Copper coin preservation

[Gabe]

What are the best ways to keep copper coins from tonning, spotting and from other problems that plagues copper?

I have heard to mineral oil for preservation. I have heard of a way to remove carbon spots and to 'detone' a toned copper coin. Are these claims true? What do you use?

[Bob P]

Hi Gabe....
I have heard of some of those claims about removing carbon spots and 'detoning', but I am uncertain about any of them. All I know is that cleaning is a no-no. But...saying that, I have also heard that in some cases, it might actually be better! A simple answer is I just won't trust anything until I could try it on an inexpensive coin, and then wait a while to see what happens.
I have managed to keep copper coins looking great, as long as they are in non-PVC flips, and stored away somewhere dry,and preferably dark. Light, heat and fingerprints are the main culptits on any coins, but are especially noticeable on coppers. I would recommend either the flips, or airtight containers.

[rollmeupabe]

Bob, when you use the term "flips" are you including the cardboard coin holders or just the vinyl style holders. I started storing my varieties in the cardboard style holders a few years ago and don't know if that is a good choice for long term storage.

[Bob P]

I was referring to the non pvc generic archival double pocket vinyl flips. These contain no oils or softeners either. I call the cardboard ones 2 X 2s. I still have many that are in the 2 X 2s with no apparent damage done to the coins, but they do tend to yellow, and break down over time. I do not know what the long term damage would be (if any) to coins stored that way.