Liquid Penetrant Testing Level 1 (PT-1) Practice Exam

Which method is considered more acceptable for cleaning parts prior to penetrant testing?

1. Using sandblasting

2. Using wire brushing

3. Chemically soaking the parts

4. Using a cloth rag

The correct answer is: Using wire brushing

Using wire brushing is considered more acceptable for cleaning parts prior to penetrant testing because it effectively removes surface contaminants such as oil, dirt, and loose debris without damaging the substrate material. Wire brushing can reach into crevices and irregular surfaces, ensuring that the part is clean and adequately prepared for the subsequent penetrant application. In the context of penetrant testing, a clean surface is critical to ensure that penetrants can effectively enter any discontinuities in the material. In contrast, methods such as sandblasting might alter the surface profile too much or introduce additional surface contamination. Chemically soaking the parts could leave residues or interfere with the penetrant's ability to enter flaws. Using a cloth rag may not adequately clean the surface, especially in areas with more stubborn contaminants or geometrical complexities. Therefore, wire brushing represents a balanced approach, combining effectiveness in cleaning without compromising the integrity of the component being tested.