help with angle iron's

[dbreeze225]

hey guys i didnt do any polishing today i was to busy
i did start sanding a new piece tho
doing this type of sanding i have been doing it by hand
so much effort today i just didnt have the energy can i use a power sander on this type of aluminum
i have a few different types i got the belt sander, and attached to it also has a rotating dis sander.....
also i got a handheld one that doesnt spin you put a square piece on and it vibrates (i dont know the name of this type of sander)
i have been told doing it by hand is alot better i was thinking of maybe doing the lower grits with the power hand held one
then the last 2 (finer grits) by hand ........any suggestions?
i know i am looking for a short cut just wiped out today and it was a thought but i dont know if i should go that route or not i have never sanded this type of metal with power????