Power/Amps
Setting the correct amperage for any given electrode size or type is important to achieve an ideal bead shape, good penetration, and a minimum of spatter.
• A higher amperage setting results in a flat bead with an excessive amount of spatter, not to mention the possibility of porosity and the electrode becoming greatly overheated.
• An amperage setting that is too low will make striking the arc and maintaining a correct arc length more difficult. Low amperage settings also cause the weld metal to pile up into a rounded bead with excessive overlap and poor penetration. Often the electrode will also stick, or freeze, as the slag will envelop the arc. Amperage settings on the electrode packets are often vague. A 3.2mm general-purpose electrode might have 80–140A indicated on the packet — a big variation. Normally a down-hand fillet weld with a 3.2mm generalpurpose-style rod will be in the vicinity of 120–125A, electrodes for vertical up 105–110A, and for vertical down 120–140A. Every brand is different so take the guesswork out by running the rod on a practice piece first. Buy decent electrodes and you might find you can weld better than you thought.
For example, the Easyarc 6012 and 6013 are fast-solidifying mild-steel electrodes. Great for fast welding on thin and sheet metals. They are also ideal for welding on dirty, rusty, greasy, or painted steel.
Good practice says clean your base material first. No manufacturer’s specs on the packet allow for impurities. If dirt increased the tensile strength of weld metal, everybody would ignore it. But the cleaner the metal the better; it means that the flux won’t have to work so hard.