How to Spot Weld
Welding is an important component of metalworking and machining operations. There are many ways to join metals together, but welding is very convenient especially if you plan to permanently join two or more pieces of metal together. Here’s how you could spot weld two metal pieces together.
How Welding Works
There are many ways to join metal pieces, like using screws or bolts. Screws and bolts are useful for metals that should move, or are joined together semi-permanently. For metals that do need to be joined permanently, though, you have to weld the pieces of metal together.
Welding works by melting the metal parts and joining them together before the molten parts harden. The weld between two joined pieces of metal represents the weakest point of the structure, and an improperly welded metal piece may actually result in the whole metal structure being completely weakened. A full seam weld may seem to look like the strongest way to join metal pieces, but it is actually the weakest. Spot welding, however, does not weaken the structural integrity of metal as much as seam welding does.
Tools and Materials
Here are some important things you have to know about spot welders and the metal you can spot-weld:
Spot welder. Factories and machine shops use special spot welders that use high-voltage AC current to weld metals together. Two electrodes are attached to a particular spot on the workpiece, and electricity is passed through the electrodes to weld the metals together. Hand-held spot welders are quite expensive, and most factories use large robotic welding machines to spot-weld giant sheets of metal together.
Metal. Spot welding is best for metal sheets less than three millimeters thick, although some specially designed robotic spot welding machines can be used for thicker metal workpieces.
Steps
Wear the proper safety equipment (goggles, welder’s mask, leather apron, leather gloves, long-sleeved shirt, high-topped work boots) before spot welding metal.
Secure the workpiece on the bench with clamps. Do not attempt to weld metal that is not securely held in place on the workbench.
Heat the welding irons and the machine to the prescribed temperature for the kind of metal you’re welding.
Attach the electrodes on the metal and allow the weld to complete.
Disengage the metal from the welding machine and allow the weld to set and cool.
Like any machine and metalworking operation, welding should only be performed by experienced professionals and with the proper tools and safety gear. With these tips, joining pieces of metal together becomes quick, easy, and more permanent than nuts and bolts.