so far with welding aluminum, i have been using 6061, and seems to weld pretty well, however sometimes tough to keep clean. lets discuss the different alloys and why or why not to use them when welding...be it 2024, 5052, 6061, 7075, etc...
because of my curiosity, i found this little gem explaining exactly what i was looking for:
http://www.thefabricator.com/article/aluminumwelding/weldable-and-unweldable-aluminum-alloys
i think that this could be beneficial to be "stickied" for all up and coming fabricators to see and familiarize themselves with aluminum alloys