Which factor can negatively impact the quality of a weld?

Poor joint preparation is crucial because it directly affects how the base materials come together during the welding process. When the joint is not properly prepared, issues such as gaps, contamination, or irregular fit-up can occur. This can lead to a variety of welding defects, including incomplete fusion, porosity, or even cracks in the weld.

Proper joint preparation involves ensuring that the surfaces to be welded are clean, adequately shaped, and compatible, promoting better penetration of the weld pool and overall integrity of the weld. Without proper preparation, even with the right technique and materials, a weld can still fail to meet quality standards, making it a critical factor in the welding process.