Home Building Articles
October 27, 2009
By following some basic guidelines for surface preparation, primer application,
and topcoat application, it's possible to avoid the majority of the headaches associated
with interior paint.
Wall and ceiling surfaces should be completely dry before primer or paint is applied.
Use a damp cloth to remove loose dust and dirt created during the drywall installation.
If the drywall surface is wet, dusty, or dirty, the paint may not coalesce, bond,
and flatten as well as it should.
Make sure the ambient temperature isn't too low for painting. Cold temperatures
interfere with paint's ability to coalesce and bond; when it's too cold, the polymer
particles don't have sufficient energy to move together. The air, the surface, and
the paint should all be at the manufacturer's recommended temperature, which is
usually 40?F and rising. Also, confirm that the temperature won't drop below recommended
levels after painting for the time frame specified by the manufacturer.
Primer is the first coat of paint applied to the surface. Primer functions as an
intermediary between the drywall and the topcoat. A good primer seals the drywall
to provide a more uniform surface for painting. Primer also helps prevent brush
and roller marks in the topcoat. When primer is used, the topcoat is applied not
to the drywall surface but to the primer. Think of primer as the foundation for
a smooth, attractive interior paint job.
When priming drywall, the goal is to create a surface with uniform suction (absorption).
The areas where joint compound has been applied don't absorb primer as quickly as
the other paper-covered drywall surfaces. The result is a flatter finish in paper
areas than in areas of joint compound. To solve this problem, primer has a lower
solid content, which makes it less sensitive to the varying suction rates of different
surfaces. In primer, the polymer particles coalesce and bond more easily than they
do in paint, regardless of the surface to which they're applied. It's helpful to
understand that drywall primer doesn't hide flaws, and it isn't nearly as durable
as paint. Its function is to create an even surface for paint. It levels out suction
rates across the drywall surface.
The topcoat is the last coat of paint applied to the surface. Stir the paint before
applying the topcoat. You mayneed to run the paint through a filter to remove dust
and dirt from site work. Apply the manufacturer's recommended thickness of wet topcoat,
backroll the paint, and measure the mil thickness in order to ensure the correct
dry paint thickness. Backrolling can enhance the uniformity of the paint coating.
Depending on the paint system selected, applying two lighter topcoats can provide
a higher quality and more durable finish than applying one heavy topcoat, which