Causes of coating sandpaper marks defects in spray gun spraying and methods t...

Causes of coating sandpaper marks defects in spray gun spraying and methods to solve and prevent them!

Generally, before spraying the material, we will give the plate a simple surface treatment, such as grinding the substrate, etc., but there will be some unnoticed places in these processes, so it will bring some problems to our spraying. Then we need to solve these problems from the three aspects of causes, preventive measures and repair methods to better spray.

Problem: During drying, the surface shows signs of sanding or other treatment of the primer surface due to shrinkage of the paint film.

1. Causes

1. Improper surface treatment of the base coat, too coarse sandpaper, uneven grinding, insufficient filling, etc.

2. The topcoat was sprayed before the basecoat was sufficiently hardened.

3. The thickness of the paint film is not enough, or the drying speed is too slow.

4. The paint is not fully mixed, the type of thinner used is incorrect or the quality is too poor.

2. Preventive measures

1. Use sandpaper with appropriate fineness, fill in the deeper sandpaper marks on the surface with filler dust, and smooth the surface.

2. The thickness of the paint film should be appropriate, and the drying conditions should be correct.

3. Wait until the base coat is completely hardened before spraying the top coat.

4. Use only the thinner recommended by the manufacturer to mix the paint thoroughly.