2000 Saab 9-5 Owner's Manual - Page 211

Car care and technical information Stir both primer and touch-up enamel thoroughly before use and allow each coat to dry before applying the next. 211 Anticorrosion treatment The entire car is corrosion-protected at the factory in different stages by an electrolytic immersion coating and a polyester-based protective coating to protect against corrosion caused by stones flung up by the wheels. A thin penetrating anti-rust oil is also applied in cavities and body members. In addition to conventional anti-corrosion treatment like painting, underbody treatment and cavity treatment, most of the body panel surfaces are galvanized. These include the hood, the doors and the underbody. The anti-corrosion treatment on the underside of the car and inside the wheel arches is particularly exposed to constant wear and possible damage, the degree of which will obviously depend on driving conditions. What causes rust? Steel body panels of automobiles are subject to rusting whenever air and moisture manage to penetrate the protective finish, and body panels may rust through if the process is unchecked. Rusting can occur wherever water is trapped or where the car's panels are continuously damp. Damage to paint and undercoating by stones, gravel and minor accidents immediately exposes metal to air and moisture. Road salts used for de-icing will collect on the bottom of the car and promote rusting. Areas of the country with high humidity have great potential for rust problems, especially where salt is used on roads or there is moist sea air. Industrial pollution (fallout) may also damage paint and promote rusting. Two-coat enamel As the name implies, two-coat enamel is applied in two operations. The first coat, the base color, contains the pigment, metal flakes and binder. The second coat consists of a clear enamel, which provides the final gloss for the paintwork and protects the base from moisture and environmental contaminants. Touch-up stone-chip damage as follows: 1 Thoroughly clean the damaged area. 2 Apply the primer, base color and finally, the enamel. To achieve the best finish, apply two or three coats of primer.