Aluminum welding - yuk!

[Darrell C]

Long post, but here's the story. For several years I've been using a Lincoln Weld-Pak 100, converted to MIG (CO2/Argon mix). Yes, it's small, but I found it forced me to get good at welding in order to get good results out of that little unit. Not to toot my horn, but I've gotten good at running beads: horizontal, vertical, and even upside down (those are tougher, but I've been practicing).

Now, I purchased the Aluminum kit, which swapped out the guide tubes, drive roll, gun liner, and contact tip. Fed the .035 Al wire through, hooked up the pure Argon tank, and began to have at it.

Wow, talk about lousy welds.

First off, I started by setting the heat and wire speeds at the settings I used for steel. Struck the arc, and the entire amount of stick-out immediately vaporized ( I watched it melt right back up to the gun tip) and I lost the arc.

Gradually increased wire speeds until I could hold an arc, and ended up with wire speed about double what I used when welding steel. This resulted in large beads, but poor penetration. Turned down the wire speed until I could just barely hold an arc, got moderate penetration (my arm movement was critical), but still very large bead size (due to wire speed).

Decided to take a break, and thought I'd ask some folks here who are good at welding: What's up?

Is welding Al really that much harder and less forgiving?

Do I need more heat, which chances are will mean more wire speed?

Other comments welcome...

[Allen]

Aluminum takes much more heat than steel.

More heat. Less speed.

Allen