What are the tricks?

Thanks,
Frazer

If the alluminum is already smooth and just tarnished use a little mothers mag and alluminum polish on a clean towell (warning you will just about destroy the towell it's going to turn black) buff the alluminum and then get another clean towell (I prefer cloth diaper type) and finish polishing with it.
If the piece isn't smooth ir has some kind of finish on it that is all together a different process.....

Mother's brand mag wheel polish. Its safe for all metals. Also, plenty of white cotton rags. Possibly a small orbital buffer. Ask Raybeard about polishing. I have seen a glimpse of his polishing results through email pictures, and I was truly amazed. Aluminum hubs appeared to be chrome plated. No joke.

Hi Frazer, the best stuff to polish aluminum with is Blue Magic. It comes in a liquid or paste and is available at an automotive supply store. The liquid form works the best and will give it a chrome mirror finish. This is the best stuff "HANDS DOWN" guaranteed. I've tried everything under the sun and when I discovered the "Blue Magic" my quest was over.

Mothers is good if you only want a simple cleaning and a not so good polish,
I prefer the Dremel Polishing kit i picked one up at Wal-mart it cost about 12 bucks.

What i do is install the polishng wheel onto the dremel turn it on dip the tip into the polishing container (The Red Compound that's hard it softens up when the wheel hits it) apply it to what you want to polish it turns black but don't worry keep moving in other directions don't just keep it in one place. By moving it around you don't over heat the metal to much keep moving over and over the surface and after a little work the black polish comes off and it has a much more shiney finish (Like Chrome) than just rubbing by hand with Mothers mag wheel polish ever can.....

Or you could take it to a place to have it "ball burnished", this will put a nice shine on the frame or the part (not mirror though) and you'll never have to polish it again because for some reason, after this process is done the part will not tarnish.

Guys,

Great ideas, all of them! I will start the experiments. Thanks for the time and insights.

Frazer

Materials needed:
Sand paper 80-600 grits (depending on the condition of the metal)
Terry Cloth towels (the softer... the better)
Safety Glasses
Your favorite BBQ apron
Dust mask (unless you like aluminum dust)
A reputable aluminum polish (I use Eagle One, http://www.eagleone.com/_products/index_whe.asp)
Dremal Tool or pneumatic hand drill (high rpm) with hard cotton polishing wheels
Palm or Mini-Finishing Sheet sander pneumatic or electric (This is a must)
Time and Patients (As well a must, a must have to get good to excellent results)

Cleaning up the metal, if you are dealing with rough or raw aluminum you will want to follow these sanding steps (I use all of these steps when restoring OSBMX Aluminum, note: not all OSBMX manufacturers products were polished to “high luster” or show standards... Phil Wood Spiders for example were not OEM high luster):

Warning: Do not over sand... aluminum is soft and when using pneumatic or electric sanders, you can thin out tubing etc reducing the structural integrity of the component or possibly “sand through” the tubing /component. Do not sand out factory welds or factory markings, this reduces the historical value of your component.

Sanding Steps:
Using pneumatic or electric sanders can greatly reduce your man hours...

80-120, grit Medium Smoothing of the surface, removing deep imperfections and marks.
150-180 grit, Fine, removing smaller imperfections and marks and leveling out dips in the aluminum.
220-240 grit, Very Fine Sanding
280-320 grit, Extra Fine
360-600 grit, Super Fine Fine sanding of the finish to remove some luster or surface blemishes and scratches.

Once you have put more aluminum shavings up your nose than the guy in “Blow” snorted illegal drugs, follow these procedures:

Take your terry cloth towel collection, cut the towel to fit your Palm or Mini-Finishing Sheet sander like you would a sheet of sandpaper, slather on the Mag & Aluminum Polish and polish away... you might need to do this several times to get a scratch free mirror shine. Use your hand Held Dremal Tool or pneumatic hand drill (high rpm) with the polishing wheel attachment to polish welds and those hard to get to spots (use plenty of polish).

After you have made a huge black mess of everything on you work bench, and you are 110% satisfied with the look of your hard work an time (in other words you could use it to shave with instead of a mirror in the mornings), use a common Silicone Glaze car wax to seal and protect the aluminum, this reduces natural tarnishing. The car wax will work, but I found another product that I have been happy with, Eagle One Billet Aluminum Polish Cleans, polishes and waxes to a mirror-like shine. The choice is yours, they both work great.

Titian’s disclaimer: I have polished allot of aluminum... this is the best way I have found to do it. I am by no means an expert. Do this at your own risk. Like mentioned above, this takes allot of time and patients... these two factors will be crucial in the outcome of your project. Prepare to get dirty! Good Luck!

*bump*

ive yet to restore any billet or regular aluminum parts in bmx yet,but bein that ive been in the custom car/truck scene awhiles,i found nothing works better for polishing than WENOL.it comes in a toothpaste style tube and works amazing with only a small amouth of polish on your cloth/rag.i have a set of polished aluminum rims on my truck,well,i went at them with a drill and a 4.5in polishing wheel and well,they look insane!!