Mould 11 Tannin Bleed

TANNIN BLEEDING

TANNIN BLEEDING

The brown or tan discoloration on a painted surface, most commonly observed over knots in certain types of timber (eg. Merbau, Western Red Cedar, Meranti).

POSSIBLE CAUSES

• The use of a coating with poor stain blocking properties. • Excess moisture in the substrate.

• Poor conditions during the application or drying period (eg. low temperatures, humid conditions, condensation, rain or dew).

SOLUTIONS

• Determine and eliminate the source of moisture and repaint with a stain blocking primer or top coat once the surface is clean and sound. • Ensure application and drying conditions conform to manufacturer’s recommendations.