How to Paint Walls That Have Residual Sizing

Move all furniture away from the walls.

Lay a drop cloth on the floor in your work area. This will collect any dust that falls as you do your surface prep, and it can be reused to catch any spatter or spills that occur during painting.

Rub the sanding block over any portion of the wall that has a gritty residue until the wall feels smooth. The sizing and other residual adhesives should come off easily with only a moderate amount of dry scrubbing motion.

Mix up a bucket of trisodium phosphate or a TSP substitute in hot tap water according to the instructions on the package's label. These cleaning products are available in powdered form or as liquid concentrates.

Slip on a pair of rubber gloves. Then dip a sponge in the bucket, and squeeze out most of the TSP so the sponge is not oversaturated. Wipe down the wall, rewetting the sponge frequently. Follow up by rinsing the TSP off the wall, using a sponge lightly soaked in water. Allow the wall to dry completely.

Fill any small holes or uneven areas in the wall with spackling compound. Use a putty knife to smooth the spacking material evenly into the wall.

Apply a shellac primer to the wall using a roller. Use a paintbrush for areas near doors, window frames, the ceiling and other areas that require more detailed application. The shellac will seal off any residual sizing or adhesive from interacting with your finish coat.

Apply an acrylic latex topcoat using a roller and brushes as before. Acrylic latex paints form a more impervious finish than other latex paints and offer added life expectancy, enhanced dirt-resistance and other advantages.