A: Hatbanding (also known as "picture framing") is typically caused by over-application of paint when cutting-in walls, corners, trim and ceiling areas with a brush or by rolling walls with a very thick roller cover. When beginning to paint, start where the ceiling meets the walls. Using a 2" to 2 1/2" trim brush, "cut in" by applying a 3"-wide strip of the coating along the perimeter of the wall/ceiling line, beginning at the corner of the room. Cut in one section at a time, and alternate between cutting-in and painting the ceiling. This maintains a wet edge on both the area being cut in and the rolled ceiling area, and prevents a visible line between the cut-in area and the rest of the ceiling.
Q: If my trim was last painted with an oil-based coating, can I repaint it with latex paint?
A: Yes, but proper preparation is a must. First, clean and sand the oil-based coat to promote adhesion. If you cannot sand, then you need to prime with an adhesion-promoting primer.
Q: Why is using a primer so important?
A: A properly selected primer creates better hide, seals the surface, creates adhesion, enables colour change, achieves the proper finish colour when tinted, resists corrosion, and promotes longer life of the total system.
Q: Must I sand previously painted woodwork/trim before I apply a new coat?
A: Yes, in order to promote proper adhesion, the old coating must be cleaned and sanded before recoating.
Q: What's the proper way to perform "touch-up"painting?
A: In general, touch-up painting should be done under conditions that are as close as possible to those present when the job was originally done, and ideally, with paint left over from the original job. Also, always apply the material with the same kind of applicator as originally used. Never use a brush to touch-up an area that was previously painted with a roller, as the contrasting textures will make the touched-up areas quite noticeable.
CAUSE: A common cause of peeling on surfaces composed of mortar, brick, building block or concrete is efflorescence, where soluble salts are present. When dissolved by water, they are carried to the surface and remain after the water has evaporated. These salts can push paint away from the surface and peeling results. Efflorescence occurs on brick walls of new construction. A common building practice is to treat new brick or concrete with meiotic acid, rinsing with water to clean away excess mortar. Rinsing removes only those salts on or near the surface. After painting, salts remaining within the bricks will absorb the moisture and travel to the surface, causing peeling. Peeling can also occur when alkyd or oil paint is applied over unetched concrete. Alkyd resins that come in contact with an alkaline surface form a soap film between the concrete surface and the coating, called saponification. This will cause softness and loss of adhesion of the alkyd coating.
SOLUTION: If efflorescence is evident, it must be removed before repainting. First, remove all flaking or chalking paint from the damaged area by wire brushing or sandblasting. If necessary, try applying a solution of 5% meiotic acid or undiluted vinegar. Rinse with clean water. Fill all cracks with masonry patching compound, latex concrete patch, or caulking compound. If the surface is very porous, apply an alkali-resistant primer or block filler. Cover with latex house paint. To prevent recurrence of efflorescence on interior walls, the exterior walls should be sealed.
NOTE: Extraneous water sources must be removed before painting (e.g., migration at ground level, often caused by poor drainage).
