Cleaning and toning Silver Coins
There are a great number of techniques for cleaning silver coins depending on the age, condition, and the purity of the metal. We will discuss the pros and cons of each method going from the simplest to the more advanced. Silver coins can often be spotted because they are mainly black in colour. This is because of the age of the tarnish that can build up over hundreds or even several thousands of years. We would suggest that you start off in this order until you find the method that you like the most. The one thing to remember when cleaning silver coins is that you can always easily put a patina back on them if you over clean them. We will explain how to do this later in this guide, but first let’s look at some ways to clean the coins. Remember to always rinse the coins off with water after cleaning and dry with a soft cloth.
- Using the “spit and foil method”, quite simply this is a very simple method that is very popular with collectors. You simply spit into a piece of Aluminium foil shiny side facing the coin and rub the coin in it between your fingertips. It can be a little abrasive but is hugely simple, and will often leave a nice dark background on the coins and bring the raised detail out nicely.
- Baking soda and foil, exactly the same principal as the “spit and foil method” except instead of spit simply use a little water with some baking soda (also called bicarbonate of soda).
- The “foil, baking soda and hot water method”, another old favourite that can be quite successful. Simply line a bowl with some Aluminium foil, shiny side facing inwards then cover the foil with boiling water. For some reason it seems to work slightly better if the foil is a little crinkled and its edges are higher than the level of the boiling water you pour into it. Add a teaspoon or two of Baking Soda (also called bicarbonate of soda). And you will see it starts to fizz in the hot water. Simply add your tarnished coins and turn them a few times until you are pleased with the result. This method is great to use on good quality Silver coins that are not to tarnished. But you will see that is does struggle with some of the ancient Silver coins. We would suggest maybe trying it twice, and if it has not achieved the desired result it is likely that it never will.
- Lemon Juice method, simply leave the Silver coins in some Lemon juice for up to a day. Again this method can be reasonably successful but really does depend on just how tarnished the coin is along with the purity of the metal. You can improve this method by adding an old “iron nail” to the mix. However we would recommend that you only try this for a maximum of about an hour, and then simply soak in Lemon Juice again if you have not reached the desired effect.
- Shop purchased Silver Cleaners; we really have seen a range of results using these. The major issue with using them is the fact once again that they do really struggle with being much use on the lower quality extremely tarnished kinds of coins. Something to note here is that if you use baking soda methods after using some Silver dips it can actually turn your coins black again for some reason.
- Without a doubt the best way to get an amazing bright finish on ancient Silver coins is to use Sulphuric Acid. Sulphuric acid does not in any way react with Silver therefore it will do absolutely no damage to the coins whatsoever. You need to do this in a well-ventilated area, wear rubber gloves and appropriate safety equipment including goggles and a mask. Use an old heatproof bowl and add boiling water to it. Wrap the coins individually in Aluminium foil shiny side facing in and drop them into the hot water. At arms length then pour in some Sulphuric acid, you wont need too much and will get used to how much to add after you have used this method several times. There will be a reaction with the aluminium and the hot water, and some smoke will come off the solution for several minutes. After a few minutes the reaction will cease and you can remove the coins with a pair of long nosed pliers. Rinse them under a tap, unwrap them then rub them between your fingers with baking soda. Sulphuric acid can be purchased from most hardware stores as it is commonly used as a drain cleaner.
If ever you want to make your silver coins dark again there is a real easy way to put a patina back on them. You might do this if you find it more pleasing; perhaps you have cleaned them until the point that they are amazingly bright. Or now they have been cleaned properly you want to darken the relief and just use some foil on them to show some of the features. All you need to do is purchase some “liver of Sulphur”. You can get this from some craft shops or simply buy it online. Add a small amount to some water and then dip the coins in it until the desired result is achieved. The only adverse effect is a strong smell of eggs, so we would always recommend doing this in a well-ventilated area or in the garden.
How clean you want your silver coins is really down to preference, a lot of people love them to show all the details and be as clean as they can get them. Others much prefer them to stay deep black. And of coarse there are those who want something in the middle. Well this guide allows you to achieve any desired finish from slightly clean to brightly clean. But remember if you ever want them to look tarnished again a little liver of sulphur will achieve this in less than 60 seconds so Silver is far easier to work with cleaning wise than bronze or other alloys.