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

If penetrant is difficult to remove from a part due to an extended penetration time, what can be done?

1. Wipe the part with a cloth

2. Re-dipping the part

3. Using a stronger solvent

4. Letting it dry before rinsing

The correct answer is: Re-dipping the part

In situations where penetrant is difficult to remove due to an extended penetration time, re-dipping the part is an effective method. This approach works because re-dipping allows the fresh penetrant to interact with the existing penetrant, which can help to loosen it and facilitate its removal. When the part is re-dipped, any older penetrant that has not been adequately permeated into defects and is merely on the surface can be effectively blended with the new penetrant, thus improving the overall removal process. Furthermore, it can assist in ensuring that the penetrant that remains in the part's surface features is more thoroughly displaced. This technique is particularly useful in ensuring that all relevant penetrant has either been penetrated into defects or is removed, ensuring a more reliable inspection outcome. Other options such as simply wiping the part or letting it dry before rinsing are not likely to be effective solutions as they do not address the underlying issue of the penetrant adherence. Using a stronger solvent may seem like a potential solution, but it could also damage the part or interfere with the inspection process if not used correctly.