The first step to performing sandblasting is pouring the sand into the sandblasting machine. Sandblasting machines have a chamber on top in which the sand is poured. The sandblasting machine is then connected a conventional air compressor that, when activated, propels the sand out through a handheld nozzle. Depending on the settings, the pressure of the sand may be anywhere from 50 to 130 pounds per square inch (PSI).
The sand is then “blasted” across the surface, and because of its abrasive properties, the sand is able to create a smoother surface. Concrete, for example, is often sandblasted. After the concrete has been poured and allowed to dry, it is treated with sandblasting. The process removes some of the excess material on the concrete, which in turn makes it smoother.