What Do You Need. 1  A DC ARC welder that can go as low as 20-25 amps (if yours doesn't you may consider getting a current limiting diode, or get the Stitchwelder that has one) 2  E6018 (aka. farmer rods) or better E7018 1/16 welding rods (which need to be baked before use) 3  Thin sheet metal, 0.021 was what I used.