MIG welding TIPS and tricks - part 3
Getting the most out of your MIG welder is important, not only for performance but also versatility. While many people consider TIG to be the gold standard for Aluminum welding, a DC MIG welder really does offer a good compromise while welding aluminum. It can rapidly handle all but the thinnest materials. Usually, for a MIG without pulse, this is 1/8” or over in thickness. Most Aluminum welding with a MIG welder is performed with a spool gun or a push pull gun, combined with 100% argon shielding gas. This is done in the spray arc range. So when purchasing a MIG welder, always consider the cost of the spool gun or push pull gun into the budget if you think you might ever want to weld aluminum. The speed is much faster, and when done properly, quality is good. Practice will be required of course, as it is somewhat different than short circuit MIG welding. But if you don’t have a spool gun and find yourself needing to weld aluminum, don’t despair. MIG welding of aluminum can be performed with a little practice using the standard gun. First, you’ll need to use at least .035” wire, with 5356 series wire being the preferred choice due to its stiffness and resistance to bird’s nesting. 4043 is too soft and will create feeding. You also need to source a Teflon liner, or at least a liner material designated for aluminum welding. Using a short gun, (usually the stock gun on Everlast MIG units is sufficient) held straight out as possible without coiling or heavy drooping the wire will feed well with the optional U groove feed rollers. Also it should be mentioned that feeding issues will be greatly reduced if you use a special aluminum tip or the standard tip with a one or two sizes larger orifice to accommodate the extra expansion space needed for aluminum wire. This will help prevent sticking of the wire in the contact tip and any associated bird’s nesting that may be caused.