A collectors' guide to looking after your coins
Whether you’re new to collecting coins or have been an avid collector for years, looking after your precious coin collection is arguably one of the most important aspects of numismatics. The years of hard work, passion and dedication that you’ve put in can be easily undone without the proper care and attention to your collection. So whether you’re new to collecting coins, or simply looking for some simple ideas, here are a few tips on how to look after your coins.
Unless its absolutely necessary its always best to avoid direct contact with your coins. Even if your hands are clean there can be tiny traces of oil, grit or dirt that can damage and harm your coins.
Where possible always leave your coins in their holders or capsules, but if you have to remove them, always hold the coins by the edges. There is never a good excuse to touch the face of a coin with your hands as the oils from your fingers can damage the metals.
If you’re right handed, use your right hand to pick up the coin to reduce the risk of dropping them. For extra security you can always hold your left hand underneath the right, just on the off chance you do make a mistake and the coin slips from your fingers.
When the greatest risk to damaging your collection comes from dropping them onto sharp, dirty and hard surfaces, you can provide some extra security by using a soft surface when examining your coins. A felt-lined case or even a cloth will provide some additional protection if you accidently drop your coins. If using a cloth, make sure it’s thick enough to absorb any impact from an unwanted slip. Also check the cloth to ensure there are no traces from unwanted washing liquid present as the chemicals can harm the metals.
Hand sanitizers are a great option for cleaning your hands prior to handling. The alcohol in the solution helps to remove excess oils from your fingers that can have a corrosive effect on the metals.
Some experienced collectors used gloves when handling their uncirculated or proof coins. The gloves should be thin enough to provide dexterity to your fingers, and soft enough to avoid any abrasions. Clean, thin cotton gloves are a good option.
Coin tongs are often used for handling coins to avoid the numerous skin based oils and acids that can be easily transferred to a coins surface.
Many people use them during the cleaning process (see below before you decide to clean any coins) where coins are dipped into cleaning solutions and solvents. If you are using a cleaning solvent ensure that you’re not going to cause any irreparable damage to your coins.
If you’re unsure it’s always best to find a local coin dealer and ask for advice.
If possible it’s always advisable to avoid cleaning your coins.
When metal is exposed to air it is quite natural for them to oxidize and tone, cleaning your coins will remove this tone and strip them of their mint luster. Cleaning will also subject the coin to abrasive actions that even if performed gently can show up under microscopic examination.
Scratched or damaged coins will result in a reduction of value, and overtly clean coins can even deter collectors from being interested in your prized collection. Collectors want coins that look natural and often won’t be interested in adding clean coins to their collection.
If you really want to clean them and you’re limited by budget, then use a plastic container (to avoid scratching), distilled water and a very small amount of washing liquid. Rub the coins gently and softly between your fingers and then rinse in a fresh batch of distilled water. When clean leave them on a soft surface to air dry.
Gold is a relatively soft metal and it’s actually quite easy to leave scratch marks on them from overly aggressive cleaning.
Using metal polishes that you may have around the house is definitely not advised. You can use a small amount of washing liquid and gently boil them in distilled water to remove any dirt. Never dry them with a cloth and again, leave to dry naturally.
If you have a soft brush you can gently apply this to the surface, but be mindful of any dirt or grit that could cause a scratch.
Although gold doesn’t rust, the steel boxes in which they’re sometimes stored can. If the coins come into contact with this rust they can become stained. Most of these stains can be easily removed with a number of relatively weak acids (lemon juice, vinegar).
Soaking your gold coins in these solutions will gently remove these stains. The duration will depend on each individual coin but be sure to regularly change the solution. This method can leave them slightly sticky, but rinsing well with distilled water should resolve this.
Fingerprints and even Sellotape (some people use this to keep their coins in place during postage etc.) can leave a residue or unwanted stains on your coins. Acetone should remove the vast majority of stains, but ensure that you work in a well-ventilated room as the fumes are toxic and a little overpowering.
If you have some low quality silver coins that won’t be harmed in value by cleaning, then using a silver coin cleaning fluid will be a good option. However, silver acquires a certain tone with age and a tarnished coin can actually enhance its desirability.
In some instances this tone will take on an “oily” effect, producing hues of blue, green, indigo and violet. Do not clean any silver coins with this type of appearance as they’ll lose their appeal, allure and value.
If your silver coins have a fair amount of dirt remaining on the surface, a mixture of distilled water and citric acid (lemon juice) at a ratio of 4 parts water to 1 part citric acid, will help remove the dirt. Soak anywhere from a few hours to a few days depending on each individual coin.
Never use on silver coins like antoniniani as it will remove a layer of silver from the coin.
Bronze coins are easier to ruin that gold or silver and frequently look an unpleasant brassy colour after they’ve been cleaned. However if you have ancient copper of bronze coins and you’d like to remove some dirt from the surface or lettering, then simply using water and a little detergent is a good place to start. You can gently apply a brass bristle brush until the design has been liberated from the dirt.
Be careful once the initial layer of grime has been removed as you don’t want to remove any of the patina of the coin. If you see areas that have become shiny, immediately stop. You can always come back to cleaning once you’ve had time to re-assess what’s required.
Removing unwanted minerals
Another method that is becoming increasingly popular is a mixture of sodium hydroxide (NaOH), also referred to as lye. It’s been proved to work especially well with non precious metals badly encrusted with minerals. It can be purchased from a number of hardware stores but take care and read the instructions carefully. The mixture can heat up on its own when mixed with water and can give off poisonous fumes.
Some bronze coins can take on a blue or greenish color if they’ve been stored in wet or damp conditions. This disease can release tiny amounts of hydrochloric acid that can attack the coin and destroy it over time. Without adequate treatment it can get worse or re-appear even after cleaning.
Manually remove as much of the rot as possible and then soak the coin in distilled water for 30 days.
Be mindful to change the water daily if possible. Once complete and dry you can then use a microcrystalline wax polish to protect the coin from the disease re-appearing..
If using any solvent or solution to clean your coins, it’s always recommended to remove any traces of these substances once you’ve finished the process. One of the best methods is to simply use distilled water.
Soak your coins for 2 weeks changing the distilled water every day. This should remove any traces of chemicals and solvents .
At the higher end of the market are digital ultrasonic cleaners that use ultra-sonic waves to dissolve dirt particles.
These are pretty good for coins dug out of the ground, covered with dirt, mud and grit, but for your precious coins, as always its recommended not to clean them. Some ultrasonic cleaners also need a detergent to work effectively; it’s recommended you check that the solution you use is ok for the individual metal of your coins.
Coin show etiquette
When coin dealers attend shows they often bring the very best of their collections to show and sell. It’s therefore important to show the proper respect to other peoples collections and handle them just as carefully, if not more so, than your own collection.
If a dealer allows you to pick up a coin to examine at a show, please pay attention to any soft surfaces they may provide. Ensure that when examining a coin, hold it over these surfaces to minimize the risk of any damage. Again, never touch the face of someone else’s coins; even if it looks a tad on the rustic side.
If the coins are housed in holder, then ask the dealer to remove it for you as they may prefer the coin to maintain in its casing. Common courtesy and consideration should always be at the forefront of your mind when viewing or handling someone else’s collection.
It may sound strange but it would also be advisable to breath through your nose when examining a coin up close. The breath from your mouth contains moisture that if transferred to a coin, can cause damage later on.
Putting the dealers mind at ease
The unfortunate reality is that some coins do get stolen during shows.
They can be dropped into bags or hidden between the pages of a checklist when the dealer’s back is turned. It’s therefore important to put the dealers mind at ease when at their table. Never put bags on your lap when sitting down as this could be seen as a potential threat. If possible keep any bags away from the table or hang them on the backs of the chairs to show that you’re not about the take off with some of their prized collection.
If you have a checklist try to keep the papers away from the coin collection. Again, slipping coins into a notepad is one way coins can be liberated from their owners. Always put any paper on the table but away from the coins.
Being clear about what’s in your hand will also help put the dealers mind at rest. Showing your hands palm up before getting something from your bag (like a magnifying glass) helps show that you have nothing to hide and don’t harbor any ulterior motives.
One of the most popular methods for storing coins. These 2”x4” cardboard holders are lined with plastic and when closed are typically stapled shut to protect the coin. The coin will be visible through the plastic lining but only on one side. An affordable and popular option for storing coins.
These are small plastic pockets used to hold one coin. They often have two sections, one for the coin and one for a cardboard description. Many dealers often use these, as they can be stored sequentially in long boxes for easy categorization. Similar in principal to the coin holders above but the plastic covering on both sides protects the coins from the elements and scratching. Slightly more expensive than the cardboard option.
Hard Plastic Coin Holders
These offer some of the best protection and are made from inert plastics that don’t secret harmful PVC materials onto the coin. They can also be custom made to house and display entire collections. The main disadvantages are the cost and they’re not always easy to store due to their bulk and size. These are ideal for the more rare or expensive parts of your collection.
One of the cheapest methods for storing a wider selection of your collection. These are typically cardboard folders that allow you to store a large number of coins in a convenient and organized way. Circular holes are cut into the folders allowing you to view and display your collection. Each hole may have a date and description providing an insight into each coin. The main drawback of this method is you only have one side of the coin on show at any one time, and often they’re not covered leaving the coin exposed to the environment.
Coin albums allow you to view both sides of the coin at the same time. Plastic inserts also can be applied as and when your collection grows, protecting your expanding collection from fingerprints and the elements. A cardboard slipcase can also be applied to the entire folder, adding an additional layer of protection.
Stackable Coin Drawers
One of the best way to safely store, organize and display your coin collection. Its stackable design and size mean it is easy to store on shelves or in cabinets, and is easy to move around when transporting coins to shows or dealers.
Hopefully you found some of these simple tips helpful and if you follow the guidelines your coin collection should be well protected and secure in the months and years to come. Happy collecting.
About the author: This post was written by Arrowfile. A collectable coin storage specialist.