Which method can be used to check for porosity in a weld?

The method that involves both visual inspection and non-destructive testing methods is essential for checking for porosity in a weld. Visual inspection allows the welder to identify surface defects, including any signs that may indicate porosity, such as small holes or pinholes on the weld surface. Non-destructive testing methods, such as ultrasonic testing or dye penetrant inspection, can uncover subsurface defects without damaging the weld itself.

Porosity often occurs due to entrapped gas during the welding process, and it can significantly affect the integrity of the welded joint. Thus, utilizing both visual and non-destructive testing provides a comprehensive approach to detecting such defects effectively.

Other methods listed, such as pressure testing, can assess the overall integrity of a weld but are not specifically designed for identifying porosity. Manual grinding of the weld can alter the weld's surface and possibly hide defects rather than revealing them. Welding in direct sunlight does not address the detection of porosity and instead can introduce challenges like increased oxidation or inconsistent weld cooling. Therefore, the combination of visual inspection and non-destructive testing is the most reliable approach to check for porosity in welds.