Polish Aluminum

[Frank]

What is the best way to polish aluminum castings?

[gamblingman]

If you are working from bare castings, it is very hard to do correctly in your garage or shop. Take them to a shop that specializes in plating and polishing. Those guys will put a mirror finish on them for you with a lot less effort that you are going to have.

If you are just buffing off the oxidation and tarnish, I just use a cloth wheel on a table grinder type of motor and use a very fine buffing/polishing compound. I often double up the cloth wheel so there are two of the same size side by side, which gives me more surface area to work with.

[MONTI]

If your taking a fairly decent looking original casting that is a little oxidized and don't want to make it look like it just came out of the factory you can also get some great results by using a product called Tarnite or Nevr-Dull found at your local hardware store.
Brings out a nice clean look but keeps a little of the original patina.

[oldslotman]

If you are working from bare castings, it is very hard to do correctly in your garage or shop. Take them to a shop that specializes in plating and polishing. Those guys will put a mirror finish on them for you with a lot less effort that you are going to have.

If you are just buffing off the oxidation and tarnish, I just use a cloth wheel on a table grinder type of motor and use a very fine buffing/polishing compound. I often double up the cloth wheel so there are two of the same size side by side, which gives me more surface area to work with.

I really don't think you would want a mirror finish on them because I don't believe they came from the factory that way. A mirror finish would involve removing some of the metal to get it perfectly smooth. JMHO

[mechanic]

Nevr-dull or Simi-chrome both are good and are available at hardware stores. . Best is still a polishing wheel and polishing compound. You can get small amounts of compound and buffing wheels at a wholesale jewelers supply if you have one.