Trouble Mig welding aluminum

[RGalyon]

Hi, I posted this on Welding Web, figured I'd post here as well, get some differing opinions. Trying to mig aluminum and the welds look like rabbit turds. Machine is a MM211 with spoolmate 100, set per manual at 5/70. Wire is Harris 4043 .030. Argon is set at 19cfh. Material is 1/8 thick, gapped at 1/8, brushed and wiped with acetone.IMG00857-20120531-2021.jpgIMG00856-20120531-2017.jpgIMG00858-20120531-2021.jpg

[H80N]

ARE YOU SURE THAT YOU ARE USING 100PERCENT Argon??? and not a mix like 75/25 like you would use for mild steel??

You may be drawing boiling off and drawing in impurities and crud into the weld area from the bench surface... try to fixture it so it is in free air and not in direct contact with the bench...
and
Clean your area to be welded with something like a clean stainless steel scratch brush to break through the oxide layer...

[MMW]

Looks like a gas problem. If you are using straight argon turn it up in the 25-30 range. Make sure you have no breeze or fan blowing. Push the gun with about 1/2" stickout. Can you here the gas when you trigger it?

[RGalyon]

Thanks for the replies, I am using 100% argon, same tank I tig with. I hear gas when the trigger is depressed. Stickout is 1/2-3/4 and material was brushed and cleaned with acetone. When I first got it hooked up, it ran a beautiful bead. Then they went to sh*t.

[RGalyon]

I just swapped my machine over to the regular gun and the gas back to the mix and ran some beads on steel. They came out fine, so if there is a gas flow problem I wouldn't think its the 211

[H80N]

How about your fixturing???

You may be drawing boiling off and drawing in impurities and crud into the weld area from the bench surface... try to fixture it so it is in free air and not in direct contact with the bench...

Aluminum is pretty sensitive to smoke and impurities...

[corbyndad]

Run some beads out away from the joint and see how it does.

[RGalyon]

I moved the gap out off the bench and attached the ground directly to the material, and kicked the gas up to 30cfh. Looks better. Lots of soot, is that normal?

[Broccoli1]

I moved the gap out off the bench and attached the ground directly to the material, and kicked the gas up to 30cfh. Looks better. Lots of soot, is that normal?

Soot is normal when Mig welding AL

You can tweak it a bit more but I get the same thing with my MM211

The Passport didn't produce as much soot, same spool gun

[H80N]

I moved the gap out off the bench and attached the ground directly to the material, and kicked the gas up to 30cfh. Looks better. Lots of soot, is that normal?

AHA!!! looks a thousand percent better... the bead looks fine... little soot on the edges won't hurt...