Polishing a Micro Seiki RT 3000G Gunmetal platter

Guys, I think what @horsestuff has in mind is removing the tarnish from the metal, like polishing silver.

There are hundreds of metal polishes out there. I personally like Menzerna Polishing Cream. It is a rub on, wipe off product, a cotton or microfiber cloth will do. You could use a random orbital polisher, but on something as small as a platter elbow grease will do fine.

@horsestuff  

The orbital polisher will fling polish all over the place unless you are very experienced with it. The Menzerna Polishing Cream works on all metals and you will need very little elbow grease with it. The tarnish will rub right off. I tried it on gunmetal parts of a hand plane. Worked great. 

@pindac 

All true, except clear metal lacquer is really toxic and difficult to apply. The stuff you get at Home Depot will leave a bad finish with pits and runs. It is much easier for the OP to polish the platter once in a while.