Brass and oxidation

[Zoins]

I've noticed unsightly black carbon oxidation spots on many brass tokens. Is there any way to remove these?

 

Is brass the worst possible metal to use for a token/coin because of oxidation?

[nwcs]

Carbon spots are difficult to remove. Places like NCS have chemicals that can help but for the most part you can diminish their appearance but that's it (without hurting the coin).

[just carl]

Note that Brass and Bronze are composed of Copper and miscellaneous other substances and with Bronze there is sometimes even Silicon added. Brass is basically composed of Copper and Zinc in various different proportions. Both of these metals are subject to Oxidation. As the Copper part Oxidizes it may produce a greenish patina whereas the Zinc has a habit of turning a blackish tone. Both of these together will Oxidize in just normal air providing Oxygen is present. Regardless, the contamination you discribe is unfortunate and in many instances to late for recovery. That blackish material is a portion of the coin and removal will remove metal from the coin. If you've ever noticed brass used in stores, hotels, your house, etc. the brass must be cleaned continously to prevent what you have noticed on the coins.

I suggest you leave it alone but seal all such coins in a air tight plastic holder. Even a standard 2x2 properly sealed will do that.

[MikeKing]

you're right about brass always having to be cleaned. Many of the clocks I work with are in brass casings or have brass bezels, and sometimes the patination can be quite lovely, at other times, outright corrosion. In which case, I take out the dremel and grind it off, and then polish it with microcrystaline wax at high speed buffing. Something, unfortunately, I wouldn't reccommend for a brass coin. Ouch.