BLOCKING

Undesirable sticking together of two painted surfaces when pressed together (e.g., a door sticking to the jamb).

POSSIBLE CAUSES:

• Not allowing sufficient dry time for the coating before closing doors or windows.
• Use of low quality semigloss or gloss paints.

SOLUTION:

• Use top quality semigloss or gloss acrylic latex paint. Low quality latex paints can have poor block resistance, especially in warm, damp conditions.
• Follow paint label instructions regarding dry times.
• Acrylic latex paints generally have better early block resistance then vinyl latex paints or alkyd or oil-based paints; however, alkyds develop superior block resistance over time.
• Application of talcum powder can relieve persistent blocking.

Note: Images & information provided by The Rohm & Hass Paint Quality Institute.