Using a Spot Welder

Posted: May 19, 2014 By: Louis Beaudreau

A spot welder helps you connect two pieces of metal together at a specific, circular point, which is very ideal for a lot of auto body work. Using an electric arc, spot welding essentially melts a top sheet of metal to fuse with a bottom sheet, making it a great way to connect body panels and make repairs. Below, we take a look at how to use a spot welder in order to make these types of welds.

Step #1: Preparing to Weld

The first thing to understand is that the best way to learn how to properly use a spot welder is to practice. Welding is not a terribly difficult task, but it does take practicing on scrap metal multiple times in order to be able to make a professional-grade weld. When you’re using a spot weld gun, you need to get it ready to weld metal and assemble it in the correct fashion.

First, select the proper welding head and install it on the gun. For spot welding on a flat surface, select a four-pronged flat head and simply twist it onto the end of the gun torch. Two-pronged heads, if they’re not flattened on the ends, are best for welding corners and other curved metal areas. Next, load the electrode into the tube on the front of the gun, and lightly tighten the set screw. Push the electrode into the tube until the tip of it is even with the ends of the welding head prongs. Now, connect the gun to your arc welder. Insert the end of the welding gun’s power cable into the welder’s electrode holder, making sure that the metal pin on the end of the power cable establishes a solid connection. Finally, connect the welder’s ground clamp as close as possible to your metal workpiece. Now you can begin welding.

Step #2: Making a Spot Weld

Before making your weld, make sure that your welder is set between 40 and 60 amps. Starting out at 40 amps and turning it up as needed is recommended for beginners. Always make sure to wear protective gloves and a quality welding helmet with a number 11 lens while you are making the weld. To make a spot weld, pull the trigger completely back, and firmly press the welding head tongs against your metal pieces at a flat, 90 degree angle. Slowly release the trigger until the welding electrode makes contact with the top sheet of metal. The current should begin to flow immediately on contact and will create an electric arc between the electrode and the metal piece. The top layer should crackle lightly, then melt into the bottom layer for a fully penetrative weld. Once the top layer starts to create a puddle, pull the trigger all the way up again to break the electric arc. Now, you can move on to the next spot weld.

It is important to let the spot weld gun cool after about every 10 to 12 spot welds that you make. These guns can get very hot and at times overheat, so it is important to give them a little break. Successfully making spot welds this way will render very durable welds as long as you make sure to create that puddle on the top metal piece, which melts into the bottom one, then lift the electrode from the surface to cool it off. Keep practicing your welds, and always be safe when using a spot welder.

To learn more about spot welding and for more DIY car tutorials, be sure to visit Eastwood.com.

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