A stitch welder is a great tool for welding substantial pieces of sheet metal together, typically to form automotive body panels. In order to do this properly, it is important that you learn how to lay a weld bead with your stitch welder onto the surface you are welding to ensure a good, strong fusion. Below, we take a look at how to best lay a bead using a stitch welder.
Step #1: Preparation
Before using your stitch welder, it is important to make sure that the tool is properly hooked up and adjusted. Have some scrap metal securely in your work space to use as practice before you use the welder for any permanent project. Clamp the workpiece firmly to a non-flammable surface, and securely hook up your ground connection. Now, put on your safety gloves and welder’s helmet with the lens cover temporarily raised to protect both your face and hands while welding.
Next, insert a fresh, new electrode inside the stitch welder, and snug up the set screw. Line up the electrode about an inch above your workpiece, keep it steady, lower your welding helmet lens cover, and strike an arc. It will be difficult, at first, to strike an arc while looking through a very dark welding helmet, but that is what your practice metal scrap is there for. Remember, if you move the end of the rod too fast along the material, the arc won’t be created, and if it moves too slow, the rod will stick to the workpiece. If your rod becomes stuck, simply wiggle the rod gently with your stitch welder until it becomes free. If a rod becomes sullied or unusable, feel free to insert a new one into the welder instead. Continue practicing your weld, making sure to feel for the right angle and momentum of the rod traveling against the metal surface. Once the rod sparks, lift it up slightly and create your arc.
Step #2: Laying the Weld Bead
Once you have struck your arc with the stitch welder, the rod will carry the arc as you move the welder along the metal joint being welded. The rod must be fed onto the workpiece at the same rate the arc is consuming the rod, so both time and coordination are key. If you move the welder too fast along a line, the weld bead that is created is light and narrow, and it will barely penetrate the way it needs to to create a quality weld. When you’re starting out using a stitch welder, don’t try any complicated circular or criss-cross patterns. Practice getting the straight line movement and timing just right to achieve a solid weld bead. Watch the area where the rod has been, not the actual arc itself. The bead, consisting of the molten puddle of metal, should be observed to see how much the weld is penetrative, light, hot, cool, wide, narrow, shallow, deep, etc. Studying this will help you learn and improve your technique for the future.
One method that a number of welders do is use the “one step forward, half step backward” motion. In other words, if you move the rod a quarter of an inch down your workpiece, you move the rod back up an eighth of an inch to create overlapping layers (shingles), which can strengthen each little section of the bead. Once you make a few beads, chip off the slag with a hard wire brush, being careful to protect your eyes from flying, razor-sharp bits, and inspect each bead closely. The key to making great weld beads with a stitch welder is continued practice. A good way to practice would be to draw out straight lines on a piece of scrap metal about a half an inch apart from one another and try making weld beads that follow the lines exactly. The more you gain experience with a stitch welder, the better you will be at laying beads.
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