Prior to the test, the area to be inspected and at least one inch on either side shall be free from all contaminants (dirt, grease, lint, slag, spatter, oil, scale, water and protective coatings).
It is recommended by the manufacturer, welded components or parts cleaned by Vapour degreasing, organic solvents or detergents, and properly protected from contamination, need not be re-cleaned with penetrant cleaner (remover) prior to application of the penetrant.
A wire brush may be helpful in removing rust, surface scale, but it is used only when no other means of removal will surface.
MICRO NDT SOLUTIONS & TRAINING INSTITUTE 