What condition can prevent penetrant from seeping into a flaw during a dye penetrant inspection?

What condition can prevent penetrant from seeping into a flaw during a dye penetrant inspection?

• A. A perfectly clean surface
• B. A roughened surface
• C. Any grease or dirt on the surface
• D. Using high-viscosity penetrant

Answer: (C)

Dye penetrant testing relies on the liquid wetting the flaw surfaces and seeping into tiny cracks by capillary action. If there is a film of grease or dirt on the surface, it disrupts wetting and creates a barrier between the penetrant and the flaw. That contamination prevents the penetrant from entering the opening, so no indication shows up after the remediation steps. A perfectly clean surface allows the penetrant to wet and enter the flaws; a roughened surface doesn’t inherently stop penetration, and while very high-viscosity penetrant can hinder entry into very fine defects, the most direct and common cause of preventing seepage is grease or dirt on the surface.

Dye penetrant testing relies on the liquid wetting the flaw surfaces and seeping into tiny cracks by capillary action. If there is a film of grease or dirt on the surface, it disrupts wetting and creates a barrier between the penetrant and the flaw. That contamination prevents the penetrant from entering the opening, so no indication shows up after the remediation steps. A perfectly clean surface allows the penetrant to wet and enter the flaws; a roughened surface doesn’t inherently stop penetration, and while very high-viscosity penetrant can hinder entry into very fine defects, the most direct and common cause of preventing seepage is grease or dirt on the surface.