alloy welding help

[fs1eman]

i have just got my new tig welder .it's perfect on tiging steal .

but when i try to weld alloy i get like a black soot on the weld and don't weld very nice. i have a flow rat of 15 lpm 100 amps and using pure argon .any tips please thanks tony

 

[Paul.]

More information required, what type of welder is it, you will need an AC set for aluminium, what size tungsten, material thickness, filler rods, ceramic size? 15 lpm is too high, I would rarely use any more than 7 or 8lpm for ally, even less in good draft free conditions,
Pictures will help

Moved to the TIG section