How to Choose and Use Sandpaper

Sandpaper is available in grades intended for industrial and commercial usage. Commercial sandpaper is used by hobbyists and for nonprofessional uses. Sandpaper can be purchased at discount, hardware, craft and home improvement stores. Sandpaper is classified by grit number, where the number is based on the per-inch amount of abrasive granules on the sandpaper. The higher the grit number, the smoother the paper. Choosing which sandpaper to use is based on the material being sanded and the task being performed. Sandpaper can be used alone or wrapped around a sanding block.

How to Choose Sandpaper

• 1

  Match the project to the type of sandpaper. Read the packaging on the sandpaper. According to "This Old House" magazine, in the article "Choosing and Using Sandpaper," there are many types of sandpaper, such as garnet or silicon carbide, but aluminum oxide is most commonly used for sanding wood, paint and metal. Different types are recommended for different woods or materials.

• 2

  Match the grit number to the task. Begin with a lower grit number, such as 80 grit, for the initial sanding stages when the material is rough. If the object is relatively smooth to begin with, start with a higher grit number. According to "This Old House" magazine, the rule to remember is the bigger the size of the grit (meaning the lower the grit number), the larger the scratches made by the sandpaper.

• 3

  Select the sandpaper recommended for the surface contours of your object. Some sandpaper types, such as aluminum oxide, are good for flat surfaces or contours. Sandpaper is available as paper that can be cut into strips or squares with scissors, and and as sandpaper-covered sponges. If your object will be oiled as you sand, choose a wet and dry sandpaper, such as silicon carbide. According to Tomball Rental Center, in the article, "How to Choose Sandpaper," silicone carbide sandpaper is abrasive enough to smooth metal, varnish and assorted hardened surfaces.

How to Use Sandpaper

• 1

  Cut the sandpaper into a square large enough to hold comfortably in your hand or cut the sandpaper in a strip that will fit around a block of wood or plastic sold as a sanding block. Any block of wood will work. Sandpaper can be taped to the block with duct tape.

• 2

  Sand the highest or most uneven places on the object first. Hold the sandpaper firmly while pressing down onto the object with the paper and moving your hand in a straight, back-and-forth motion. Always sand the wood in the direction of the grain.

• 3

  Sand small crevices or holes by wrapping and taping strips of sandpaper around an appropriate sized wooden dowel. Insert the dowel and sand in a back and forth motion as the space permits.

• 4

  Switch to a higher grit, such as 100 grit, sand, and repeat with increasingly higher grits of sandpaper until the workpiece is smooth to the touch. According to Tomball Rental Center, the harder the wood being sanded, the more cycles of grit will be necessary. For pine, sand with 80 to 120 grit. For maple, you might go as high as 400 grit to reach a satin smoothness.

• 5

  Brush the object in a back and forth pattern with a clean, dry paintbrush to remove sanding residue before painting, staining or finishing. Leaving sanding residue on the object will result in flecks of sanded wood in your paint or stain.