The beginning of welding practice will start with the arc first. The arc is the distance between the tip of the welding wire and the work metal surface. This is a good distance to allow the arc to continue There are two methods of arc initiation: the ticking method and the tapping method.
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The scratching method is forcing the wire to come into contact with the work metal by scratching it next to it until an arc is formed. Then lift the wire up slightly until the desired arc distance is about 1/8 inch.
Knocking method is forcing the wire to be inserted vertically until it touches the work metal and then lifts it up and down. until an arc occurs as required
Position and posture of electric welding
- The connection is stranded in a flat position. Landing connection is a type of joint that is widely used in industrial applications. Don’t waste time preparing for work. The overlap joint has the highest strength when welding the seam on both sides. In welding you must not use too high current. The angle of the welding wire during welding is about 45 – 60 degrees. The movement of the wire will be forward and backward along the welding line. This movement of the welding wire preheats the work metal before it can be welded. This will complete the convex weld. and prevent molten slac from flowing beyond the weld.
- Connecting butt joints Flat butt joints are the most commonly used joints for general metal jointing. Metal work that is over ¼ inch thick when welded both ends is a very effective seam. The strength of the weld is more or less depending on the size of the penetration depth of the weld. The depth of penetration depends on the size of the wire and the current used for welding. For applications with a thickness of 3/16 in. when only one side is welded. The seams are always spaced. Butt weld seam welding must adjust the current to suit the welding wire. While welding, the wire must be tilted forward 10 – 20 degrees in the direction of the wire moving.
- Connecting a T-shaped joint in a flat position T-shaped butt welding The current must be adjusted high enough to allow the molten metal to flow easily. to cause deep penetration down to the bottom of the joint forcing the welding wire to the corner of the joint It must be pointed on the metal stand rather than the bed sheet. Along with tilting the welding wire forward about 30 – 40 degrees, try to move the welding wire at a consistent speed. And there is a short forward backward. To warm the bottom part of the joint It also prevents molten slag from lagging behind the welds.
- Welding in parallel position Welding of various joints in a horizontal position, forcing wires to be welded. The welding wire must be forced to point upward at a 20 degree angle to apply the thrust of the arc. Help support the molten metal in the basin to flow down and flow back up to the weld. In addition, the wire must be tilted at an angle of 20 degrees in the direction of movement of the wire. as well as welding in a flat position
- Welding in the standing position This type of welding exercises can be divided into two methods: Up Hill and Down Hill. An important technique is to force the welding wire perpendicular to the work surface and tilting the welding wire at an angle of no more than 10 degrees upward. The current adjustment should always be adjusted to have a relatively high current. When welding, the welding wire should be moved in a raised motion. Then lower it down to the molten metal basin about 2 inches, but be careful not to let the arc extinguish.
To connect down, the current must be adjusted to increase. Tilt the welding wire at an angle pointing up about 15-20 degrees and force the wire to be perpendicular to the surface of the work metal. When welding, short arc distances should be used because normally slag will melt before the weld when you see that slack Flow tries to shorten the arc distance. along with increasing speed If that doesn’t work, knock the slack off.
- Overhead welding position It is the most difficult welding position to perform. And it is most dangerous to the operator if the work clothes are not properly worn. The key for overhead welding is: The scaling of the current must be high. and use a short arc distance forcing the wire to be perpendicular to the work surface and an inclination angle of not more than 10 degrees in the direction of the wire moving The movement of the wire will be forward and backward. or oscillating welding wire movement
- Types of welded joints The types of weld joints can be classified on the basis of basic welding joints for new trainees as follows:
– Butt Joint
– Lap Joint
– Corner Joint
– T joint type (T – Joint)
– Edge Joint