Airman 1st Class Joshua Soucy, 28th Maintenance Squadron aircraft metals technician, turns on the shielding gas machine at the welding shop on Ellsworth Air Force Base, S.D., Aug. 16, 2013. Shielding gas, made up of 75 percent Argon and 25 percent Carbon Dioxide, protects the emanating melting heat from the surrounding atmosphere, stabilizing the electric arc which fuses together the pieces being welded. (U.S. Air Force photo by Airman 1st Class Anania Tekurio/Released)