I have an old stick welder (or as it is officially known "shielded metal arc welding (SMAW)"), it is AC only. DC is better for welding steel if you can get it. I use the stick welder for thicker stuff as I am sure to get good penetration. Use 6011 rod typically, it is an all position rod as well. 7018 won't run on AC unless you get special 7018-AC rods. As stated, most low hydrogen rods are intended for DC. I don't need anything rated stronger than 60,000 psi tensile strength, so the 60xx rods work just fine for me and run nice on AC.