Cleaning of Rusty Steel for Painting

Abstract

In tests on small mild steel panels, the major constituent of the salt contaminants in the rust formed in an industrial area was identified as ferrous sulphate, which confirms previous findings. It was not possible to remove all traces of ferrous sulphate from the surface of the rusty steel by abrasive blastcleaning. Small abrasive particles (150–400 p, m) were more effective in removing the salts from the pits than larger particles. An ‘in-situ’ test for estimating the amount of residual salt after various degrees of blasting has been developed. Combined abrasive and water blasting has been found to be effective in cleaning rusty steel, especially to remove the salt contaminants from pits.