ER70S-6—ER70S-6 rods are good for welding dirty, oily, and rusty steel. You can also use them to join misaligned pieces together. They create X-ray quality welds without air pockets for a smoother and more uniform welding bead than standard welding rods. Their high silicon content allows them to flow easily when melted, so they spread out to fill in the space between two pieces of your weld before hardening.