Mig Welding Aluminum – Tips For Avoiding Problems and Machine Settings

Mig Welding Aluminum is just more difficult than mig welding steel.

Why?  Because everything that can go wrong on Steel, is just magnified when you mig weld aluminum. Even something as simple as the argon flow rate makes a big difference.   A slight tweak of the wire feed speed changes things up big time.  Even a little burr on the copper contact tip can cause the wire feed to slow and burn back to the tip.

So What are 4 of the most important things for Mig Welding Aluminum? 

  1. You need a Spool Gun.  If you are serious about mig welding aluminum and want to avoid frustration, get a spool gun. You cant feed soft aluminum wire very far without having a birds nest.
  2. Push dont Pull.  Always Push the puddle when possible for a cleaner soot free weld.
  3. Use a longer stickout. Mig welding Aluminum uses something called spray transfer. Thats a technical way of saying the wire never really reaches the puddle. So a longer stickout is needed to avoid burnbacks.
  4. Use Argon and not an Argon C02 mix.  Argon or Argon Helium is the ticket.  Dont use argon/c02 unless you just want to do a lot of cussing

Now lets talk about some tips for machine and spool gun settings:

  • You are not going to want to use a mig welder for anything thinner than around 1/8″.  If you are really good at mig welding aluminum, you might be able to weld as thin as .070″. But I am guessing that you are not even reading this if that is the case.
  • For thick aluminum like around 1/4″-5/16″, using 3/64 inch wire and 26-27 Volts and 400-425 ipm  of wire feed speed will work . For thicknesses in between 1/8 and 5/16 , just try using a halfway point like 23 volts and 300 ipm.
  • Start out with wire feed speed setting a bit higher than you think it needs so that you won’t burn tips up.
  • So how do you know ipm? (inches per minute)  Just pull the trigger and count seconds…thousand one , thousand two…until you get to 6. Measure the wire that came out of the gun to the nearest whole inch and add a zero.  That’s your ipm.  For example, if you get 25 inches, that’s 250 ipm.
  • Mig Welder settings like this are a good place to start but since every machine is different, get some scrap and fine tune your settings until you get the results you want. It is so much better to make your mistakes on scrap aluminum.