ER70S-6—ER70S-6 wire is good for welding dirty, oily, and rusty steel. You can also use it to join misaligned pieces together. It creates X-ray quality welds without air pockets for a smoother and more uniform welding bead than standard welding wire. Its high silicon content allows it to flow easily when melted, so it spreads out to fill in the space between two pieces of your weld before hardening.