Pour your coins into one bowl and fill with cold water until the money is well covered. In the other bowl, pour about 1 teaspoon of baking soda. Dip the toothbrush into the bowl of baking soda and scrub the coins. The baking soda should remove any dirt and grime and won't scratch the metal.
Hydrogen peroxide can prove effective in removing various materials, including organic material. To clean using this method, place your coins in a small plastic container, fill with enough hydrogen peroxide to cover, and soak for 24 hours.
Never use metal polish or acid dip to clean your coins! Using these chemicals will cause abrasions or chemical reactions with the metal, permanently damaging your coin. This damage can never be fixed or undone. Additionally, these chemicals can be caustic and cause injury or even death.
A great way to clean coins without damaging them is by soaking them in isopropyl alcohol and salt. These two ingredients are coarse and acidic, which is an effective way to target built-up dirt. Combine one cup of isopropyl alcohol and two tablespoons of salt in a medium bowl.
Most Cleaning is Destructive: It Can Literally Change the Surface of a Coin. Any cleaning that requires rubbing leaves microscopic scratches. They are not apparent to the naked eye, but a collector will see them. A collector will look for them.
Distilled water is recommended as tap water contains chlorine. The coin is dipped into olive oil which according to Hudgeons, works best for common copper or bronze coins.
Soap and Water - This is generally the only way to clean silvered and silver-plated coins, without damaging the silver. Ammonium - Windex works fine. This will clean the coin without damaging the silver.
Coins that are obviously dirty can be run under water (with a very mild detergent) and left to air dry. A short soak in olive oil may remove unwanted gunge. For cleaning corroded coins the damage is already done, they will forever show pitting into the coin surface. This is as far as anyone should go with cleaning.
Cleaning old coins might seem like a good way to revitalise the appearance of a treasured item, but could in fact reduce a coin's value significantly, and should be avoided. Particularly in the case of old precious metal coins, cleaning them is most definitely not recommended!
Boil 1 1-/4 cups of water, add 2 teaspoons cream of tarter, 2 tablespoons vinegar, and 2 tablespoons salt. Add coins and boil for about 3 minutes or until tarnish is removed. Remove coins from water and dry with a soft cloth.
The vinegar and salt mixture dissolves the outer layer of dirt. Flip the pennies over and wait another 30 seconds. Then remove them, rinse them with water, and dry. Now you have two clean, shiny pennies!
The combination of vinegar (a weak solution of acetic acid), and table salt (sodium chloride) helps to dissolve the copper oxide, and also forms the blue copper(II) ion, which is soluble in water. The penny becomes shiny again!
Take the coins out and sprinkle some baking soda over them; then use a soft-bristled toothbrush to brush them clean. Rinse them out thoroughly with hot water; using tongs or gloves to hold them to avoid burning your fingers. Place them on a soft, cotton towel and leave to air dry.
1. The most important thing NOT to do is clean your coins. Cleaning rare numismatic coins will significantly reduce their value – plain and simple. Although you don't lose much by cleaning a coin which derives value only from its silver content, it's not worth the risk.
You should avoid long term storage with materials that contain polyvinyl chlorides (PVCs), since these chemicals can discolor coins. PVC-containing plastics tend to be flexible and strong, so it's better to choose rigid plastic containers for coins. Avoid storing coins in plastic bags.
Don't clean your coins! Not only does this cut their value by as much as half (or possibly even more), but it will be an immediate deal-breaker for many dealers who would've otherwise wanted to buy your coins if only they were left in their original condition.
Collectible or valuable coins should not be cleaned as cleaning almost always reduces their value and rarely improves their grading. Though it may seem that a bright, shiny coin would be more appealing to coin collectors, the truth is most prefer coins to possess their natural color.