When I first got my motorcycle the fins on the bike were oxidized, and the paint was all chipped up. I scraped the old paint, sanded it down then painted them with VHT Header Paint and left it. This weekend I went through the process of sanding the flat portion of the fins and polished them to a mirror. The Honda Shadow ACE has removable fins on it so if your bike doesn't have the removable fins, then just follow the instructions just know it will be a bit more difficult.

Step 1: Sanding

First you will need to sand down the fins flat with course grit then progressively move towards a finer grit sandpaper.

I started by using 120 grit to take off the black paint, however I quickly moved on to 180 grit in order to avoid deep scratches in the aluminum.

As you move towards a finer grit you can then wet-sand the fins to avoid scratches. Any scratches in the fins will have to be sanded smooth. Keep your sanding motions going lengthwise of the fins.

100 grit
180 grit
320 grit
800 grit
800(wetsand)
Buffing wheel

Step 2: Polishing!!

Polishing is the most enjoyable step as you really start to see the mirror image take shape. Make sure you are using some sort of buffing compound or polish, preferably one that will leave a wax to maintain the shine. I used a 6 inch buffing wheel on my bench grinder. I polished my fins 4 times while reapplying polish in between polishes.

If your cooling fins are part of the motor, you might consider using a higher grit before polishing. The steps are the same however you will need a drill or dremel polishing wheel... Or lots of elbow grease.

***Use safety glasses if using a bench grinder***