chalking
CHALKING is evident with the formation of fine, white powder on the surface of the paint film due to weathering, which may give the appearance of colour fading.
POSSIBLE CAUSES:
- The use of a low-grade, highly pigmented paint
- The use of an interior paint for an outdoor application
- Over-exposure of a coating which does not have adequate UV resistance
- Painting of acrylic primers on walls with moisture contents of higher than 15%
- Over-thinning of a coating Over-spreading of the primer and/or the topcoat
SOLUTION:
- Scrape or sand the substrate to remove wrinkled coating.
- If using a primer, allow it to dry completely before applying a quality topcoat.
- The primer selection will depend on the type of surface to be primed
