Liquid Penetrant Testing Level 2 (PT-2) Practice Exam

Which of the following is not normally recommended?

1. Performing a fluorescent penetrant test following a visible penetrant test

2. Performing a visible penetrant test following a fluorescent test

3. Removing excess penetrant with a water spray

4. Removing excess penetrant with towels moistened with solvent

The correct answer is: Performing a fluorescent penetrant test following a visible penetrant test

The preference for performing a visible penetrant test first, followed by a fluorescent penetrant test, aligns with best practice recommendations in liquid penetrant testing. Each type of penetrant—fluorescent and visible—has distinct characteristics that influence how they reveal flaws. When a fluorescent penetrant is used, it contains dyes that fluoresce under UV light, making it highly sensitive to small defects. If a visible penetrant is applied afterward, it can obscure or interfere with the fluorescent indications, making it difficult to interpret results accurately. Therefore, it is not normally recommended to perform a fluorescent penetrant test following a visible penetrant test, as the visible penetrant's properties can hinder the effectiveness of the fluorescent test. In contrast, using a water spray to remove excess penetrant is common practice, as water is an effective method for washing away excess penetrant without leaving residues that could mask indications. Using towels moistened with solvent is also a valid method for excess penetrant removal, provided that the solvent is appropriate for the specific penetrant being used and doesn’t compromise the testing surface. Overall, the correct choice highlights an important aspect of test sequence and methodology that ensures the integrity and reliability of liquid penetrant testing results.