Other Forms Of Welding You've Never Heard Of. Part 2
Resistance welding (RW) has been around for a long time. Resistance welding is performed by using heat, pressure and low voltage current. Two pieces of metal are pressed together firmly together with two high pressure cylinders with electrodes attached to the ends. The parts are heated until they are soft and pliable, but not quite molten. The pressure forces them together, and no actual melting of the metal has to take place. This is not unlike old fashioned forge welding where two pieces were heated red hot, then hammered (forced) together. It’s definitely a lot higher tech but the principle is similar. One advantage of RW is that the weld needs no flux or shielding gas, because no air is present at the site of the weld because the two pieces are in direct contact with each other under pressure. The welder itself is usually a capacitive type welder or a transformer welder that operates at an high amperage. This type weld is usually automated and is controlled through an electronic control system. This basic welding process can be modified to be used as a spot welder, projection welder, or even a percussion welder. Because of the basic simplicity of the process, little skill is required, other than to operate the basic electronic controls. It’s likely that you’ll never need to operate a resistance welder, but you will find resistance welding employed in many everyday metal items you find in your home or place of work.