A method of arc welding a first metal piece to a second metal piece includes the steps of extend a welding head between the space between first and second metal pieces, bending a filler wire, passing the bent filler wire through the welding head such that an end of the bent filler wire extends in a direction toward a surface of one of the first and second metal pieces, and arc welding the end portion of the bent filler wire onto the surface of the metal piece. The method further includes rotating the end of the bent filler wire toward another surface of the metal pieces and arc welding the of end of the rotated bent filler wire onto the surface of the another metal piece. The welding head travels along the space between the first and second metal pieces as the step of arc welding occurs.