GTAW WLD 150 Welding Practice Test 2026 – Complete Exam Prep

Non-heat repair methods are preferred when working with metals that are difficult to weld, such as cast iron, because heat from welding can cause the brittle metal to crack or warp as it cools. Cold mechanical repair restores function without melting or heating the base metal, using mechanical fastening, peening, or bonding to rebuild the part. This avoids introducing thermal stresses and distortion, making it a safer, more reliable option for cast iron than methods that involve high heat. Welding, brazing, and soldering all involve heating, which can promote cracks or weakened joints in cast iron, so they are less suitable for repairs on these materials.