Before conducting a liquid penetrant test, the surface of the part must be free of which substances?

Before conducting a liquid penetrant test, the surface of the part must be free of which substances?

• A. Oil or grease
• B. Acids or chromates
• C. Traces of water
• D. All of the above

Answer: (D)

Clean, dry surfaces are essential for liquid penetrant testing. Any contaminant can prevent the penetrant from entering surface-breaking defects or distort the indications you’ll see. Oil or grease on the surface creates a barrier that blocks penetrant from seeping into cracks. Traces of water can interfere with penetrant penetration or cause misleading reflections and false indications. Residues from acids or chromates can leave films that hinder penetrant flow or affect how the developer reveals cracks. Because all of these substances can compromise the test results, the surface must be free of oil or grease, acids or chromates, and any moisture. Proper cleaning, degreasing, rinsing, and drying are essential steps before applying the penetrant.

Clean, dry surfaces are essential for liquid penetrant testing. Any contaminant can prevent the penetrant from entering surface-breaking defects or distort the indications you’ll see.

Oil or grease on the surface creates a barrier that blocks penetrant from seeping into cracks. Traces of water can interfere with penetrant penetration or cause misleading reflections and false indications. Residues from acids or chromates can leave films that hinder penetrant flow or affect how the developer reveals cracks.

Because all of these substances can compromise the test results, the surface must be free of oil or grease, acids or chromates, and any moisture. Proper cleaning, degreasing, rinsing, and drying are essential steps before applying the penetrant.