How to Seal Chalky Exterior Paint
- 1). Scrub or power-wash as much chalk as possible from the siding. Rinse the siding thoroughly, and allow it to dry for at least two days.
- 2). Seal the chalky surface with a coat of alkyd or oil-based exterior primer. Choose primer suitable for the type of surface -- an alkyd primer designed for painting chalky exterior paint on redwood siding is not necessarily the best choice for aluminum siding.
- 3). Allow the primer to dry for between eight and 24 hours or as indicated by the product label. Drying time is affected by temperature and humidity, so it may take even longer in cool, damp conditions.
- 4). Paint the surface with two coats of 100 percent acrylic exterior paint.
