Interior Paint Solution Center

Lapping

• Failure to maintain a "wet edge" when painting.
• Use of a low solids "economy" paint.
• Lack of a primer over a porous surface.

• During application, maintain a wet edge by applying the coating starting from the unpainted area and going back into the just-painted surface.  This technique (brushing or rolling from "dry to wet", rather than vice versa) will produce a uniform appearance.  It is also wise to work in manageable-size areas; plan for job interruptions at a natural break, such as a window, door or corner.  Using a top quality interior latex paint makes it easier to avoid lapping problems because they are formulated with the optimal amount of solids (pigments and binder).  If substrate is very porous, a primer/sealer will provide an optimal surface that will prevent the topcoat from drying too quickly and reducing wet edge time.  Alkyd paints can also be used, with a primer, as they generally have superior wet edge properties.

Mildew

• Mildew forms most often on areas that tend to be damp, or receive little or no direct sunlight (e.g., bathrooms, kitchens, and laundry rooms).
• Painting over a substrate or coating on which mildew had not been completely removed.
• Use of a low quality latex paint.

• Test for mildew by applying a few drops of household bleach to the affected area; if the suspected mildew turns lighter in color or is bleach away, the discoloring is probably mildew.  Remove all mildew from the surface by scrubbing with a diluted household bleach solution (one part bleach, three parts water), while wearing rubber gloves and eye protection.  Rinse thoroughly.  To protect against future mildew growth, use a top quality semi-gloss or high gloss latex paint.  Clean regularly with common household cleaners that contain bleach.  Take steps to remove excessive amounts of moisture from the area, i.e. dehumidifier.  For high moisture areas such as bathrooms, consider installing an exhaust fan leading to the outside of the home.

Mud Cracking

• Paint is applied too heavily, usually over a porous surface.
• Paint is applied too thick, in an effort to improve the inherent poor hiding (coverage) of a low quality paint.
• Paint is allowed to build up in corners upon application.
• Paint is subjected to low humidity and flash drying conditions.

• Remove affected coating by scraping and sanding the surface smooth.  Prime if necessary, with a primer-undercoater.  A primer-undercoater will reduce the porosity of the substrate providing better enamel holdout.  A sealed surface allows the vehicle resins in the topcoat to remain on the surface and form a stronger film.  Repaint using a high quality interior latex paint applied at the proper mil thickness.  Quality paints have very good application and hiding properties, which minimize the tendency to apply too think a coat of paint.  Avoid painting in conditions where low humidity or high heat can cause flash drying.

Picture Framing

• Usually related to hiding and coverage properties.  Applications by brush will generally result in lower spread rates than rolling.  The difference in the dry film thickness and the resulting degree of hiding from the different application methods can produce color or sheen differences.
• Adding colorant to a non-tintable paint or using the wrong type or level of colorant.

• Make sure that coverage rates with brush, roller, and spray application are similar.  Don't cut in the entire room before roller coating.  Work in smaller sections of the room to maintain a "wet edge".  With tinted paints, be sure the correct colorant-base combinations are used.  Factory colors, as well as in-store tints, should be thoroughly shaken at time of sale.

Poor Flow / Leveling

• Use of low quality paint.
• Application of paint to "touch up" a partially dried painted area.
• Re-brushing or re-rolling a partially dried painted area.
• Use of the wrong type of nap size roller cover or poor quality brush.

• Paint with a top quality latex paint that is formulated to provide optimal paint flow and leveling.  With a high quality coating, brush and roller marks will "flow out" to form a smooth, uniform film.  When using a roller, be sure to use a roller cover with the recommended nap size for the type of paint being used.  Use of a high quality brush is also important.  Their bristles and blended, shaped, and cut to product optimal paint distribution to the surface resulting in the proper flow and leveling of the paint.

Poor Hiding

• Use of a low quality paint.
• Use of low quality tools / wrong size roller nap.
• Poor flow and leveling (see Poor Flow / Leveling)
• Use of a paint that is much lighter in color than the substrate, or that primarily contains low-hiding organic pigments.
• Not using a primer.
• Application of paint at a higher spread rate than recommended.

• If the color of the substrate is significantly different, it should be primed with a tinted primer / sealer before applying a topcoat.  When applying a coating containing a low-hiding organic color, i.e. Candy Apple Red, apply a deep tint primer first to provide necessary hide support.  Use quality tools; use the recommended roller nap size.  Follow manufacturer's recommendation on the coating's spread rate.