1. weldment preheating, copper welding rod drying To improve the welding quality, the weldments are preheated to 300-350 degrees before welding and the electrodes are baked for 1 hours at 150-200 degrees. 2. way method The copper welding strip can be welded by linear strip method, the faster the better, the better the metal oxidation. The diameter of welding rod and welding current are increased in the permit range of the welding parts. When the V shaped or X shaped groove is welded, the defects may appear in the root. The reason is that the welding rod is too thick, the angle of the groove is small, the arc is too far from the root, and the heat conduction of copper is fast. The arc heat is insufficient, so in order to ensure the penetration of the root, the angle of the groove should be increased and the gap should be increased properly. The first layer of the welding rod with a diameter of 3-4 millimeters is the best, the diameter of the electrode is 3-4 millimeter in the first layer, the diameter of the electrode can be increased and the lateral swing will be increased in the future. The arc should be right to the weld pool to avoid a side of the groove metal and the electrode along the weld center. At the same speed, it moves in the direction of welding to prevent the liquid metal and slag flowing into the weld pool to produce the welding. The action should be quick when replacing the electrode. The arc should be induced on the welded seam of the 10 millimeter of the arc pit when the welding is in high temperature. Then it will return to the original pool and continue to weld after the pool is filled. 3. welding sequence In order to reduce the deformation of the welded joint, the length of the weld gap is within 500 millimeters, and the direct welding method from one end to the other end can be used, if the length of the weld is more than 500 millimeters, and can be welded from the center to the two ends. 4. welding current and electrode diameter The diameter and welding current of the welding rod should be selected according to the thickness of the welding piece, the beginning of the weld, the outer profile of the weld and the heat dissipation, and so on. Usually, the welding current is 40-50 times the diameter of the welding rod.