Sandblasting
Sandblasting, sometimes referred to as bead blasting, is the easiest, quickest way to remove old paint, rust, dirt and grease from metal and other hard surfaces. It's also used for removing paint (such as graffiti) and discoloration from stone and brick buildings, for etching frosted decorations on glass, stone or tile and for "weathering" wood and carving wood signs.
A sandblaster works on the same principle as a paint sprayer. Compressed air at high pressure is used to blow fine sand or other abrasive material through a hardened spray nozzle. The abrasive particles quickly eat away whatever they are directed at, leaving a clean, matte surface. They will also begin to eat away at the actual surface of the object, so care must be exercised to avoid damage.
Sandblasting is a chore best suited to service professionals because of the mess involved, environmental requirements, and the care needed to keep from over-blasting the area being cleaned. Sandblasting is intended for jobs that require some stripping and abrasion.
-- Tips courtesy of HomeAdvisor.com