A welding method and system (4) using a robotic arm (10), a welding robot (18) and a welding table (2) placed at an angle from horizontal to hold two C-channels (6 and 8) facing each other to maintain position and be welded together. C-channels (6 and 8) face each other to form a closed channel at increased welding speed with less materials having resulting benefits including constant welding, less distortion, and less welding material. Welding begins with restraining C-channels (6 and 8) in conjunction with the angled welding table (2). A robotic arm (10) handles C-channels (6 and 8) to move, place and restrain them relative to each other and the welding table (2). A pressing tool (12) may be a set of pressure-exerting tools (26). A welding robot (18) with a seam finding system (24) preferably welds the restrained C-channels (6 and 8) from top to bottom.