How to polish machined raw aluminum?

[makoshark]

What exactly are you working on? The first thing I noticed you are doing wrong is you used paper below 400 grit. Aluminum is soft and doesn't need anything softer than that. Are you wet sanding or dry sanding? If your dry sanding, then stop doing that and start wet sanding it. Also, your not going to be able achieve a good shine with just a drill. You need a dedicated buffer or converted bench grinder using Tripoli compound and a spiral buffing wheel. I would start back over and wet sand it with 400 till I saw nothing but the 400 grit scratches and then work my way up to either 800 or 1000. You could actually stop around 600 if you have a good buffing machine. The Tripoli compound will remove a lot of scratches. You can follow that up, for color, with some white rouge and a soft buffing wheel or Mother's Billet polish