heya there M3THE01!!
Just to add to CUSTOMANDSOUNDs post about rubbing blocks, i recommend ya grab some kerosene and put a bit on the job as you go, it will stop the wet&dry paper loading up (clogging up) with aluminium and scratching the job worse!! Itll also make the paper last a little longer by moving the removed material away form the sanding face
Hope it helped!!
Mark!!
PS: Water in this situation will work ok, but kerosene is the 100% correct cutting medium for aluminium, i do alot of polishing so i buy it in little drums, last me ages and i polish everyday!! See if you can grab a little bottle for a few bucks down the local hardware when ya pop down there next.