If you'd like to stain a wood surface that has already been painted, accomplish your goal by applying a solid stain. Unlike semitransparent stains, which are absorbed into bare wood and enhance its natural appearance, solid stains add a rich colorful film that sits atop the wood's surface. Because latex paint is water-based, it is incompatible with oil-based solid stains. To generate a durable finish, you must apply a special primer that will bond to both coatings.
Things You'll Need
Professional painter's tape
Canvas drop cloth
2 to 4-inch natural-bristled paintbrush
Wipe the latex finish with a rag dampened with mineral spirits. Let the latex dry for one hour.
Cover surfaces adjacent to and below the latex finish, using tape and drop cloths.
Coat the latex finish with shellac-based primer, using a natural-bristled paintbrush. Be careful to smooth any flaws, such as runs and sag marks, as you apply. Let the base dry for two hours.
Clean the shellac-based primer from the brush's bristles, using denatured alcohol.
Coat the dried shellac-based primer with solid stain, using the clean natural-bristled paintbrush. Let the solid stain dry for two hours; add a second coat.
Clean the solid stain from the brush's bristles, using mineral spirits.
Do not use a latex or acrylic primer, or the solid stain won't stick. Don't use an oil-based primer, or peeling will result.