41. Arc welding uses electricity to melt the surfaces of the metals in order to join them together through generators.42. Russian inventions include arc welding by Nikolay Benardos, further developed by Nikolay Slavyanov, Konstantin Khrenov and other Russian engineers. 43. A related process, plasma arc welding , also uses a tungsten electrode but uses plasma gas to make the arc. 44. Robot arc welding has begun growing quickly just recently, and already it commands about 20 % of industrial robot applications. 45. The relatively new procedure of arc welding was used extensively throughout the ship, strengthening the durability of the armour plating. 46. Motoman's arc welding system also has safety features to prevent anyone from wandering near the welder while it is operating. 47. This was one of the very first standards that covers friction stir welding, although it actually focuses on arc welding . 48. Working conditions are much improved over other arc welding processes since the flux hides the arc and no smoke is produced. 49. Copper has excellent brazing and soldering properties and can be welded; the best results are obtained with gas metal arc welding . 50. Spark gap oscillators are still used to generate high frequency high voltage to initiate welding arcs in gas tungsten arc welding .
