Paint Finish Problems - Metallic Mottling
1. Metallic Mottling

Metallic particles in the base coat are dispersed unevenly, partially changing the color’s appearance.
Metallic particles are moved to irregular arrangement during clearcoat application.

CAUSES:
Improper painting conditions (paint reducer/thinner type, paint volume, air pressure, discharge volume, use of spray gun) and painting technique (spray pattern).
Paint reducer/thinner evaporation rate extremely slow.
Clearcoat excessively diluted with paint reducer/thinner.
Insufficient drying time between application of metallic color coat and clearcoat.

PREVENTION:
Paint under the optimum conditions.
Inspect and clean the spray gun.
Properly dilute clearcoat with the paint reducer/thinner.
Allow sufficient drying time before clearcoat application.
Apply clearcoat in several thin coats.

CORRECTIVE ACTIONS:
If the clearcoat has not been applied, take enough setting time to and repeat the metallic color coat application steps to remove unevenness.
If the clear coat had already been applied, dry the surface completely. Then sand and repaint.