Cause:
Insufficient mixing of the paint.
Wrong type of thinner or poorly dissolving thinner.
Improper spray viscosity.
Uneven spray coat thickness and poor spraying technique.
Insufficient drying time.
Too thick or too wet spraying.
Incorrect application temperature.
Correction:
Spray additional layers of paint using the correct technique to cover the defects.
Sand and respray once the defective surface is completely dry.