i don't do aluminum, i hate aluminum, now, i have to do aluminum.

i owe someone a big favor and this is what they ask of me. oh well. anyway, my machine is a miller shopmate multi-process. good machine but, it's only dc. as much as i don't like it, i have been known to tig aluminum but, not with my machine. the one i used in the past is shorting out somewhere and you can't keep an arc.
i tried brazing it with a tig rod and that didn't work. my boss thinks that i didn' have it hot enough. now, someone said that you can stick weld aluminum with DCEP.

there is my problem, now here is my question. can anyone give me some helpful pointers doing it either way? if i try brazing it again, do i need flux? if i stick weld it, do i run 90 amps or115? do i drag the rod or work it? what kind of angle on the rod? should i pre-heat, post-heat, or both? with it being cast it is verry pourous ,will that help me or hurt me?