Inspection of Surface Treatment

• Residual weld oxides cause of insufficient cleaning.
• Rough Surface cause of overpickling, direct sunlight when pickling, inter crystalline corrosion.
• Shading finish cause of organic contamination, uneven appilcation.
• Discoloration cause of pickling residues in crevices, surface contaminants, insufficient cleaning, contaminated rinse or poor rinsing.
• Water Stains cause of dust, contaminated rinse water and others.

The PH value of final rinse water gives a rough indication of residual acids. The PH value of rinsing water after used should have value more than 7. Take more attention to tight corners, narrow crevices, incomplete penetration area, rough area, and others.

The water break test is a simple way of assessing the effectiveness of degreasing. A thin sheet of water that is applied to the surface will break around any surface contamination.

Simple test that is often used is to repeatedly make wet the surface with tap water and allow it to dry on surface with about 24 hours test period. Any residual iron rust is visible with corrosion colour around tap water area after the test cycle.