Danos por corrosão/reparo de corrosão

501-25-38 Body Repairs - General Information 501-25-38 DESCRIPTION AND OPERATION Corrosion Damage/Corrosion Repair Modern vehicle bodies are protected from corrosion by elaborate measures. Multilayer coatings on the panel surface prevent direct contact between the metal and oxygen, and so protect it from corrosion. In the long-term however, corrosion on a vehicle cannot be completely prevented. NOTE: Basic and in-depth training is offered on the following topics. You will find an overview of the complete range of training in the Training Brochure issued by the Ford Service Organization. What is corrosion? Corrosion is destruction of a subsurface caused by chemical or electrochemical effects which operate from the outer surface. If the protective layers become damaged, electrochemical conversion processes are initiated, which allow the metal to oxidize. This leads to the formation of corrosion. The following factors lead to corrosion: ‡ Mechanical damage such as stone chips and scratches which penetrate through to the steel panel. ‡ Damp interiors. ‡ Unfavorable weather or environmental conditions, as may occur in areas with high humidity, high salt content in the air or serious air pollution due to aggressive gases and dusts. ‡ Insufficient corrosion protection after repairs. ‡ Lack of care by the vehicle owner of the painted and corrosion proofed surfaces or areas on the vehicle. In order to maintain long-term corrosion protection, the vehicle must be checked at regular intervals. In doing so, the follow areas must be inspected and any damage rectified: ‡ Damage to the paint surface cause by scratches or stone impact must be suitably rectified according to the specifications. ‡ Damage to the PVC underbody protection or the PU stone chip protection must be refinished. ‡ Damage to the PVC underbody protection or the PU stone chip protection must be refinished. ‡ Incomplete or damaged sealing at clinched flanges must be renewed. ‡ Check the cavity protection and renew it if incomplete. ‡ Poorly installed or damaged covers and stone chip protection fixtures must always be renewed. ‡ Check seals and seal carriers for wear and correct mounting. Any damaged seals must be renewed. ‡ All rubber grommets and blanking plugs must be present and correctly installed. ‡ A damp or wet floor inside the vehicle indicates that there are leaks in the bodywork. The interior must be dried out and the leaks must be completely rectified. The corrosion formation can vary in extent. With rust film or edge rust formation, the surface of the paint has small traces of corrosion present. The traces of corrosion can possibly be removed in such cases by polishing the paint surfaces. If this is not possible however, the traces of corrosion must be rectified by using a touch-up technique. If the corrosion is just starting, with up to 1 mm rusting below (in the form of a dot or a line) the damage is rectified as follows: ‡ Clean the defective location. ‡ Mechanically remove the rusting which is starting below the surface. ‡ If the area is small, apply primer and allow it to dry, then use the paint pencil to touch up the area - if not, respray the damaged area. If rust is already under the paint finish to the steel panel, then the whole paint finish in the affected area must be sanded away. Furthermore, the existing traces of corrosion in the body panel must be carefully and completely removed. Finally a new paint finish must be applied in this area. In the case of rusting through, the affected body panel is already completely destroyed. Such damage requires complete or at least partial replacement. NOTE: : In the general section there are several chapters which present the techniques necessary for a professional corrosion repair. The outcome of this is the following repair sequence: ‡ Remove the rusted-through part. ‡ Remove the remaining traces of corrosion. ‡ Offer up the new part. ‡ Prepare the joint areas.