There might be the reasons of the semi-glossy state of the lacquer and the appearance of sanding marks on paint film:
1. The pre-coated primer on the surface of the porous substrate is not well sealed.
2. Improper primer spraying method.
3. Improper surface treatment of primer and improper polishing method.
4. Before the primer is completely hardened, the topcoat is sprayed, and the thickness of the topcoat is not enough.
Prevention method:
1. Correctly treat the primer surface.
2. The thickness of the primer layer should be appropriate, use the recommended thinner in proportion, and stir well before use.
3. Sand the surface after the primer is completely hardened. Use sandpaper of appropriate fineness. The surface of the primer should be flat and smooth after sanding.
4. Spray the topcoat of sufficient thickness, and each topcoat should be thin and wet.
Repair method:
After the paint film is completely hardened,smooth it and then polish it.
If the situation is serious, smooth the defective part and repaint it.
