This is a semi automatic version of SMAW. A specially designed heavy - coated electrode, which can be of any length upto 2 m, is laid on the seam of a grooved butt joint or along the root of a tee joint. It is then clamped down with a water - cooled copper bar heavy square section, which is grooved to accommodate the electrode. The copper bar is nearly as long as the electrode. The bare end is clamped in a holder. The arc is struck at the striking end and the electrode gradually consumes by itself, making the butt or fillet weld of the same length as the electrode. The copper block helps to prevent overheating of the electrode and to maintain intimate contact between the electrode and the joint.