What is the first step in conducting a liquid penetrant test on a painted surface?

The first step in conducting a liquid penetrant test on a painted surface is to ensure that the surface is clean and free of any contaminants that may interfere with the test results. This includes removing any paint, coatings, or other substances that could mask defects in the material being inspected.

In non-destructive testing like liquid penetrant testing, it is crucial for the penetrant to have unobstructed access to the surface to detect any flaws. If the paint or other coatings are not fully removed, it could prevent proper adhesion and penetration of the testing solution into any cracks or voids present in the substrate. Following this step, the surface can then be tested for cleanliness to ensure that there are no residues that may interfere with the testing process. After these preparations, the penetrant can be applied and the inspection can begin.

While the other choices might be part of the testing process at a later stage, they do not represent the essential first step needed to prepare the painted surface for an accurate and effective liquid penetrant test.