Mainly for messy, uneven welds, but it's also great for using the gas you would use for flash butt welding without wasting hot spatter getting into your shoes or smoking slag that you get from gasless flux. cored wire. Best of all, you don't have to worry about accidentally fusing two pieces of metal together so you can't separate them. Heck, when you're done, you won't even know they're the same parts.