How can cutting oils be effectively removed from parts before penetrant testing?

Vapor degreasing is an effective method for removing cutting oils from parts before penetrant testing due to its ability to efficiently clean complex surfaces without leaving residues that could interfere with the testing process. This method takes advantage of the solvent's vapor to condense on the cooler surfaces of the part, effectively dissolving oils, greases, and other contaminants.

Vapor degreasing is particularly useful because it minimizes physical contact with the part, which can protect delicate or intricate surfaces from being scratched or damaged. Additionally, it allows for thorough cleaning in areas that are hard to reach by other means.

In contrast, other methods such as wiping with a dry cloth might not remove all oils and could potentially smear contaminants. Using a cloth soaked in water may not be effective since water can mix poorly with oily substances, leading to inadequate cleaning. Manual scraping could remove some debris but risks damaging the surface and may not completely eliminate fine contaminants.