Welding Aluminum - Questions/Tips

[LMH]

Hey all
I've been fooling around with welding aluminum w/o much good result. I wondered if someone could give me a couple tips on what I'm doing wrong.
I do have a fair amount of experience welding but I haven't tried welding aluminum since high school. And then, it was using a TIG welder.
And that was a LONG time a ago!

I am using my Lincoln MIG, converted to the aluminum set up but not a spool gun. It has Argon gas and .030 filler. I'm running about 25 SCFH of Argon.
The aluminum is cleaned with a stainless pad.

What's happening is the filler burns before contacting the surface, balls up and falls to the surface. I've tried faster wire speed but it then burns through. More amperage, less amperage, more gas, less gas. If I increase the wire speed and the amperage way up, I can get a bead going but it burns through after about an inch. I'm moving it along (pushing) fairly fast as compared to welding steel, so I don't think that's the issue.

Any ideas?

Larry