Painting in automotive sheet metal: Painting in automotive sheet metal is usually divided into three steps.

1) Primer: it fills sand marks and micropores at the bottom of the workpiece, increases the adhesion of the lower coating, and has the function of defect indication. -

2) Primer: Prepare a well-lubricated working surface for the topcoat, complete the last procedure of all primer work, increase the adhesion of the participating layers and have a certain isolation effect to ensure the quality of the topcoat.

3) Topcoat: Topcoat can be divided into single-layer paint and multi-layer paint, which are color fixing layer and decorative maintenance layer.

Surface treatment of sheet metal and painting: the surface treatment of painting is the last process of topcoat. When the paint surface is dry and solid, the above defects will be dealt with. If we try our best, it will flow to a center where the department is not satisfied. As long as it is made up later, it is called mirror treatment. First, use 1200-2000 mesh beauty sandpaper (2500 mesh if necessary) to stop leveling and polishing, then use coarse wax composed of pumice or clay to stop polishing and cutting, and dispose of traces of sandpaper.

Next, stop polishing with fine wax (without silicon), remove the traces of coarse wax, then treat with repairing agent to achieve perfect luster, and then completely remove halos and scratches with mirror treatment agent. Sheet metal painting is a multi-process maintenance project with high technical requirements.