When using cathodic cleaning, what is the arc passed over?

Cathodic cleaning involves using the electrical current from an arc to clean the surface of a metal workpiece, specifically the base material. In this process, the arc is applied over the base material without melting it, acting as a means to remove impurities, oxides, or contaminants from the surface. This creates a clean, oxide-free environment that is crucial for achieving a strong and effective weld.

This technique is particularly useful in preparing surfaces prior to welding, as it enhances the integrity of the joint by ensuring that the material is as clean as possible. The ability to clean without melting the base material allows for a more controlled and precise preparation, reducing the risk of compromising the integrity of the material itself.

Other options, such as passing the arc over the newly welded joint, the surrounding area, or the gas flow, do not accurately describe the specific action or purpose of cathodic cleaning, which focuses on the direct cleaning of the base material.