Maintenance of joint opening during welding is important. Clamping to prevent joint movement during welding is recommended. If tack welds are used, the same care in cleaning and inert gas shielding must be exercised, as with any and all titanium welds, to prevent contamination. Any cracked or contaminated tack welds must be removed before final welding. Inclusion of these foreign substances in titanium weld metal could degrade properties and corrosion resistance.
Weld wire is clean as packaged by the manufacturer.
If wire appears to be dirty, wiping with a non-chlorinated solvent, prior to use, is good practice. In severe cases, acid cleaning may be required. All joint surfaces and surfaces of base plate for a distance of at least an inch back from the joint need to be cleaned. Normal pickled mill surfaces generally require only scrubbing with household cleaners or detergents, followed by thorough rinsing with hot water and air drying. The solvents are particularly effective in removing traces of grease and oil.