Paint cars without scraping putty, but some cars have many scratches and small dents. It needs to be polished once, scraped twice, and the red ash should be replenished twice after polishing. In some places, if you want to finish grinding, you need to spray primer. It will be more convenient to scrape putty. When scraping putty, the pit can be filled in several times, first and then gradually. The first grinding must be done horizontally with the coarsest sandpaper, and more water is needed. This is usually flat.