If your TIG welder has an AC option then you’re all set to weld aluminum, nothing to buy but filler metal.
I weld a lot of aluminum wth the TIG, the puddle acts a little funny compared to steel but it welds easy enough.
A spool gun would allow aluminum welding with MIG, they can be expensive.
I’ve never tried one, hear it’s easy, point and shoot, but may be hard to get a consistently strong weld, takes fiddling with settings.
