Welding Aluminum With a Stick Welder? Part 1
Well, is it possible? I get this question all the time. The short answer is yes, but it is also one that deserves a bit of qualification. So, here it goes:
There is a pecking order of methods of preferred welding aluminum. The best process for the highest quality results is typically recognized as TIG. But that being said, MIG works fairly well on thicker materials with a fairly smooth result. It is also much more rapid, and welds from MIG can almost equal the quality of TIG welds, depending on a few factors.
Stick welding aluminum on the other hand is a small, and largely unrecognized method for welding aluminum. It is also a very expensive alternative to welding aluminum. A pound of aluminum electrodes cost about 20-30 dollars. Unfortunately, most of the time, the smallest quantities available are in 5 lb increments. Spending one hundred bucks for a 5 minute aluminum repair is not an option.
Another issue is that the welding rods that are used for welding aluminum typically are hydroscopic, which means that they have an affinity for water and if left out, almost overnight the flux will become damp and gummy. It is also not an option for thin materials, as welding with aluminum welding rods isn’t generally recommended under about 1/8”. It also can only be used with DC stick welders, and not AC.
Reverse polarity (EP) is used, which is the same most other electrodes in steel or stainless. But the biggest issue is that it is a fast process, borderlining on mach 1 or so it will seem to you at first. The aluminum melts rapidly so rapid forward motion and intense concentration is required to lay a suitable bead.