I'm stalled mid way through my h/c project as I'm waiting for parts to arrive, so I decided to take on polising some parts just to keep myself busy. I figured I do the alternator, intake manifold, water pump and MAF. But how on earth to you get down into the little curves and angles and everything. My dremel won't fit, and I can't even seem to get it with sandpaper (60 grit) Is there any trick or special tool I should be using?

 

"Aluminum Polishing - The clear coating used on bare aluminum parts like engine side covers and fork sliders yellows and peels. At some point it becomes better to polish the aluminum rather than put up with the unsightly, cracked, yellowed coating.

I take it off by using steel wool and polishing compound. Use 000 steel wool and lots of Simoniz Chrome Cleaner, which is available at auto supply stores. This stuff has an abrasive in it, so it does cut fairly quickly. By glopping the compound either on the wool or the part, and then rubbing with a circular motion, the coating, corrosion and dirt can be cut using moderate elbow grease. It takes a little time to get into tight corners. After a consistent finish is achieved with the steel wool, I then go back with more compound and a soft, damp cloth and repeat the process. The steel wool gives the aluminum a matte finish and the final buff with a cloth brings out a little shine. This process doesn’t give a high shine, but produces a finish similar to the factory. As a final step, use a high quality auto wax. The polish protects the bare aluminum from quickly corroding. For a high polish, I use a cotton buffing wheel on a power tool, but that’s another discussion!

If the aluminum is badly corroded, start by using a wet/dry 400 or 600 grit sandpaper and generous amounts of water. The sandpaper (3M Brand) can be purchased at the local hardware store. Depending upon the depth of the pitting, it may take quite a bit of sanding before the surface is smooth and pit free. Don't skip work at this step as it will only lead to disappointment at the finishing step. When the surface is smooth, go to the steel wool as described above. Good luck! Randy Steinmeyer"

quoted from http://www.yamaha650society.com/alum_polish.htm (have to highlight to read for some reason)

 

You can grind off the casting marks and such with smooth dremel rolls, for the very tight spots you could try using something like , cone (pointy) sanding rolls