Blushing ("Haze")

Blushing ("Haze"): A milky grey cloud appears on the painted surface.

Harmaus_v2

 

 

 

 

 

Cause:

Blushing typically occurs when painting in humid conditions. The spray air and solvent evaporation lower the substrate temperature below the dew point, causing moisture to condense on or into the paint. The problem worsens if:

  1. A fast-evaporating or low-quality thinner is used.
  2. Drying is accelerated by blowing air, which increases solvent release.
  3. Heating and ventilation are insufficient.

Prevention:

  1. Use high-quality and appropriate thinner suitable for the painting conditions.
  2. Add the recommended amount of thinner when painting in humid conditions.
  3. Ensure proper spray gun settings and technique.
  4. Make sure the spray booth is well ventilated and the temperature is adequate.

Correction:

  1. If blushing appears during painting:
    1. Warm the affected area, or
    2. Add a retarder thinner and apply additional layers.
  2. If the paint has dried, minor blushing can be removed by polishing.
  3. In severe cases, the surface must be sanded and repainted.
     

Recommended products to prevent and correct possible issues:

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