Hey, I wanted to sand some of my bumpy cast aluminum parts, like my alternator to a smooth surface. I have a dremel, but my bits are too low of a grit. I'm not quite sure of how to do it, my neighbor polished the "3.4 SFI" on my intake manifold to smooth and it looks really good. I'd ask him, but he's been MIA for quite some time. So should I just find sanding bits for the dremel 800-1000 grit and that should do it? Yes, I know this can potentially take a lot of time.

 

This little kit from Eastwood is perfect for doing the type of job you're wanting to do and it has enough sanding rolls in it to last quite a long time. It has the straight barrel shaped cylinders and also the cone shaped ones to get into tight corners. Once you get up to the 320 grit stage with these rolls you can finish out your sanding with some 400 and then 600 grit sandpaper and then start buffing. These are the ones I use and they work perfect. This kit comes with a 1/4" mandrel but you'll need a 1/8" mandrel to fit a Dremel. (Otherwise you can use the 1/4" mandrel in an electric drill.)



http://www.eastwoodco.com/shopping/p...iProductID=944

As for the buffing stage, once you've sanded to 600 grit you should start off with a spiral sewn cotton wheel and some black emery compound on either a bench grinder or some type of high speed rotary tool. You can get spiral sewn buffing wheels and compounds at just about any hardware store. They look like this:



The compounds you want to use are black emery and white rouge. Start off with black compound on one of the wheels pictured above to cut the sanding scratches down and smooth out the surface. Once you've buffed out all the scratches and got a little bit of shine, then you finish up with white rouge on a loose cotton wheel to bring out the bling. Loose cotton wheels look like this:



All of the wheels and buffing compounds can be purchased from Eastwood as well. This art takes alot of practice so don't get frustrated if you can't get the finish perfect the first time around. Make sure you're thorough in sanding with each grit because whatever you don't sand out from the previous grit will show up in the final finish. Good luck.

 

Wow, much more detailed answer than I was expecting, thanks a lot!