If you've been involved in a home remodeling project, you understand the joy of laying your eyes on newly installed drywall -- a sure sign your project is just steps away from completion. Now you must prepare the drywall for painting. Your biggest challenge will be dust, which drywall can conceal masterfully. As soon as you bust the dust, apply primer to the drywall.
Inspect the drywall for nicks or gouges. Fill them with drywall mud or make your own paste with 3 parts baking soda and 1 part white glue.
Don a face mask and sand the drywall with a pole sander by applying light pressure. Sand in a circular motion, rather than from side to side, to avoid putting scratches in the drywall.
Put the brush attachment on your vacuum and remove dust from the wall. Work from top to bottom in small, workable sections. Run a dark-colored rag over the drywall. If you see any white dust on the rag, vacuum the drywall again.
Pour 1 cup of white vinegar into a bucket and fill it with 1 gallon of water. Use a large cellulose sponge to wash the wall thoroughly, again working from top to bottom. If the water in the bucket turns several shades darker before you are finished, make a fresh batch of the vinegar-water solution.
Let the wall dry thoroughly. Direct a fan on the drywall if the air is humid. The drywall must be bone dry when you prime and paint it to ensure that no mildew or mold festers underneath the subsequent primer and paint.
Prime Before Painting
Run a microfiber cloth over the drywall as a final guard against dust, which will diminish the quality of your painting efforts. Do this right before you are ready to apply the drywall primer. A high-quality, latex drywall primer will seal the wall and ensure that the paint absorbs evenly, without splotches.
Apply the primer exactly like paint – cutting in around the ceiling, baseboard and edges with a brush and working the wall with a roller. Work in small, 2- or 3-foot sections and from top to bottom. It might help to make a large "W" or "M" with the roller and then fill in the area until it's covered. Keep a wet edge as you work and don't be surprised if the primer absorbs quickly; it's not called "drywall" for nothing.
Run your hand over the primer after it dries. If it's rough, sand it lightly with fine-grit sandpaper. Run a clean microfiber cloth over the wall before painting.