Shallow scratches in sheet may be repaired by?

Burnishing is the correct method for repairing shallow scratches in sheet metal. This process involves smoothing the surface of the metal by rubbing it with a hard tool, which compacts the metal fibers and reduces the appearance of scratches. Burnishing can enhance the surface finish and restore the integrity of the metal without removing material, making it ideal for minor imperfections like shallow scratches.

In contrast, buffing is typically used to polish surfaces, often enhancing gloss and visual appearance but may not effectively address deeper scratches. Stop drilling is a technique employed to prevent crack propagation, useful for managing structural integrity in specific failure scenarios, while welding is more suitable for joining materials or repairing significant damage, not superficial scratches. Thus, burnishing stands out as the most effective and appropriate choice for repairing shallow scratches on sheet metal.