Wash and dry the whole car. 2. Find out the oil pollution defects of the whole car body, such as pits, dents, wavy lines, peeling, paint peeling, rusty parts, etc. 3. The pits need to be repaired and reshaped by the maintenance machine. If there are corners, lines, arcs, etc., repair, restore and treat them. Paint can be used before construction. 4. It is required to remove the sheltered place during sheet metal construction before construction. 5. Stick the plastic parts on the car body with paper tape. Such as headlights, nets, decorative strips, glass, etc. 6. Use 60# paper or 40# dry grinding paper with grinding head on the dry grinding machine to grind the defective parts into burrs. 7. Clean all return trips with a blow gun or wet towel. 8. Scrape the sheet metal tool with a scraper for the first time, and don't scrape it too thick every time. Note: Just scrape off the exposed iron sheet, and all the exposed iron sheet must be covered. 9. Blow putty, and the putty must be smooth every time. Don't shave too thick every time. After shaving, bake it with infrared baking lamp, not too tightly and keep a certain distance. After drying, it can be polished with water mill and dry mill. Terrazzo is polished with 60# water sandpaper and special polishing pad. Dry grinding is to grind with 40# sandpaper on the dry grinding head at a uniform speed. When polishing, you must use your hands, straighten your hands, and repeatedly feel whether there is any depression. If there is, snort carries out secondary crawling. 10. Before scraping for the second time, clean the water and dust on the body surface. The second scraping method is as above. 1 1. It is very strict and picky when polishing putty. Close cooperation between eyes and hands can achieve the ideal effect. 12. After all defects in the car body are repaired with putty, the car body should be strictly inspected until it is completely consistent with the original car body, and then the primer can be sprayed. If any place does not meet the requirements, the primer can not be constructed, and the primer construction can only be carried out after it meets the requirements.