Why is it important to verify the base metal type before welding?

Verifying the base metal type before welding is crucial because different metals can have varying properties that significantly affect the welding process. Each type of metal has unique characteristics, such as melting points, thermal conductivity, and reactivity, which influence how the weld will perform. Different metals require specific welding processes and filler materials to achieve proper fusion and to ensure that the joint is strong and free from defects.

For instance, welding aluminum requires different techniques and filler materials than welding steel due to their differing melting points and behaviors when heated. If the wrong process or filler is used, it could lead to weld defects such as cracking, inadequate fusion, or poor mechanical properties in the final weld. Hence, identifying the correct base metal type is fundamental in ensuring a successful weld that meets the required standards and specifications.