The sandblasting of metals is a valid method of preparation of metal surfaces-type steel before painting or the application of solutions that are protective against rust.

The surface must have characteristics that warrant a good anchoring base for the paint or solution protective.

For this reason you need to clean it from the dirt is substances foreign to its original nature.

In fact, on the surface of artifacts in the metal used in the building industry there may be different substances, rust, scale and oxidation, as well as residues of old paints, and other things foreign that prevent the effectiveness of the protective system since it creates levels between the true metal and the layer of rust, resulting in poor stability and grip.