Filling in the blanks
Spot and stitch welding controls are a useful tools for controlling deformation caused by overheating during MIG welding. People often mistake these controls for pulse welding, but it is not. Spot welding is pretty clear. The arc stays on for a pre-set amount of time and then goes off. Stitch welding refers to the amount of time between individual spot welds.This is activated by holding the trigger down.
The arc will go on and off automatically, spotting, then resting and then spotting again while the trigger is kept pressed. This may seem strange, but it allows a form of semi-automatic welding that will yield consistent results without warping the metal. One helpful application of this is that you can use this to create a series of small welds on body panels while moving at a continuous speed. This will offer regular spacing between welds, a blank space if you will, while maintaining consistent sized spot welds. Of course you can use it to make a long continuous weld, but offering a break, allowing the metal to cool slightly. This is also quite helpful on long passes where regular repositioning may be needed and can improve productivity with practice.
If you are using to control heat on a body panel, and a continuous weld is required, you can reset the spot stitch timer to go back and perfectly fill in the blank spaces between the welds just as you did on your initial pass. While spot and stitch controls aren’t necessarily a requirement on a MIG welder, they are definitely worth the money if the are available as they are on the Everlast Power iMIG 205.