Metal Welding Techniques
Welding, the process of joining metals with the use of heat and electricity, encompasses a variety of techniques. The type of metal and the requirements of the weld determine which technique is used. Like many skills, proficiency in welding is learned in progressive steps of increasing difficulty. Simple stick welding is fairly easy to learn, but more advanced techniques require practice, patience and the right equipment. Does this Spark an idea?
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About Metal Welding
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Most welding is done on steel, though aluminum, copper and other metals can also be welded. Some types of welding require the use of gases that remove impurities from the weld area for a solid weld with a refined appearance. Electrodes and welding wire is used to melt the metal surfaces and provide joint material for the weld. Always wear a welding helmet with darkening glass, gloves, protective clothing and heavy shoes when performing welding operations.
Stick Welding
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Stick welding, also called Shielded Metal Arc Welding, is the simplest type of welding to learn. Stick welding is forgiving of dirty or greasy surfaces. Selecting the right amperage for the metal's thickness is important, according to the Millerwelds website. The arc length should not exceed the thickness of the material. Holding the electrode too close to material will decrease the amperage. The rod should be held perpendicular to the surface with the top of the electrode held at a 5 to 15-degree angle as it is dragged across the material. Adjust the travel speed to keep the electrode at the leading one-third of the weld pool.
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MIG Welding
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Cleaning the metal before actual welding operations begin is required with Metal Inert Gas (MIG) Welding. A grinder will remove rust or paint, and solvents or plain detergent and water will remove grease. Hold the torch so that you have a good view of the weld pool, and angle the torch at a 20-degree angle. The torch should not touch the metal. A zigzag or weaving motion ensures that both surfaces of metal receive the weld. Push the torch along rather than pull it to achieve the right coverage of shielding gas.
TIG Welding
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Tungsten Inert Gas (TIG) Welding uses tungsten rod to make a neat, refined weld that looks good on metal surfaces that are highly visible. Clean the metal thoroughly before welding. Use the smallest electrode to do the weld to prevent erratic arcs and weld contamination, according to University of California writer Tom Bell. Different arc lengths are used for different materials. Strive for a straight, even weld with the shortest arc length required.
Resistance Welding
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A different type of equipment that heats the metal at a fine point to join very thin materials is required with resistance welding. These machines require different sizes of electrodes for increasingly thinner pieces of steel. The current is applied quickly onto two pieces of metal to join them together at strategic points. These small welds are then refined and the part finished for a good appearance.
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References
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