In fact, the basic coating process of automobile sheet metal parts is widely used in the whole process of body sheet metal repair. According to the author's experience in automobile sheet metal repair for many years, the specific application of basic coating technology in the repair and replacement of body sheet metal parts can be classified into the following categories:
The ferrous metal sheet is easily oxidized and corroded gradually due to factors such as exposure to air or contamination of harmful substances, resulting in yellow rust spots and damage to the original coating layer. Especially in the parts processed by hammering, welding and other processes in the process of sheet metal work, it is more likely to damage the original coating protective layer and accelerate corrosion. Even if the paint film is sprayed, the paint film will quickly mix with The base coat comes off together. At this time, a thorough coating treatment must be carried out again.
Use a wire brush or iron sandpaper to polish and clean the surface of the ferrous metal sheet. Conditionally, you can use the widely used cleaning tool - nylon grinding disc to thoroughly polish and clean the metal surface. When dismantling and repairing the body (especially the accident car), the folded edges and lap joints of the sheet metal should be sprayed with a spray liquid specially used for rust removal, paint removal, and removal of oxidized slag and dirt before and after metal welding, or use A rust-proof primer with good rust resistance.
If the car body after repair of the auto parts is not treated with anti-corrosion, the cracks of the joint surface of the sheet metal parts will be oxidized and rusted due to the existence of various impurities and water vapor within one or two years, which will affect the strength of the welding point, so it should be timely. Spray solder zinc.
Welding zinc agent (zinc-rich coating) is a new material specially used for anti-oxidation and rust protection of the joint surface of sheet metal parts. It has good electrical conductivity, high temperature resistance, and electrochemical cathodic protection. It can form a rust-proof protective layer between the welding joint surfaces of sheet metal parts, improve the ability of the parts around the solder joints to not be rusted, protect the solder joints, and ensure The strength of the repaired body is not inferior to the original body.