well, ME and my dad own a Big Rig detail shop and we polish ALOT of aluminum, Our technique is with out pnumatic air buffer with wool pad with 2in yarn on it. and buff it with a heavy duty compund then polish with aluminum polish (white dimaond, or blue billet) but we always ACID the aluminum before we buff it, it softens up the aluminun to where it cuts better, and thats our way, we did do a 40' aluminum trailer last week and it turned out great! but a horse trailer has alot of small hard to reach places. we started with the Cyclo buffer with the small wool pads on it and some metal polish but it left clouds in it so we went over with the 7in black foam pad and polish and it cleared it back up.