User manual LINCOLN ELECTRIC AC/DC 225/125

[. . . ] 7 Includes safety, installation, operating instructions and parts lists. Read and understand the following safety highlights. For additional safety information, it is strongly recommended that you purchase a copy of "Safety in Welding & Cutting ANSI Standard Z49. A Free copy of "Arc Welding Safety" booklet E205 is available from the Lincoln Electric Company, 22801 St. [. . . ] Tack the plates at both ends, otherwise the heat will cause the plates to move apart. weld from left to right (if right-handed). Point the electrode down in the crack between the two plates, keeping the electrode slightly tilted in the direction of travel. Watch the molten metal to be sure it distributes itself evenly on both edges and in between the plates. Penetration Unless a weld penetrates close to 100%, a butt weld will be weaker than the material welded together. 4 mm (1/4" In this example, the total weld is only 1/2 (12. 5mm) the thickness of the material; thus the weld is only approximately half as strong as the metal. In this example, the joint has been flame beveled or ground prior to welding so that 100% penetration could be achieved. The weld, if properly made, is as strong or stronger than the original metal. Fillet Welds When welding fillet welds, it is very important to hold the electrode at a 45° angle between the two sides, or the metal will not distribute itself evenly. To make it easy to get the 45° angle, it is best to put the electrode in the holder at a 45° angle, as shown: Put the first bead in the corner with fairly high current. Hold the electrode angle needed to deposit the filler beads as shown putting the final bead against the vertical plate. Welding in the vertical position can be done either vertical-up or vertical-down. Vertical-up is used whenever a large, strong weld is desired. Vertical-down is used primarily on sheet metal for fast, low penetrating welds. Vertical-Up Welding The problem, when welding vertical-up, is to put the molten metal where it is wanted and make it stay there. If too much molten metal is deposited, gravity will pull it downwards and make it "drip. When welding, the electrode should be kept horizontal or pointing slightly upwards. The arc is struck and metal deposited at the bottom of the two pieces to be welded together. Before too much molten metal is deposited, the arc is SLOWLY moved 1/2-3/4" (12. This takes the heat away from the molten puddle, which solidifies. (If the arc is not taken away soon enough, too much metal will be deposited, and it will "drip. [. . . ] Low hydrogen electrodes offer these benefits: outstanding crack resistance, lowest porosity on sulphur bearing steels, and capable of X-ray quality deposits. Thus, they are the first choice when welding "problem" steels. E7018 can be used in all positions, with Motion "C" recommended for the first pass on vertical-up welds. NEVER use a whipping technique or a long arc with these electrodes. [. . . ]