The air in the   coating environment is not clean, such as dust, paint mist, etc. Silicones or   waxes are used around the coating environment.

Control the   cleanliness of the construction environment.

The coating   environment temperature is too low and the humidity is too high.

Control the   temperature and humidity of the painting environment.

Paint mixing tools   as well as equipment，the painting tools, work clothes and gloves are not clean.

Ensure the   cleanliness of coating equipment and tools and the quality of compressed air.

The substrate is   poorly degreasing, and foreign matter such as water, oil, glue of the masking   tape, dust, soap, sanding dust, etc. adhere to it.

Strengthen the   surface treatment of the coated object to prevent the paint film from being   defective due to foreign objects.

The old coating   film is not polished completely, and there are defects such as pinholes and   depressions.

Carefully   polish, choose the appropriate sandpaper model and polishing method to   eliminate the influence of the old film.

The coating film is too thick.

Reduce the oil   output of the spray gun to speed up the spraying speed and reduce the number   of spraying.