How to solve the poor cover and bottom defects of the film?

Poor bottom cover

Due to thin spraying, insufficient film thickness or poor hiding power of the paint, the phenomenon that the background color can be seen is called poor bottom covering.

outcropping

Due to missed spraying, the part of the coating is not sprayed, which is called exposed bottom (commonly known as lack of paint).

too thin

The film thickness (instrument: paint Film Thickness Gauge) is insufficient, the film thickness does not reach the film thickness specified by the process, the background color can be seen, and the paint film that makes the painted surface rough is called too thin. It includes the defect of "thin electrophoretic coating film"!.

1. Etiology

1) The paint is not fully stirred before use, or the covering power of the paint used is poor.

2) Excessive dilution or improper selection of diluent, the construction viscosity (or construction solid content) of the coating is low.

3) Use an excessive amount of slow-drying thinner to make the paint form a vertical flow before reaching a sufficient film thickness.

4) Spraying is too thin, or the number of sprayed layers is too small.

5) If the spraying is not careful or the shape of the object to be coated is complex, the phenomenon of missing coating occurs.

6) The color difference between the primer and top paint is too large, such as painting a light-colored paint with high brightness on a dark-colored paint surface.

2. Prevention

1) The paint should be fully stirred before use, and a qualified thinner should be selected to properly increase the construction viscosity (or construction solid content) of the paint.

2) Spray the correct number of layers to achieve the desired film thickness.

3) Improve the proficiency of spraying operation and operate with caution.

4) Use a topcoat with strong hiding power.

5) The color and gray scale of the base coat should be as close as possible to the color of the paint. Especially when using pearlescent paint, spray the primer with a similar color first , which can save the amount of pearlescent paint and reduce the cost. Because of the low hiding power of pearlescent paint, the price is high.

3. Remedy

Allow the paint to dry slightly before respraying, or allow it to dry completely, then wet sand it level before respraying.