Which of the following is NOT a generally accepted method for applying penetrants?

Rubbing the penetrant over the surface is not a generally accepted method for applying penetrants. This application technique can lead to uneven distribution of the penetrant on the surface, which may cause inadequate coverage and potentially miss defects during the testing process. Effective penetration requires the penetrant to be uniformly applied, typically using methods such as brushing, spraying, or dipping.

Brushing is a common method as it allows for controlled application on the surface area, while spraying can offer a quick and even coating, especially on larger surfaces. Dipping ensures the part is fully submerged in the penetrant, achieving a uniform layer over complex geometries. Each of these methods is designed to optimize the ability of the penetrant to seep into any surface-breaking flaws, ensuring reliable detection during assessment.