By tack welding or clamping two identical components back-to-back, welding of both components can be balanced around the neutral axis of the combined assembly (Fig 1a). It is recommended that the assembly is stress relieved before separating the components. If stress relieving is not done, it may be necessary to insert wedges between the components (Fig 1b) so when the wedges are removed, the parts will move back to the correct shape or alignment.
Fig.1. Back to back assembly to control distortion
a) assemblies tacked together before welding
b) use of wedges for components that distort on separation after welding