PVC in its pure form is a hard material, needing special chemicals added to make it soft and bendy — required for making soft album sheets, envelopes, or the soft vinyl flips often used for coins.
Admittedly, it can be frustrating for a long time to incorrectly store a coin that originally cost several thousand dollars. Therefore, in any case, before changing the storage method, it is better to determine the grade token through a coin checker in order to understand what you are working with.
The Cause of Damage: The softeners slowly start leaving the soft PVC material over time, happening faster when the place where coins are kept is very warm or the air is very wet, causing a bad chemical reaction when they touch the coin’s metal.
Speeding up the Process: High temperature and high water in the air speed up the process of these softeners leaving the plastic, making them start eating away at the coin’s surface much quicker.
Clear Signs of PVC Damage
PVC damage always looks like a sticky, oily, or gel-like layer sitting on the coin’s surface, having different colors depending on what metal the coin is made of.
- On Copper Coins: The sticky layer often appears green or blue on copper and bronze coins, looking like a wet or waxy substance that is hard to touch.
- On Silver Coins: The sticky layer might look clear or yellowish on silver and gold coins, always feeling sticky when you touch it, meaning you must clean it right away to save the coin.
- The Bad Outcome: If you don;t quickly clean the sticky layer, it causes the metal to start rusting and breaking down, leaving small holes and dark spots on the coin’s surface, being a permanent defect.
The Damage Cannot Be Fixed: The holes and spots caused by PVC damage cannot be fixed, greatly lowering the coin’s value, making the coin not suitable for serious collecting anymore.
Strict Rules for Stopping PVC Damage
The only sure way of stopping PVC damage is never storing your coins in any material that contains these softeners.
Using Safe, Good Materials: You must only use plastic materials that are known to be chemically safe and not reacting with the metal, being good for long-time storage.
- Polypropylene is a hard, safe plastic, being used for making modern album sheets, folders, and coin boxes.
- Polyethylene is also known as a safe plastic material for keeping coins.
- Mylar is very stable, being often used for making coin envelopes and hard holders.
How to Know the Bad Material: You must treat any soft, bendy plastic envelope or album sheet that doesn’t say what it is made of as possibly dangerous, meaning you must not use it for your important coins, which you previously checked with the coin values app.
If the plastic is easy to bend and stays soft, it probably has softeners inside.
Best Storage Method: Storing your coins in hard plastic boxes, often made of acrylic or polycarbonate, is the safest method, these hard materials not needing softeners inside them.
How to Clean Away PVC Damage
If you find that a coin already has PVC damage, you must quickly start the process of taking the bad material away from the surface.
- The one method that is safe and suggested, not hurting the coin’s metal, is putting the coin in a bath of very clean acetone, which melts the softeners.
- The coin is completely coated with acetone for a while, which is necessary for the acetone to dissolve all the sticky material.
- Never rub or wipe the coin when removing the sticky layer, as the softeners can harden and cause scratches on the surface of the coin.
- After you remove the acetone coin, you should rinse it in clean distilled water, not tap water, and then let it dry on its own on a clean, soft cloth without wiping it.
Protecting Coins from Air and Conditions
Damage from the surrounding air and conditions means any bad change in the coin’s looks, caused by the coin mixing with oxygen, water in the air (humidity), heat, and dirt.
Controlling Heat and Wet Air
Both heat and wet air are key things, making all bad chemical reactions happen much faster, causing the coin to spoil.
You should store your collection in a place with a constant room temperature, avoiding high temperatures that accelerate the release of emollients and rusting of metal. Don’t store coins near heaters, on sunny window sills or attics.
A lot of water in the air is the main reason for rust and bad spots on coins, making the water sit on the coin’s surface, starting a bad reaction with the metal.
- The best level of water in the air for keeping coins safe is between 40% and 55%
- In places that are often wet, it is a good idea to use machines that dry the air or put small packets of drying material inside the storage boxes
Stopping Rust and Color Changes
Color change, or toning, happens when the coin mixes with oxygen, sulfur, and other gases in the air, creating color on the surface.
On old silver coins, toning that is even and looks good is often seen as a good thing, showing the coin has been kept safe for a long time, often making the coin worth more money.
Uneven, dark, or rainbow-colored spots, and also cloudy white “milk spots”, found on modern silver coins, being caused by chemicals left from the making process, are seen as bad defects.
- Sulfur is the main thing that makes silver and copper turn dark, meaning you must keep your coins away from things that have sulfur
- Don’t store coins close to things that have sulfur, like rubber bands, certain kinds of wood, old glues, or low-quality paper envelopes
Sealed Protection: Storing coins in hard plastic sealed slabs is the best way to protect them, sealing the coin away from the air and gases.
Simple Rules for Touching Coins
Touching the coin in the wrong way is a direct cause of physical damage and chemical damage.
Human skin always has oils, fat, and sweat, leaving fingerprints that are easy to see and chemically active, slowly moving into the metal, making permanent damage that cannot be cleaned away.
You can see the difference in price for the touched and untouched tokens of each series using the coin value checker app.
- You must always use clean cotton or nitrile gloves when touching your coins, especially the ones that are very nice and new.
- You must only hold the coin by its small edge, never touching the main flat surfaces of the coin.
- Always work with coins over a clean and soft surface, like a soft cloth, stopping the coin from getting scratches if it falls.
Checking Your Coins Often
You should check all the coins in your collection at least once every year.
- Look for early signs of problems: the coin feeling sticky, new dark spots, or color changes that look bad or uneven.
If you find any problem, the coin must be taken out immediately from the bad material and put into a new, safe plastic holder or capsule right away.
