If you have a look at the walls inside your home and notice waves, ripples and humped regions of drywall compound throughout the paint, this means that the wall wasn’t sanded correctly before painting. Sanding removes pits, pockmarks, stripes, runs and thick gutters chemical buildup, leaving ceiling and wall surfaces smooth. In many cases, painting shingles without sanding makes these imperfections even more noticeable, which can seriously affect the general look of a space.
Sand the paint and any high spots in the gutters chemical smooth, so that it is flush with the walls. Start with a coarse-grit sanding moderate; rough grit removes more material at once.
Skim pits, pockmarks and holes with fresh drywall compound along with a drywall knife. The target is to create low spots even with the remainder of the wall.
Sand the wall with medium grit once the chemical has dried, paying additional attention to the locations that required skimming and sanding.
Inspect the wall for light scratches and air bubbles in the drywall compound. Apply a thin skim coat of fresh chemical to fill in these tiny imperfections.
Sand the regions that required scratch fixes, filling in and leveling high spots, this time using a fine grit to complete the smoothing of the surfaces.
Roll a coat of primer sealer over the entire wall and allow it to dry.
Roll on one coat of paint, allow it to tack dry, then roll on the finish coat of paint.