Hi
I only bought helium to try the MIG function on my welder. Helium is normally used on stinless steel because of the higher arc temperature. It can be used for Aluminium with DC, aluminium is normally welded with argon or argon 30% helium. welding aluminium with you have to have the ceorrect electrode. The recomended one is WZ08 8% zirconated tungston, Stainless steel the tungston electrode has 2% thorium. In the UK helium is super expensive compared to the other gasses.
With aluminium you really need, AC the welder I used to use was square wave AC set to 70% 30% positive negative ratio. That gives opptimum cleaning to penetration. Because it didn't have a pedal with it there were more controls on the front than the space station, ramp up current, ramp down current, pre flow and post flow shielding gas pos neg ratio, plus several others. With a DC welder buy yourself a spool gun and using argon MIG weld your aluminium.
I have a gassles mig and after using it for the first time I bought two tins of antispatter and I have a tub of nozzle shield on order. That is why I bought the new gas MIG.
Finally if your welder doesn,t come with a TIG torch you need to buy one with a gas valve on the torch. Don't be tempted to try CO2 on your TIG unit or argon CO2 mix the electrode will very quickly burn back, and no CO2 on aluminium it doesn't work and the weld goes black.
Brian