Painting Defects

Blistering

This defect is the appearance of irregular blisters on the paint finish.

This defect can be caused by:

• Not correctly cleaning substrate
• Contamination of the brush, air gun, line etc.
• Using wrong thinner or incorrect amount of thinners
• Old paint surface
• Excess film thickness
• In timber finishes, not allowing the solvent, particularly paint removers , to evaporate before repainting

This defect may be overcome by:

• Cleaning all surfaces free of grease and allowing the solvent to evaporate.
• Using recommended thinner at correct ratio.
• In spray applications, inspect so that water does not build up in the traps, especially in humid weather.
• Check that the new paint is compatible with the old surface.
• Do not apply paint films too quickly and allow solvents to evaporate before re-coating.

Blooming

This defect gives a bloom or white deposit, like the bloom on a grape or plum, after the paint has dried. The cause is the rising of soluble fractions of the pigment rising to the surface on the paint's drying. The remedy for spray paints is to rub the surface down.

Blushing

This is a white deposit appearing on the surface of lacquer films only. The defect is caused by painting with lacquers in high humidity conditions where the water contained in the air condenses on the paint film The remedy is not to paint in humid conditions or to add a strong, active solvent that may stop the blushing.

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