Instructions for Welding Titanium: Titanium is generally welded using the same techniques as stainless steel, however, titanium requires much greater weldjoint cleanliness along with extensive inert gas shielding. •Cleaning: Grind or file away mill scale. Remove surface oxides with SÜA Pickling Paste  or 35% nitric – 5% hydrofluoric acid solution at room temperature. Remove any grease or oil with a nonchlorinated degreasing solvent, methanol acetone, or methyl-ethyl-ketone. Light oil can be removed by washing with a household abrasive or detergent. •Fitup: Clamp joints where possible. Tack welds require the same care as other welds. •Equipment: Use a constant-current power source (DCEN) for GTAW with a contactor for arc start and stop. High-frequency starter for manual welding, water-cooled GTA torch with gas lens and ¾-inch (#12) gas cup, 2% Thoriated, 2% Ceriated, 2% Lanthanum or Rare Earth tungsten Note: A reactive metal, titanium is sensitive to embrittlement by oxygen, nitrogen and hydrogen. Consequently, the molten weld metal must be protected against atmospheric contamination by holding the shielding gas over the weld zone until it cools down to 600°F