Why does the painted surface have multiple cracks resembling dried mud

Irregular deep cracks found on the dried paint film resembles as mud cracks.

What are the possible causes?

• Paint applied too thick.
• To cover poor hiding, building up thickness of paint.
• Adhesion of the coating is insufficient to bear the stress.

How can I fix the problem?

• Remove the paint by scrap.
• Sanding the surface to smooth before repainting.
• Use correct paint system recommended paint manufacturer.