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Chalking: Formation of fine powder on the surface of
the paint film during weathering, which can cause color
fading. Although some degree of chalking is a normal,
desirable way for a paint film to wear, excessive film
erosion can result in heavy chalking.
Possible Causes:
Use of a low-grade, highly pigmented paint.
Use of an interior paint for an outdoor application.
Solution:
First, remove as much of the chalk residue as possible,
using a stiff bristle brush (or wire brush on masonry) and
then rinse thoroughly with a garden hose; or use power
washing equipment. Check for any remaining chalk by
running a hand over the surface after it dries. If
noticeable chalk is still present, apply a quality
oil-based or acrylic latex primer (or comparable sealer
for masonry), then repaint with a quality exterior
coating; if little or no chalk remains and the old paint
is sound, no priming is necessary. |