The business end of the MIG welder is called a gun. Filler wire and shielding gas is fed out of the end of the gun.
The business end of the MIG welder is called a gun. Filler wire and shielding gas is fed o
A few years ago on 60 Minutes Jesse James said, "There are two kinds of people in the world, those that can weld and those that can't." You see it every week on cable TV, a fabricator shapes a piece of metal or a couple pieces of metal and then pulls out a MIG or TIG welder, tacks the parts together, and then runs a bead fusing the two pieces together permanently-well hopefully. When they're done it's another perfect part. They make it look easy and after welding bits and pieces of metal together a masterpiece emerges. Can the home hobbyist/enthusiast do the same level of fabrication? Possibly, with the right tools and training almost anyone can create or repair anything. But where do you start? There is a lot to learn, but it's not as daunting as you may think. It does take time and effort though.
A midsized MIG welder from Lincoln Electric that can be adapted to weld aluminum.
What Is Welding?
According to the American Welding Society (AWS), welding is a material joining process which produces coalescence (joining together to form one mass) of materials by heating them to suitable temperatures with or without the application of pressure or by the application of pressure alone and with or without the use of filler (metal added in the welding process) material.
Basically pieces of metal, the base metal, are fixed into position. Heat is applied to melt both pieces of base metal creating the puddle. The welder moves the heat source along the joint continuously melting the base metal and fusing the parts together. In most welding processes, filler metal is added, this replaces the base metal used in the puddle and increases joint strength. Filler metal when properly added to the puddle creates the weld bead.
TIG welders use a torch to hold the electrode. This one is water-cooled.
Welding Processes
Welding processes fall into several general groups, such as arc welding, brazing, oxyfuel gas welding, resistance welding, and solid state welding. And within these groups are more specific processes, such as gas metal arc, plasma arc, dip brazing, pressure gas welding, percussion welding, friction welding, and many more.
However, walk into any motorcycle shop and the majority of the time you'll see a Metal Inert Gas (MIG) welder or Tungsten Inert Gas (TIG) welder close by. MIG and TIG both fall into the general arc-welding group. Arc welding utilizes the combination of an electrode and a welding power supply creating a direct or alternating current to create an arc between the electrode and base materials. The arc generates the heat to fuse the base materials together. For the home shop/do-it-yourselfer, both MIG and TIG welders are available to connect to your household 115V outlet, but with these machines the thickness of material that can be welded in a single pass will be limited due to their lower power output. However, if your shop or garage is wired for 230, you'll be able to increase your welding capabilities/materials thickness.
All of the welding processes require some type of shielding to protect the weld puddle from atmospheric contamination. One type of contamination is hydrogen embrittlement, in which the welded material becomes brittle and can severely weaken or fracture the weld due to exposure to hydrogen.
Shielding is done several ways, two of the most common are flux and gas. Flux is applied to the filler rod before welding or it's a coating on the filler rod. There are also paste fluxes that are applied to the base metal. Shielding gas is an inert (nonreactive) gas that is flooded around the weld puddle to protect it. Both MIG and TIG use shielding gas.
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Adequate for professional use in light fabrication, the Auto-Set function on this Millermatic 212 Auto-Set MIG welder (approximately $2,000) appeals to beginning welders because it takes the fear out of machine setup. You just set the welding wire size and material thickness and Auto-Set selects the optimal wire feed speed and voltage.
Adequate for professional use in light fabrication, the Auto-Set function on this Millerma
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With fewer controls to deal with than most TIG welders, the Diversion 165 ($1,617) from Miller is not only easier to set up but priced right for beginners. it also comes with Welding for Dummies and a DVD on how to set up and operate the machine, along with some basic TIG welding tips.
With fewer controls to deal with than most TIG welders, the Diversion 165 ($1,617) from Mi