How Do I Keep My Red Pennies From Turning Brown.

The longer they are exposed to the general atmosphere the more likely they are to gradually evolve toward brown shades. Best way is to enclose them in the best air-tight holder you can afford given the value of the coin - there are many inexpensive alternatives.

I have a system that was discussed here, it seems to work well.

http://goccf.com/t/245156

Cheers, Bill

I have tried this ONCE only, many years ago.
Wash in acetone, let dry, then spray with clear coat acrylic lacquer.
This lacquer is easily chipped, and differential toning can result in disaster. To avoid this. put the coin in an appropriate sized screw sealed acrylic capsule.
The coin can later be removed, and the clear lacquer removed with acetone.

Should retain rainbow coloring forever.

Experiment with a cheaper coin first.


The Royal Australian Mint uses weld sealed acrylic capsules for their high value proof coins. The coin will remain imprisoned forever in freshly minted state, until the capsule is destroyed, but you risk damaging the coin in the process.

Not touching the coin is the first step to protecting it, because toning can happen when the coin comes into contact with acids and bacteria on a person's fingers. Sometimes this even leaves fingerprints that are the worst form of toning. Next, you need to protect the coin the best you can from contact from dropping it and from the environment (moisture in the air). Mylar does a great job of protecting, but these days we also have access to coin capsules and "do it yourself" coin slabs. However, if it is a high valued prize penny, then you probably would be better off sending it in for grading and having it professionally slabbed. But, do not think because it is slabbed you can toss it in a wet moist environment, and it will not tone within the air tight slab. You need to keep your coins in a dry environment away from moisture. Silicone packs placed near your coins is a cheap way to help protect them. Some people use mini dehumidifiers or place their coins in a room with a dehumidifier running all the time. Vacuum sealing your slab can add extra protection, but be sure the plastic bag is safe for the coin. Keep your coins away from iron because when it oxidizes (rust), it releases gases that will penetrate even slab holders and cause coins to corrode. I used to keep all my Commemorative coins in their original government boxes until I discovered the boxes were made out of cheap steel that rusted and cause the coins to tone and develop spots. The big enemy is moisture and other metals that are oxidizing. Gem BU Red pennies are all lightly oxidized the moment they leave the Mint. This process actually helps prevent further toning, but what happens is that most dealers and collectors keep their coins in a high moisture environment without even knowin git. A damp cold closet, iron safe, or attic is not the place to store coins.

I cannot say if lacquer works or not, but I would warn you against doing it. Every coin that shows up on ebay that has been lacquered ends up losing value. People want Gem BU Red with original Mint Luster, not something that was cleaned with nail polish remover and covered in a coating of lacquer. You want to protect the original Mint Luster as much as possible, and I do not believe putting lacquer on a Gem Red copper coin is a good idea. Maybe it would be okay for a circulated Large Cent, but not on a mint condition coin of any metal content.