Strictly speaking, sandblasting and an airbrush shouldn't really be mixed up in the same article. The classic definition and image of an airbrush is that of a small, pen-like instrument that propels paint and compressed air onto a variety of surfaces. Sandblasting is the process of propelling fine pieces of abrasive material at very high velocity, many times using compressed air, to clean or etch a surface, or generally remove surface material.
Thus, the standard airbrush, which is constructed to propel a liquid substance, is not really meant to propel solids or powders. If the surface to be cleaned or etched is small, then an instrument the size and shape of the standard airbrush is used, but with some differences in usage to account for the solid material to be propelled. This would be the case in Dental Air Abrasion or in etching glass panels.
To etch glass panels a Bottom Feed Single-Action internal mix airbrush is recommended. An easel or workstation to hold the glass is needed, as well as a collector for the dust. An abrasive, usually aluminum oxide, is blasted at the glass to “white” or “snow” it, thereby making it semi-opaque. Using this technique, words or images can be sandblasted on the glass. Different shades can be created by adjusting the angle and the speed of the sandblasting.
Another way of using sandblasting to decorate glass is by carving. With a stencil to protect the parts which will not be sandblasted, the glass surface is steadily sandblasted until the design emerges. Skill and experience are needed in carving glass to produce different depths and angles which give off beautiful lighting effects.
When sandblasting was first patented in the USA in 1870, it was intended to prime a surface for the application of paint or sealant by blasting away all dust, dirt and imperfections, leaving a very smooth surface on which to paint. The process was used for large projects like the Golden Gate Bridge, or ships' hulls. Sandblasting for large projects like stripping paint off houses, cars and ships requires different equipment from that used for glass etching, and more akin to large spray guns.
The three types of sandblasting equipment are the Portable Blast Equipment, Blast Cabinet and Blast Room. For the Blast Equipment, there are dry and wet abrasive blast systems powered by diesel which pump high pressure air to pressurized tanks filled with abrasive material which then blast the material onto the surface being sandblasted. In the wet system, the abrasive is mixed with a pressurized stream of water to create a slurry.
The Blast Cabinet is a system that allows the operator to recycle the abrasive material. It consists of the blasting system, recycling system, dust collector and the cabinet that houses all of these. A Blast Room consists of the first three components of the Blast Cabinet but contained inside a room.
Although it can be done, sandblasting is not used on non-metallic materials. It is commonly used in cleaning brick, stone, concrete and metal.