When it comes to preserving the value and beauty of your coin collection, knowing how to handle and clean them properly is essential. Whilst it might be tempting to scrub away years of dirt and tarnish, improper cleaning can damage your coins irreversibly and make them lose their value. Coins, especially older or rare ones, can lose significant value if cleaned incorrectly and damaged in the process. Their natural wear, patina, and even slight imperfections add to their charm and historical authenticity.
The key to coin preservation is balancing the desire for aesthetics with the responsibility of safeguarding their integrity. A shiny coin may look appealing, but removing the natural tarnish or patina could strip away decades of history, and with it, much of the coin’s worth. In some cases, a well-preserved layer of grime is exactly what collectors are after.
Should You Clean Coins?
Before delving into how to clean your coins, there’s one question you need to ask yourself: should you clean coins at all?
For rare, antique, or collectible coins, the answer is usually no. Many coin enthusiasts and numismatists, or coin experts, value the natural wear and patina that develops over time. This aged appearance tells a story, one that is often more valuable than a spotless surface. In fact, harsh cleaning methods can remove essential details or scratch the surface, dramatically reducing the coin’s value.
It’s crucial to assess the condition and rarity of your coin before attempting any cleaning. If you’re unsure, it’s always best to consult with a professional numismatist who can guide you in preserving your coin’s value. Remember, once the damage is done, it can’t be undone! For most rare coins, a gentle rinse in distilled water is the furthest you should go, and even that should be approached with care.
How to Clean Coins: 3 Safe Methods
If you’re dealing with common coins that don’t hold significant collector value, there are a few gentle cleaning techniques that can help restore their shine without causing irreversible damage. The key is to use non-abrasive methods and avoid harsh chemicals that might strip away important details or finishes. Here’s how to clean your everyday coins safely:
Basic Cleaning Techniques
For most coins, the safest cleaning method involves rinsing them in distilled water. Tap water often contains minerals or chemicals like chlorine that can react with the metal, so distilled water is the gentler option. To clean:
- Hold the coin by its edges to avoid oils from your fingers transferring to the surface.
- Rinse the coin gently under a light stream of distilled water.
- Pat it dry with a soft, lint-free cloth or ideally allow it to air dry naturally. Avoid rubbing, as even soft cloths can scratch the surface.
What Household Items Can you Use for Cleaning Coins?
If water alone doesn’t do the trick, you can turn to some common household items for a bit more cleaning power:
- White Vinegar: Vinegar’s acidity can help dissolve grime. Simply soak the coin for a few minutes, then gently scrub with a soft-bristled toothbrush. Be sure to rinse with distilled water afterward.
- Baking Soda: Create a paste with baking soda and distilled water. Apply it to the coin and use a soft cloth or toothbrush to gently rub the surface. This is great for removing surface dirt but be cautious on delicate coins.
- Olive Oil: This is a very mild option. Soaking coins in olive oil for a few days can loosen dirt. After soaking, rinse and dry the coin.
Chemical Cleaning Risks
While these household methods work well for common coins, using strong acids like vinegar or ketchup on rare coins can cause more harm than good. The acids may strip away patina or damage delicate metals, reducing a coin’s historical and monetary value. For rare or valuable coins, always opt for professional advice before attempting any cleaning. Bronze coins are especially susceptible to this as acids will revert the patina that has been achieved over time.
Advanced Coin Cleaning Techniques
For those dealing with more stubborn, heavily tarnished coins—especially encrusted finds from metal detecting or old collections—more advanced techniques might be necessary. However, these methods come with a higher risk of damaging the coin if not done carefully so make sure to only use these methods if you absolutely need to clean a heavily tarnished coin.
1) Electrolysis Cleaning
One of the most effective ways to remove heavy tarnish or encrustation is electrolysis, a process that uses an electrical current to gently remove grime without the abrasiveness of scrubbing. Here’s how it works:
- Set Up: You’ll need a power source, two electrodes (one for positive, one for negative), and a container filled with a solution of water and baking soda.
- Process: The coin is placed in the solution, and a small electrical current is passed through it. This loosens dirt and corrosion. Electrolysis is highly effective but can strip the coin down to bare metal if not monitored closely, so it’s best for non-valuable coins or those with thick encrustation.
- Assess: Only use this technique for a short time and watch the process closely to avoid over-cleaning.
2) Ultrasonic Cleaners
Ultrasonic cleaners are commonly used for jewellery and metalware cleaning and can be used for coin cleaning as well. Ultrasonic cleaners use high-frequency sound waves to remove dirt from the surface. These are more common in professional cleaning setups and are especially useful for silver and copper coins.
They work by vibrating the water or cleaning solution around the coin, loosening grime without the need for harsh scrubbing. However, like electrolysis, this method should be used cautiously to avoid damaging the coin. Ultrasonic cleaners are commonly used for jewellery and metalware cleaning and can be used for coin cleaning as well.
What about Silver and Copper Coins?
Soft metals like silver and copper require extra care during cleaning. Silver, for instance, can be easily scratched or over-polished, while copper is prone to tarnish. When cleaning:
- Limit Exposure: If using electrolysis or ultrasonic cleaning, limit the time the coin is exposed to prevent stripping away important details.
- Check Frequently: Always stop and check the coin frequently during the cleaning process. It’s easy to overdo it with these methods, and once damage occurs, it’s irreversible.
For collectors and hobbyists, these advanced techniques can work wonders on heavily tarnished coins. However, as with all cleaning methods, the goal should be preservation, not perfection. Always err on the side of caution, and when in doubt, consult a professional.
How to Determine Coin Value Before Cleaning
Before you even think about cleaning a coin, it’s vital to first determine its value. Many collectors make the mistake of rushing to polish their coins, only to find out later that they’ve dramatically decreased their worth. But how do you determine a coin’s value before cleaning?
Collectors grade coins based on a combination of factors: rarity, age, condition, and historical significance. But here’s the catch—the “condition” doesn’t necessarily mean how clean or shiny the coin is. In fact, collectors prize natural wear, known as patina, and certain markings that show a coin’s journey through time. Cleaning can erase these valuable signs of age, reducing the coin’s desirability.
So, if you have any reservations about cleaning your coins, you should try these steps first:
- Consult a Coin Expert: A professional coin expert can evaluate your coin’s rarity and condition, providing an accurate value assessment. They’ll tell you whether it’s worth cleaning or if it’s best left untouched.
- Check Online: Websites like Numista or NGC Coin Price Guide allow you to compare your coin to similar pieces, giving you an idea of its market value based on its current condition. Be sure to search for coins of the same year, mint mark, and condition.
- Check Coin Grading Guides: Coin grading scales, such as the Sheldon Scale (which ranges from Poor (P-1) to Perfect Mint State (MS-70)), can help you estimate your coin’s grade. This is especially important because even a minor surface scratch from cleaning could lower the coin’s grade—and its value.
Special Care for Different Coin Types
Each type of coin—whether silver, copper, or gold—requires unique care to ensure its value is preserved while being cleaned. Different metals react differently to cleaning agents, so understanding how to clean each one is essential.
Silver Coins Cleaning Tips
Silver coins are particularly prone to tarnish due to exposure to air and moisture, but cleaning them needs to be done gently to avoid scratching the surface. A baking soda paste is one of the safest methods:
- Mix baking soda with a little distilled water to form a paste.
- Gently apply the paste to the coin with a soft cloth, avoiding any abrasive scrubbing.
- Rinse thoroughly with distilled water and pat dry.
Avoid harsh chemicals like silver polish, which can strip away natural toning that collectors value.
Copper Coins Cleaning Tips
Copper coins tend to develop a greenish patina over time, which many collectors find desirable. However, if the coin is heavily tarnished or encrusted with dirt, a mild olive oil soak is a safer alternative to using acids:
- Soak the coin in olive oil for a few days or even weeks, depending on the level of tarnish.
- Rinse it with distilled water and dry gently.
Vinegar and other acidic cleaners, while effective, can strip away protective layers of patina and cause irreversible damage to copper coins. These methods should only be used sparingly and with caution.
Gold Coins Cleaning Tips
Gold coins, especially pure gold, rarely tarnish and are best left untouched. Cleaning gold can reduce their value, especially if they have a high collector’s interest. A simple wipe with a soft cloth to remove surface dirt is typically all that’s needed. Avoid all chemical cleaners with gold coins unless advised by a professional.
Myths and Mistakes to Avoid
When it comes to cleaning coins, there are plenty of misconceptions that could lead to costly mistakes. Let’s bust a few myths so you don’t fall into these traps!
Myth 1: Toothbrushes are Great for Scrubbing Coins
While soft-bristled toothbrushes might seem harmless, they can still scratch delicate coin surfaces. Even micro-scratches can reduce a coin’s value, especially for rare pieces. Instead, use lint-free cloths or soft sponges for cleaning.
Myth 2: Strong Chemicals Like Ketchup or Coca-Cola Make Coins Shine
Yes, these household items are acidic and will remove tarnish, but they also strip away the coin’s natural protective layer. Over time, this can cause corrosion, particularly with copper and silver coins. If you want to avoid ruining your coins, steer clear of harsh chemicals and stick to gentler methods like distilled water or baking soda.
Myth 3: The Shinier the Coin, the More Valuable It Is
Many people believe a shiny coin is always worth more, but this couldn’t be further from the truth for collectors. Natural patina and tarnish are highly valued for older coins, as they prove authenticity and age. Over-cleaning or polishing can drastically reduce the appeal and value of a coin, so always consider the coin’s history before cleaning it.
How to Preserve the Value of your Coins
Once your coins are cleaned, it’s important to store them properly to maintain their condition and value. Improper storage can lead to tarnish, corrosion, or scratching, all of which diminish a coin’s worth.
Here’s some reliable tips to follow if you want to preserve the value of your coins:
- Use Coin Holders or Capsules: Store each coin in its own holder to prevent scratches or damage from handling. Coin capsules or 2×2 holders are affordable and widely used by collectors.
- Avoid Moisture: Coins should be kept in a dry environment. Consider placing silica gel packets in your storage area to absorb excess moisture.
- Handle with Care: Always hold coins by the edges to avoid transferring oils from your fingers onto the coin’s surface.
- Long-Term Storage: For long-term storage, place your coins in a temperature-controlled environment. Extreme heat or cold can cause damage over time.
By following these guidelines, you’ll ensure that your coin collection remains in top condition for years to come, whether for display or future resale.
If you are into coins and coin collecting, feel free to browse our wide selection of coin related gifts including necklaces, bracelets, rings, and more.