I am posting on how to sand and polish Aluminum It is not hard to do but very time consumeing Please keep in mind I am posting as a how to with the worse case possible! Most items will be way easyer since they start out with a better suface I first cleaned the parts in a parts washer with mineral spirts so they would be free of dirt and oil. Next step is to get rid of casting flash, like i said this part is ruff and not the norm. So it will take the extra mile to get it right. Normaly this step could be by passed! But since we are dealing with a casting being so ruff, We are going to take no prisoners I started getting the casting flash with a plain ole metal file since it would have just wasted sand paper and tolk a ton of time as well. Once that was filed down, the part was sanded with coarse sand paper progressing to finer grits to remove the scratches from the corser [a[er used before. It is very important that the sctraches from the privous grit are removed before going to the next step finer! So I went from metal file then #80/180/360/600 grit papers were used, I used my DA and my trustly Die grinder with paper rolls, in the smaller tight areas. One thing that will come in handy is a cheap candle. Hit the paper roll on the wax and it will lube the paper and realy extend the life of it. Once everything is sanded you are then moving into polishing mode! This is realy just like sanding you will start with a agresive compound working towards fine ones. I get the smaller tight areas first with "Cone shape buffs" The smaller buffs are used in the die grinder and small air drill for larger cone buffs. The compounds used are grease based so when touched to a buff they melt and go into the buff. Working first with Black Emery, then Gray emery, at this point you have a nice shiney part but it does not have depth! So the iuse of white rouge is used to get the depth/color. Note buffs must be changed for each compound used,do not use the same buff. Once all those areas are done we move onto the large buffer wheels. Doing the same thing Black, Gray and White Rouge they do have a even finer compound that is blue. Now you have a part that is eone but needs to be cleaned to get the residue off so By hand clean it with Wenol and clean white rags.