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

What is a generally accepted method for removing excess non-water washable penetrant?

1. Blowing air across the surface

2. Wiping the surface with a cloth dampened with cleaner

3. Soaking in a solvent solution

4. Scrubbing with a brush

The correct answer is: Wiping the surface with a cloth dampened with cleaner

The preferred method for removing excess non-water washable penetrant involves wiping the surface with a cloth dampened with cleaner. This approach effectively minimizes the risk of disturbing the penetrant that has entered any discontinuities in the material, which is crucial for ensuring the reliability of the test results. Using a cloth allows for controlled application of the cleaner, ensuring that excess penetrant is gently removed without harming the surface or affecting the penetrant that needs to remain for detection of defects. It's also a practical method because it reduces the chance of spreading the penetrant to adjacent areas. Other methods may not effectively achieve the same balance between thoroughness and delicacy. For instance, blowing air across the surface can lead to airborne contaminants and may not adequately remove the penetrant. Soaking in a solvent solution could wash out penetrant from cracks or defects, leading to misleading results in the inspection process. Similarly, scrubbing with a brush could force excess penetrant deeper into the surface irregularities rather than removing it, thus compromising the integrity of the inspection. Therefore, using a cloth dampened with the appropriate cleaner stands out as the most effective method in this context.