Power Tool Cleaning - For the removal of loosely adhering mill scale, paint and dust, this is more effective and less laborious method than hand tool cleaning. It will not however remove tightly adhering mill scale. Power wire brushes, needle guns grinders and disc sanders are generally used. Care should be taken, particularly when using power wire brushes, not to polish the metal surface, as this will reduce the key for subsequent painting. Methods are described in SSPC-SP3 and should be to ST3 grade of Swedish Standard or ISO 8501-1: 1998.