Copper Storage?

[Bennett]

I seem to recall reading that copper coin collectors don't like to keep their valuable coins in TPG slabs. Something about them changing color more easily in slabs. Is this true, and if so what's the preferred method of storing copper coins? 2x2s? Thanks for any information.

[physics-fan3.14]

The easiest way for me to store copper is to sell it to someone else. Copper makes me nervous. (But, someone who does collect copper will come on here soon and tell you everything you need to know.)

[numismatica]

 

Buddypal,

 

The answer to your question is two-fold. The holder is important, but so is the actual environment. If you live in a hot and humid area (i.e. Florida), then you will want to take extra steps to protect your copper.

 

The holder of preference by EAC guys is a cotton pouch that fits into a 2X2 paper envelope. There are other options as well, but avoid PVC flips at all cost. The damage to copper begins immediately if you use such a holder.

 

If you live in an area with humidity issues, then you will want to keep your coins in your bank's climate controlled safety deposit box, or in a climate adjusted area in your home with silica gel to help absorb moisture. It is not as bad as I make it sound, but better to be safe than sorry.

 

Regarding the slab question, it is too early to say what the long term effects are, but I have seen plenty of early copper that has turned in holders. It may not be the holder's fault, as the coin could have had chemicals on the surface before being encapsulated. My gut reaction has always been that it doesn't make sense to shroud a coin in material that is made from oil (plastics are petroleum-based). Ever crack one of the small ANACS slabs? The chemical stench will literally knock you back a few feet.

 

 

[BillJones]

I've never a copper coin that had its natural shell of protection turn bad on me. Coins that have been fooled with are quite often a problem. Numismatica had it right when it comes to storage. Keep the coins stored at a steady temperature in a climate controlled environment, and should be OK.

 

I avoid red copper because it is too fragile. But even with that I've had decent luck with slabbed pieces. I've never had problems with brown or red-brown copper. And for the copper coins I really like, that is only color the makes sense. So-called old red copper coins (1850s and earlier) are often dull and lifeless. They are now worth the price IMO. I've had brown pieces with full cartwheel luster, and those coins are the best. (thumbs u They are very stable. and fun to own.

[James_OldeTowne]

If a coin is naturally patinated by exposure to a natural environment, then that yields it protection against further degradation. However, introduce that "natural" coin to an unnatural environment - such as a completely unventilated plastic-saturated environment - and what happens?

 

Only time will tell, but for me personally, I have my copper carefully tucked away in mylar.

[Oldtrader3]

Like Bill said, the cupric oxide coating on RB or BN copper coins greatly protect the surface from corrosion. I would not assume that the local bank has climate control on weekends. I live in soggy western Washington and have had even RB coins turn in my safety deposit box. The local small town bank turns off the heat or air conditioning on Friday night and turns it back on on Monday morning. I would not store any more copper or bronze coins in a safety deposit box without a desiccant container in with the coins, even in Mylar or slabs.

 

I believe that most slabs are probably molded from PET (Polyethylene Terpthalate) or PETG ( with Glycol) or some other similar food grade, crystalline plastic. However these do release plasticizers (maybe magnesium or zinc Stearate) in small amounts with higher temperatures, as in an non air-conditioned bank on a summer weekend. These Stearates would also probably be reactive with non oxide coated copper.