Sanding serves to remove imperfections on walls, ceilings, furniture, floors, etc.
Sanding serves to remove imperfections on walls, ceilings, furniture, floors, etc. It is also used to roughen surfaces too glossy for paint or filling compound to adhere easily. Steel wool and sandpaper are the most commonly used abrasive materials for this purpose. Sanding can be performed by hand or with electric tools.
Steel wool is used for cleaning, stripping and polishing metals, wood, etc. Types of steel, bronze and copper-based wool are good for surfaces exposed to water. You can use them to sand wood if you apply water-based or micro porous finishing products. Other types of steel wool leave traces that could imbed themselves in the wood and rust on contact with water.
The degree of roughness in steel wool range from extra-coarse (4) to extra-fine (0000). Very coarse wool (3) is used to smooth rough surfaces and remove varnish or paint during stripping. Coarse wool (2) is used to remove old paint and rust. When soaked with solvent, it easily removes grease and wax. Fine wool (0) is used to clean painted surfaces, trim and floors. Extra-fine wool (0000) is used to rubdown paint, varnish and shellac before applying a final coat. It also serves to polish surfaces and give them a satin finish.
Sandpaper consists of grains of aluminum oxide, emery, garnet, or silicon carbide glued to a backing. This backing may be paper, cloth, fibre, plastic or a combination of paper and cloth. The grains may be open or closed. Closed grains crush more easily during use. Sandpaper comes in sheets, belts and disks and in various grades of coarseness.
The coarseness of certain types of sandpaper is graded from 12 to 600. The higher the number, the smaller the grains. Other kinds of sandpaper come in three grades: coarse, medium and fine. The type of surface and its condition determine which grade should be used. Coarse paper is used to make rough surfaces smooth as quickly as possible. Finer paper is used to eliminate traces of the coarser grades. The following two charts present the main types of sandpaper and their different uses.
Aluminum oxide Tough synthetic abrasive. Its grains break during sanding, thus restoring coarseness. It is used to smooth and strip bare metals and wood.
Silicon carbide Synthetic abrasive. Its grains wear down during sanding. Used for sanding gypsum (drywall), synthetic surfaces and concrete and also applied between coats of paint or finish.
Emery Fine and natural abrasive glued to cloth and used on metal.
Garnet Natural abrasive, the grains of which wear down during sanding. Use to sand bare wood.
Before you start sanding, make sure you are using the right sandpaper for the job by testing it on a hidden patch of the surface. Use a sanding block appropriate to the surface if you plan to sand by hand. The block helps you apply even pressure across the surface and so makes sanding easier. You can buy such a block or make one yourself with a properly sized piece of wood.
Electric sanders are faster and often more effective than hand tools when doing a large quantity of work, but they also require more skill. These tools include belt sanders, vibrating sanders, disk sanders and floor sanders.
Start with a coarse aluminum oxide or garnet sandpaper and end with a finer (80, 120, 180, 220) sandpaper.
Sand with the grain to avoid ripping the wood fibres.
Start with a coarse silicon carbide sandpaper and end with a finer (100-150) sandpaper.
Sand in a circular motion.
Start with a coarse silicon carbide sandpaper and conclude with a finer (80, 120, 180, 220) sandpaper.
Rub surface in a circular motion, smoothing edges of the old paint job.
Remove dust occasionally by vacuuming or striking the sandpaper on a hard surface. Replace sandpaper when it becomes encrusted.
Fold sandpaper occasionally for a new sanding edge.