View Full Version : Aluminum Welding with MIG

09-21-2003, 09:35 PM
I am just learning Aluminun welding with mig.....is it common to have black soot after running a bead, if not what are some possible reasons for it....ie, welder to hot?, Argon setting wrong ( using 25 on flow meter )


09-21-2003, 09:42 PM

There is almost always grease on the Aluminum, the wire, the feed wheels, liner, or from your hands. If you are using anti-spatter gel on the nozzles that is the source. It wipes off - don't worry about it.

The argon prevents the arc from burning the material completely so it decomposes to o2, h2, and c60 (carbon 60 - bucky balls)

[This message has been edited by Thrud (edited 09-21-2003).]

09-21-2003, 09:48 PM
Thanks Thrud

I use a stainless brush for cleaning the Aluminum...was mostly curious if this is natural, or am I doing something wrong...BTW, I hadn't used any anti-splatter with the Aluminum


Forrest Addy
09-21-2003, 09:52 PM
Aluminum has to be welded very clean. Make sure the prep is grease free and freshly scrubbed with a clean stailess steel wire brush to remove the oxide that can form within minutes on aluminum - even between passes

Even vanishly small surface contaminants can affect weld quality and appearance, particularly with MIG. Some people may think I'm over zealous on this subject bacause I'm always harping on the subject. Don't take my word for it. Look up welding specs for airframe pr marine components. Clean workmanship leads to quality and reliability.