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.

Intermediate primer: prepare a well-lubricated working surface for the top coat, 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 top coat is not chaotic.

Top coat: Top coat is divided into single-layer paint and multi-layer paint, which is a color fixing layer and a decorative maintenance layer.

Four. Surface treatment of sheet metal and painting: the surface treatment of painting is the last process of topcoat. After the paint surface is dried and cured, the defects on it will be treated with mirror surface. 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.

Stop grinding with fine wax, remove the traces of coarse wax, then treat with repairing agent to achieve complete luster, and then completely remove halos and scratches with mirror treatment agent.