I have a collection of about 70 coins, a mixture of circulated and uncirculated. Several years ago I bought binder pages specifically intended for storing coins, in the expectation that they would provide good archival protection for the coins. The pages I have are shown here: http://www.safealbums.co.uk/Zen/index.php?main_page=product_info&products_id=2261 I noticed recently however that some coins show mild toning (I think that's the right term), so I'd like to take action now so that this toning doesn't get any worse. I don't know exactly what has caused the toning. The pages and the binder themselves should be "archival-safe", and the binder is kept in a bedroom at normal household temperatures. But maybe this process is unavoidable since the coins are not in airtight storage? I also live in an area of year-round high humidity. I have a cheap indoor thermometer/hygrometer, which is currently reading 19°C (66°F) and 61% humidity. I'd appreciate suggestions for better archival storage options. Ideally I'd like to be able to view both sides of my coins, and I'd prefer the storage solution to be reasonably compact and not bulky. Are 2"x2" cardboard holders (stored in binder pages intended to hold 20 such holders) a good option? (I saw these listed on hartberger.com.) Would I be better off seeking out hard plastic holders? Individual coin capsules are another option, but they don't seem a very convenient storage option to me. Thanks for your input. Edit: These stacking trays are another option that I thought looked efficient, but, since they also don't appear to be airtight, maybe they'd be no better than what I have already? http://www.safealbums.co.uk/Zen/index.php?main_page=product_info&products_id=5833
There are no coin holders I know of that you can buy that are air tight. The best you can do is Intercept Shield products. These are also not air tight, but they have a chemical in them that grabs sulfides out of the air so less of them can get to your coins.
If I were you I would looks for airtites and their accompanying albums. You first put the coin in a capsule which helps stop air flow and then that capsule goes into an album with pages which will again reduce any more air flow (You will always have some). Other than that, Tupperware containers are best and desiccant packets inside of that should suck up any additional moisture.
It's the atmospheric sulphur that's the culprit if the storage media is inert. Short of a vacuum chamber, we're talking different degrees of minimizing, as opposed to eradicating, the exposure. Once it gets on, takes, i.e., is environmentally damaged, as such, a dip is the only thing I know of that has any chance of bringing it back.
For protection of large albums, boxes, sacks of coins: Use 2 of these bags. http://www.amazon.com/Ziploc-Double-Zipper-X-Large-4-Count/dp/B003U6A3EY Put your coins/ album inside the first giant one, Take a regular ziplock quart bag, use a paper punch and put some holes in the quart bag. get some new copper cents, scratch the outside copper coat with an abrasive surface and put them into the quart zipper bag and seal it, put the quart bag in the large bag and seal it. The abraded 100% copper on the new cents will collect any sulfur or reactive chemicals in the air better than the other coins. When a copper cent in the holed quart bag even turns slightly RB, replace all of them and your protection begins again. If you are really paranoid, put a similar punctured abraded cent filled bag in the second giant bag and insert the first giant ziplock into the second giant bag and zip, and dare any corrosion to occur. It is ugly, but protective. Use as many repetitions you wish. Only need a few new cents per bag, but check to see if any turn RB more often at first or if opened often. Intercept shield works the same, except they use to be (1) non replaceable shields, and (2) no way for the owner to know when they were not working other than the coins they were protecting would start to show damage. Total cost is low.
