FOR NEW VEHICLES Passenger car body painting requires far more complicated painting than other ordinary paintworks because highly corrosion preventive performance and extremely high cosmetic quality are required of passenger cars. The painting process for them basically consists of chemical pretreatment and under- coat whose major purpose is rust prevention, and second and top coats that are designed mainly for giv- ing cosmetic quality to the surface. This type of painting is called a three-coat process. A larger number of second and top coats are often used (6-coat, 7 -coat, etc.) with luxury cars.
The actual painting pro- cess is more complicated because many other jobs are also done to the vehicle's body simultaneously. Shown below is an example of a painting process for passenger cars.
From bodywork II line To assembly line Chemical pretreatment stage Special painting stage Hot bath, degreasing Chemical pretreatment Rinsing Drying (Stripe painting, rocker black coating} D Dipping ~~ Drip dry H Washing H Drying I Painting H Drying Undercoating (ED} stage Black-out painting stage D Masking H Painting Masking H Varnishing H Painting H Drying I Undercoating stage Top coating stage D Body sealing stage Wet sanding stage I \l'let sanding H Rinsing H Air-biowing H Drying I Asphalt sheet placement Second coat stage Varnishing Anti-chipping coating Second coat and inner panel coating Black coating -27-