Surfactant Leaching

Concentration of water-soluble ingredients on water-based paint, creating a blotchy, sometimes glossy appearance, often with a tan or brownish cast. More likely with tinted paints than with white or factory coloured paints.

Possible Cause

• Painting in cool, humid conditions or just before the occur. The longer drying time allows the paints water-soluble ingredients - which would normally evaporate - to rise to the surface before the paint thoroughly dries.
• Exposure to steam or condensation before adequate curing time can also lead to this issue.

Solution

Ensure the temperature in the room is above 10 degrees celcius while painting and during the curing time. Keep airflow during the drying phase with fan heaters and open windows. Do not expose paint to condensation for 48 hours after painting. If the problem occurs the water-soluble material can be washed off with a mild detergent and water but should be done as soon as it is noticed. Surfactant leaching should not affect the ultimate durability of the coating.

Images courtesy of the Paint Quality Institute from Dow Coating Materials