How Spot Welding Works

Spot welding is a practice utilized in many different mechanical industries that helps you weld two pieces of metal together at a specific point. Below, we take a look at how this process works and also how you can use simple MIG and TIG welders to create your own professional-grade spot welds.

What is Spot Welding?

Spot welding is the process of joining two pieces of metal together in separate, circular points through the process of conductive heating. Spot welding is the best way to permanently attach two particular types of sheet metal, welded wire mesh or simple wire mesh together at a particular point or points. In the auto industry, spot welding is primarily used to weld together pieces of sheet metal that form the body of a vehicle.

In spot welding, the heat is obtained through an electrical current. Traditionally, the process of spot welding uses two copper alloy electrodes that simultaneously clamp two pieces of thin metal together and focus them in a small circular “spot.” When a large current of electricity is forced through the electrodes, the energy is strong and concentrated enough to melt the metal at that spot and form a weld. This type of welding eliminates the need for metal weld material to be created and applied in order to join two pieces of metal together. Plus, spot welding delivers a large amount of energy in such a short time that it permits the welding to occur without excessively heating the remainder of the metal pieces. Spot welding is used to produce welds that are impenetrable, reliable and very long lasting.

Learning to Spot Weld

There are specific kinds of welders, aptly named “spot welders,” that are commonly used for spot welding, but you can also use a MIG or TIG arc welder to perform spot welds if you have the right attachments. In fact, Eastwood sells its own MIG and TIG Spot Weld Kits that contain a special nozzle that screws right into the top of your welder torch. The spot weld nozzle screws onto your MIG welder just like the regular nozzle does except that the spot weld nozzle has two extensions on the tip that allow you the perfect distance between your welder and the surface of the metal that you are welding. Eastwood’s spot welding kits also come with a pair of spot weld pliers keep both surfaces of metal together by clamping down and locking in place.

To make a clean spot weld using one of these MIG or TIG kits, attach the spot weld nozzle to either your TIG or MIG welder, and use your clamp to secure the two different metal panels together. Make sure the half-circle cutout of the clamp is positioned on the part of the metal you intend to weld. Now, slide your welder’s spot weld nozzle into the clamp cutout, and make sure the nozzle’s extensions are flat against the surface of the metal. Now, weld both panels in that spot for about two to three seconds, depending on the gauge of metal. The result will be a clean, full penetration weld on both sides of the metal.

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