[Rasper]

Dave,

You got some first class advice from these guys. All I have to add is to reiterate what they said about one important thing: You absolutely must get all of the scratches out put in by the previous sandpaper, before you move on to a finer grit. In other words, with the 80 grit you have to sand it until all that is left in the aluminum are 80 grit scratches, no file marks, no dents, no gouges. If you move up a grit before you do this, you will never get them out. At the next level, let's say 150 grit, you must sand out every single 80 grit scratch, every last one, before you move up to say 240. The other thing about this process is: it takes a whole lot more sanding than you think it will: two or three times as much, or more. You will think you got those 80 grit scratches out with the 150, but you haven't. I have learned this the hard way. I can't tell you how many times I have gone all the way through 240, 400, 600, 800, and gone to the polishing wheel, only to realize I still had 80 grit scratches in the piece, and had to go back and start with the 150 again. The result is worth it. Don't settle for second rate. Good luck.

Richard