Sandblasting wood is a method of removing old finishes such as paint, shellac, or varnish from wood and removing material from a wood surface to create a sign or a piece of art. Tips on sandblasting wood are similar in terms of safety precautions, but differ in the material and equipment used for each purpose. The process involves an abrasive material applied with force to exposed wood or exposed finish covering wood, resulting in a design incised into the wood that is stripped of old paint and ready for refinishing.
Sandblasting wood to create art or signs typically requires a portable pressure blaster with a hose to a hand-held nozzle used to accurately direct the flow of high-pressure abrasive on the portions of the object to be removed. Portable sandblasting equipment generally consists of an air compressor, a reservoir for abrasive material, a propulsion system, and a hose terminating in a nozzle. Nozzles are available in a variety of shapes and sizes, depending on the requirements of the project.
For accurate wood engraving using abrasive blasting, a stencil or template should be applied to the surface to be engraved. A stencil is a pattern that protects the surface to be untouched by the abrasive blasting. Stencils or templates may be as simple as vinyl shelf paper on which a design is traced with carbon paper, or as sophisticated as special film processed in a machine that will produce a photo image. In the simpler methods, a cutting tool such as an X-Acto knife is often used to cut away the material from the area to be carved.
When working on a wood engraving, it is important to take small layers of wood off at each pass. The nozzle should be kept moving over the exposed area and shouldn't be concentrated on any one place for too long in order to achieve uniform engraving. When using portable sandblasting equipment, it is extremely important to wear protective eye wear because portable units typically do not have a dust collector.
Sandblasting is also used for industrial cleaning and paint removal from wood. These applications of sandblasting wood are typically done in a blast cabinet, an enclosed cabinet housing all the functions of the portable blaster within a small shop. The item to be cleaned or stripped is placed in the cabinet, and the process is accomplished in a contained environment. Usually blast cabinets have windows for monitoring progress to ensure that cleaning or stripping is complete and that the wood is not damaged.
While silica sand is frequently used in sandblasting wood, media including natural products such as walnut shell and metal particles can be used as abrasive material, depending upon the project requirements. Silica sand is available in a variety of grits from 30 to 220 for different applications. As with sandpaper, larger numbers indicate smaller particles. For sandblasting wood, grits from 30 to 80 are generally recommended.