Which of the following practices helps to prevent weld contamination?

Cleaning the base metal before welding is essential in preventing weld contamination. Any surface contaminants such as rust, grease, oil, dirt, or other foreign substances can interfere with the welding process and negatively affect the integrity of the weld. When contaminants are present, they can lead to defects like porosity, incomplete fusion, or slag inclusion, ultimately compromising the strength and quality of the weld joint.

Properly preparing the base material by thoroughly cleaning it ensures that the molten metal fuses effectively with the base metal, creating a strong and reliable weld. Techniques such as grinding, sandblasting, or using chemical cleaners can be employed to ensure the surface is clean before welding begins, thus promoting optimal bonding conditions.

In contrast, other practices mentioned may not directly address the root cause of contamination. For instance, using a larger wire diameter might influence the weld size and shape but does nothing to ensure the surfaces being joined are free from contamination. Similarly, increasing travel speed could potentially affect the heat input and weld quality but would not remove any contaminants present on the base metal. Welding outdoors in the wind may introduce additional contaminants, such as dust and debris, rather than preventing them. Therefore, cleaning the base metal is the most effective practice to maintain the quality and integrity