A Little Help From My Friends .

I read somewhere here on the forums that putting a bit of scotch tape over the open sides of a 2x2 can help cut down airflow and help prevent changes in toning.

I mentioned glue from the self adhesive 2x2s as a concern before and someone brought up what about the glue that attaches the Mylar to the cardboard? I don't consider 2x2s for long term storage of high grade coins, preferring air-tites and Saflips, but your result is surprising and very concerning.

ok, you guys have me thinking.
I have built a metal barn , made it into my house.
built a 4x11 closet that have chip type shelves.
the store next to me gave me 88 , 2'x4' foot shelve boards . I have built shelving out of them.
my coins are in slabs , 2x2 card board holders , zip lock bags and bank type rolls (open end).
proof sets , mint sets and silver eagle boxes , all from the mint.

what should I do ?
sorry to bust in this post, but it might help another.

And put silica gel inside the bags as well! Copper is very reactive and moisture is a major source of toning. The toning reaction is usually an oxidation reduction reaction that REQUIRES moisture to proceed. If you don't want the gel in the bag with the coins double bags them and put the gel in between the bags.

T-bob: my numistmatic heart goes out to you. That's a similar tragedy to stamp collectors who find out that their saving procedures resulted in panes of stamps stuck together like plywood.

I use silica gel pacs also-any clue on the shelf life of these? Ive heard conflicting answers in the past from people

I would think that would be one reason as to why they toned. You don't know how they where handled prior to you getting them. Using acetone will remove the oils left behind from someone touching them (not patina or toning).

Unless you have a temperature controlled room you should definitely keep coins stored in a way to protect from humidity. The zip-lock bags with silica is the way to go in my opinion. I only use the silica with the indicator on it so I know when it is time to recharge them. Storing the coins in anything wood without this layer of protection is a big no no to me. Wood absorbs moisture and releases it unless it is sealed, but then you would have to consider the type of sealant used. Keeping coins in 2x2's only protects them from getting minor scratches and being physically handled.

You not only have to protect your coins from the elements but also from what you use to protect your coins. It's a vicious cycle.

Thanks for the warning - I'll check and make sure this doesn't affect my collection.