Shot and sandblasting are the best method for removing rust, mill scale or unwanted coatings from metal surfaces.

The required level of surface roughness should be specified in the surface treatment specification, which will indicate the average surface profile that the blasting process should aim to achieve and the suitable blasting media to use.

After the surface has been cleaned, it is essential to prevent the steelwork from deteriorating. Depending on the length of time that the steel has been left without protection and the amount of moisture present in the air, the re-rusting process can occur very quickly therefore the surface must be recoated as soon as possible. Otherwise, there's a possibility that the paint coating will be compromised or fail.