Thorough shot blasting 

Shot blasting consists of attacking the surface of a material with one of many types of shots. Depending on the type of surface to be cleaned, our shot-blasters use a suitable material to achieve the desired result. Contact J R Finishright Ltd for details if you are in West Sussex. 

The device that throws the shot is either a large air gun, or spinning paddles which hurl the shot off their blades. The shot can be sand, small steel balls or granules of silicon carbide. Normally this is done to remove something on the surface such as scale, but it is also done to create a particular surface type on the object being shot blasted.