Move the aluminum object to an open workspace or ventilate the space where the immovable surface is located. Clear the worksite of materials that may be struck with stray sand, and cover all other vulnerable surfaces with heavy plastic sheeting.
Put on your safety goggles as well as a respirator if you are working indoors. For the best protection, wear a hooded painter's suit to cover your skin and hair.
Check the valves on the sandblaster to ensure that they are shut off. If the unit has a cylindrical tank, use a funnel to pour a bag of silica sand into the spout at the top. For a rectangular sandblaster tank, simply lift the protective lid and pour the sand accordingly.
Start the compressor according to the manufacturer's label or instruction manual. The blaster will be ready for use once it pressurizes between 40 and 100 PSI.
Adjust the blaster to a low pressure setting initially. Hold the nozzle at least 8 inches from your body and point it at the aluminum you wish to sandblast.
Hold down the trigger and clean the aluminum surface from top to bottom. Use controlled sweeping motions to clean the bare metal, or use short bursts of sand to remove paint and other finishes. Gradually raise the pressure as needed until your desired results are achieved.