Q: What kind of paint and paintbrush should I use when painting moldings, doors, etc., so there are no visible brush marks?
-- Margaret Velasco, Dearborn Heights, Michigan
For best results with any painting project, it is imperative that you use a good-quality paintbrush. Although it may cost a bit more, the results will be more than worth it. A high-quality brush will have more filaments, which will be more securely anchored into the handle than a cheaper brush, and the filaments themselves will be of various sizes, with well-trimmed ends. These factors will help to ensure that the paint is applied smoothly. Also, be sure to use the right kind of brush for the kind of paint you are using: A latex paint goes on better with a synthetic brush, while an oil-based paint is better applied with a natural-bristled brush. If you use a natural-bristle brush with latex, you will find that the brush absorbs too much paint and swells, making it difficult to paint neatly.
You may need more than one brush for a project. A paneled door, for example, would require a smaller brush for moldings and panels, and a larger one for the rest of the door. Don't apply too much paint in any one area, and always make your final strokes with the very end of the brush, since the tips of the filaments are finer and will leave less noticeable markings. Try to work quickly and finish at the edge of the door, molding, wall, etc., so the paint doesn't dry and leave noticeable start and stop points. If your brush begins to drag at any point, your paint probably needs to be diluted a bit with a paint conditioner (try Floetrol for water-based paints or Penotrol for oil-based varieties).
Q: How can I tell if the paint on my walls is oil-based or latex? I cannot paint over oil paint with latex, right?
-- Anna Robinson, Oak Ridge, Tennessee
To determine whether the paint on your wall is oil-based or latex, all you need to do is rub a small area with a bit of denatured alcohol: Latex paint will come off; oil-based paint will not.
You can paint over oil-based paint with latex, as long as you prepare the wall first so the new paint will adhere. An acrylic latex primer (Benjamin Moore makes one called Fresh Start) will do the job. The other alternative is to sand the wall down first, but this is not the best solution because it can be messy, and if the walls were painted before 1970 the old paint may contain lead, which is dangerous to inhale.