When welding with a wire feed what are the differences between welding steel and aluminum.

What I want to know is the method. Can you weld aluminum the same way as steel?

I know the major differences that need to be with the machine, shield gas, wire etc..


Edit: What I am basically asking is can I pick up a wire feed machine setup for running aluminum and lay down a weld that looks the same as i could with steel?

A few issues come up when MIG welding aluminum that don't when welding steel. The wire alloy should be matched to the alloy being welded but 4043 is the most widely used. It is quite soft stuff so feeding .035 diameter 4043 through a MIG gun is like trying to shove a cooked noodle up a wildcat's butt. The gun should be relatively straight and short. Minimum drive roll tension helps. Keep a lot of spare contact tips around as you will burn-back often. Try to always point the gun in the direction of travel as this will keep the solidified portion of the weld cleaner. Preheat, if you can, anything thicker than 1/4". Pure argon at normal (30-35cfh) flow. Some people/machine combinations work quite well while others are quite frustrating. Alloy 5356 wire is harder and easier to feed but the welds are hotter and a bit "dirtier". All I can add is keep trying and good luck!

in my machine you have to change polarity (i use a millermatic 130 ) and i have allways used the upper heat ranges