PROBLEM: Uneven Gloss
CAUSE: Surfaces with varying porosity may, after painting appear nonuniform in sheen. This problem is sometimes referred to as "flashing". Uneven application can result in varying film thickness that may cause uneven gloss. Fog-strike or moisture on the paint film during drying can locally also affect gloss. Uneven gloss may also be caused by an unsealed porous surface. In this case, a primer-sealer is necessary to prepare the surface. Areas surrounding nail heads and wall studs tend to retain gloss because metal conducts heat and speeds up drying time. In addition, painting over a paint film that is not thoroughly dry or that is too soft can cause uneven gloss.
SOLUTION: If the surface is extremely porous, a prime coat is necessary. Otherwise, another finish coat, spread uniformly, should correct the problem. Some unevenness can be expected on rough surfaces, but additional coats tend to give better uniformity. If moisture contact has caused flatting or if temperature variation has occurred, apply another coat of paint when moisture is not present and/or when changes in temperature are less likely. If the undercoat was not dry, allow the flatted paint to dry hard and apply another finish coat.
PROBLEM: Poor Hiding of Colors
CAUSE: Possible causes of poor hiding include over-extended spreading, a radical color change, uneven application, excessive thinning, or inadequate mixing of paint. Certain colors such as yellow, red, and orange tones inherently offer weaker hiding.
SOLUTION: Most paints are designed to be applied as resolved. Thinning, if necessary, should be at a minimum. An additional coat of the same material and color, applied with a good quality tool at the recommended spreading rate, will usually provide good hiding. The exceptions are extreme color changes, extremely porous surfaces, and certain deep, clear colors. These require a prime coat tinted to the approximate color of the finish coat. Benjamin Moore color chips and color cards use a triangle symbol to identify deep, clear colors in the MoorO-Matic III system that require a tinted deep base primer to obtain good hiding. If you have any questions about the type and size of applicators and tools, just ask us!
PROBLEM: Peeling from Plaster Walls
CAUSE: Paint peeling from plaster could be the result of chalking of the surface. This chalking can be caused by alkali, moisture, or insufficient wet troweling of the white coat. Another reason for peeling is the presence of a glue size (from removed wallpaper), which absorbs water, underneath the paint.
SOLUTION: New plaster should be primed AFTER 30 days curing. This will allow for reduction in moisture and alkali content. After curing and before priming, the plaster should be wiped with a damp cloth to remove powder and dust. Peeling areas should be scraped down to a sound surface. Smooth the scraped edges with sandpaper. If peeling is severe, then all the paint should be removed. Otherwise the remaining coating will peel, thus causing the new coat to fail. Cracks and holes in plaster should be repaired before repainting. if patching is necessary, a water-mix patch should be used when the intended topcoat is latex. Oil based patching compounds sometimes bleed into latex. When using a water-mix patch, thoroughly dampen the surrounding edges of the damaged areas to prevent the plaster from absorbing moisture and becoming crumbly. If the surface is badly disintegrated, mount canvas or "hardboard" over the plaster. Apply primer before and after filling cracks and holes. Sand when dry.
PROBLEM: Picture Framing on Drywall (aka Hatbanding)
CAUSE: Hatbanding is caused by excessive cutting-in of the walls, corners, trim and ceiling areas with a brush or by rolling walls with an excessively long nap roller cover, thereby producing a heavy textured application when compared to brush applied cut-in areas. It may also be caused when applying a wet finish coat onto areas that are already dry.
SOLUTION: Feather-edge brushing of the finish coat when cutting-in of the areas to be painted produces a coat of paint that is approximately the same thickness as the coat applied later with a roller. The brush should leave a thin, feathered edge of paint that will merge into a smooth layer of new paint. By doing this, problems of the finish coat (i.e., hatbanding) are reduced. When rolling on smooth surfaces (i.e., drywall), use roller covers ranging from 1/4" to 1/2" nap, depending on the sheen of the finish coat to be applied. When rolling into surfaces that have been previously cut-in with a brush, turn roller sideways (rotate 90 degrees on the wall) and apply a thin coat of finish, rolling into the previously cut-in areas. Make sure to roll the finished coat back into the drying paint. Properly primed drywall reduces the occurrence of hatbanding.
