What cleaning is required after completing a weld?

The requirement for cleaning after completing a weld primarily focuses on ensuring that any slag and impurities that can affect the integrity and appearance of the weld are removed. Complete slag removal is critical because during the welding process, slag can form on the surface of the weld bead. If left unattended, this can lead to defects such as porosity or weak spots in the weld, affecting its strength and durability.

Following the removal of slag, brushing or utilizing other suitable methods helps to prepare the surface for any subsequent treatments, such as inspections or coatings. This process ensures that the weld is clean and free of contaminants that could interfere with further operations.

While brushing alone might seem sufficient, it does not address the initial need for complete slag removal, which is essential for quality assurance. The application of protective coatings should indeed happen, but only after ensuring a clean surface; therefore, it is not sufficient as the sole method of post-weld cleaning. Chemical cleaners are useful but may not be suitable as the only method, particularly since they could leave residues that impact the weld quality.

Therefore, the correct answer encompasses both the removal of slag and ensuring the weld surface is adequately prepared for any future treatments, making it the most comprehensive and effective choice.