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The Basics of Welding, Part 3
Practice! Now that you’ve learned the basics of welding in the previous two articles, on to the welding! One does not need to be a metallurgist to understand welding, but the basic metal properties need to be known. The first step to welding is to decide what metal and what type of weld to perform. For the purpose of this article, the weld will be a lap weld and the metal will be steel plate. The welding machine will be a mig welder with an inert gas. Although varied thicknesses of metal can be welded together, keeping the same thickness yields a better result. Use eighth inch steel plate as the practice material.
Two pieces of scrap eighth inch steel are cut into four inch by four inch squares. The metal must be prepared before attempting the weld. A small angle grinder can be used with a wire brush, flap disk or abrasive stripper. Clean the metal until it is bare and generally oil free. Using vice grips or welding clamps, clamp the two pieces together with about a two inch over hang.
It is very important to adjust the welding machine settings, such as heat and space, before you start welding. Most welding machines have a chart inside the wire spool flap that gives adjustments to the varied thicknesses of metal. Remember a good weld will have good penetration. If the heat is too high, the weld will burn through the metal. If the heat is too low there will not be enough penetration and the weld will break. Speed will control the flow of the metal. Slow speed can create gaps in the weld. High speeds will create puddles of weld. It is all a matter of trial and error. Mess with the settings until the best weld is created.
The welding machine has a ground clamp and an Argon/Co2 mix regulator. Attach the ground clamp to the metal which can be supported in a vise. Open the Argon/Co2 mix regulator. Make sure to wear protective clothing like leather gloves and a welding apron. Most importantly, a welding mask has to be worn to shield a person’s eyes. Flash burn is a common problem with welders that choose to weld with no mask. Permanent eye damage can come from this! Place the welding gun to the area that is being welded. Hold the tip about a half inch away from the metal joint. Flip the mask down and press the trigger!
Do not push the gun to contact the metal directly; let the wire come out of the gun. Continue to hold that half inch gap from the steel. To create a tack weld, move in a short circle and stop after about two seconds of welding. This will form a small dot of weld on the metal, and now the two pieces of steel are fused together. To create a bead of weld do exactly the same and continue to form a line of circles. Overlap the next circle while moving down the joint to create one continuous bead. Through the mask the metal will look molten or as if the edge is burned off the steel plate. It’s pretty amazing that one can see the metal fusing together.