Why is it essential for the workpiece to be free from oils and impurities before welding?

It is essential for the workpiece to be free from oils and impurities before welding because contaminants can lead to defects and significantly lower weld quality. When oils, dirt, or any other impurities are present on the metal surface, they can create barriers that affect the fusion between the base material and the filler rod. This can result in porosity, weak joints, and overall compromised integrity of the weld. Proper cleaning of the workpiece ensures that a strong, uniform bond can be formed during the welding process, which is critical for the durability and performance of the final product. Ensuring a clean surface is a fundamental step in achieving high-quality welds in Gas Tungsten Arc Welding and other welding methods.