Paint Brushes, Rollers, Sprayers and Sandpaper

Brush, roller or sprayer: matching the tool to the surface

Brush bristles should suit the paint. Synthetic nylon or polyester brushes work with water-based paints because natural bristles absorb water and go limp, while natural bristles are traditionally used with oil-based finishes. A roller's cover nap sets how much paint is carried: a quarter-inch nap suits smooth surfaces, three-eighths to half-inch suits light texture, and thicker covers suit rough masonry. Frames and covers must match in length and cage diameter.

Sprayers finish large areas fast but need masking and thinning knowledge. On most airless tips, the tip number encodes the result: the first digit doubled gives the fan width in inches at a standard distance, and the last two digits give the orifice size in thousandths of an inch, so a 631 tip makes a 12 inch fan through a 0.031 inch opening. Thicker coatings need larger orifices; stay within the sprayer's maximum tip size.

Sandpaper, flap discs and wire brushes: grit and speed rating

Surface preparation makes or breaks a paint job. Sandpaper grit runs from coarse, 40 to 60, for stripping and shaping, through medium, 80 to 120, for smoothing, to fine, 150 to 220, for finishing between coats. Aluminum oxide lasts longer on hard surfaces; garnet is common on wood. Flap discs for angle grinders carry a maximum speed in RPM, and it must be at or above the grinder's speed.

Wire brushes remove rust and loose paint but leave scratches that must be sanded. Brass bristles are softer on metal, and steel is more aggressive. Sprayer accessories are model-specific as well: a spray cup kit lists its filter in microns and its capacity in ounces, and a tip must fit the guard and holder of the same sprayer family. Touch-up paint in small tubs is matched by color and finish.

Questions about Paint Brushes, Rollers, Sprayers and Sandpaper

What roller nap should I use?

Use about 1/4 inch for smooth walls and doors, 3/8 to 1/2 inch for light texture or ordinary drywall, and 3/4 inch or more for stucco, brick and block. Longer naps hold more paint but leave more texture, so do not use them on smooth surfaces.

Natural or synthetic brush bristles?

Synthetic bristles suit water-based paint and also work with oil-based finishes, so they are the safe general choice. Natural bristles are normally used with oil-based paints and varnish, and they soften and lose shape in water-based paint. Choose the brush size to the area.

What grit sandpaper should I use between coats?

Between coats of paint or varnish, a fine 220 grit removes dust nibs and raised grain without cutting through the finish. For bare wood before the first coat, work through 80 to 120, then 150. Always wipe off the dust before applying the next coat.