What are common paint defects and their causes?

Common paint defects: Runs/sags (excessive film build, improper viscosity), orange peel (poor atomization or flash time), fisheyes (contamination, silicone), craters (surface contamination), dirt/inclusions (airborne particles, booth cleanliness), color mismatch (pigment variation, application differences), metallic mottling (improper basecoat application), poor adhesion (contamination, insufficient pretreatment), solvent pop (trapped solvent during baking), and water spots (moisture during flash). Investigation considers material properties, application parameters, environmental conditions, and substrate preparation. Statistical tracking identifies trends, and root cause analysis drives corrective action through design of experiments.