[bake]

Wow, A lot of confusion about welding here. MIG (GMAW) and TIG (GTAW) are not related at all except that they use an electric Arc. For your application with your welder a spool gun would probably be the best bet for Aluminum MIG. It is difficult(but not impossible) to push the soft aluminum wire through the liner. Argon is the correct shielding gas. The filler wire will have to match the material being welded. Cleaning is the key to Aluminum. The oxidation that forms on Aluminum has a higher melting point than the Material itself. Wipe parts clean with Acetone. SS wire brush to remove oxidation. MIG Aluminum is difficult but can be done. If you have any specific welding questions I can probably steer you in the right direction.