In metallic finishes, clouding appears as uneven dark and light patches/shadows.

Causes

1. The base-coat was applied unevenly – too thick or too light.

2. The flash-off time between base-coats was too short, or the base-coat was not fully flashed before applying the clear-coat. This causes the metallic coat to re-dissolve, and the metallic and pigment particles float and change their positions.

3. The first application of the clear-coat was too wet, causing the base-coat to re-dissolve.

Prevention

Spray the metallic base-coat evenly and not too wet. Ensure there is enough flash-off time between coats or before applying the clear-coat, and follow the manufacturer’s instructions.

Repair

If clouding is visible before the clear-coat application, re-spray with appropriately thinned base-coat and reduce the spray gun pressure (do not apply too thick or too thin).
If clouding is visible only after the clear-coat application, sand the dry clear-coat and re-coat with base-coat and clear-coat.