Metal casting has been used for centuries to create formed objects such as weapons, keys, bullets, jewellery, and coins. Casting was especially important for the creation of coins and currency before the invention of the mint. In ancient times, coins were typically cast from materials with a low melting point, such as tin, lead, or sand. With the right equipment and preparation, coin enthusiasts can cast their own coins out of lead or other metals right at home.
Create the mould for your coin by using the moulding material to take an impression of the "prototype" coin (or coins) you wish to use as a model. Specialised plasters and moulding rubbers are available commercially, and are fairly simple to use, typically requiring casters to merely impress the coin's sides into the drying mould, or to pour the moulding material around the coin and separate the mould after drying. Carefully follow the instructions included in the moulding set, creating an impression of the coin's side in the material.
Set the mould aside to dry or cool.
Carefully crack the mould open along the fissure line; this will give you two halves of a cast of your coin. Alternatively, you may choose to purchase a precast mould from which to cast your lead coins.
Place the metal pot over the heat source and place the lead into the pot. Turn the heat on to 650 Fahrenheit, or to the highest setting if using a propane stove or flame heater. Lead is fairly easy to melt, and this process can even be performed over a small propane camping stove.
Continue to apply heat, carefully stirring, until the lead is completely molten. All impurities in the lead will rise to the surface.
Skim off any impurities in the lead with a long handled fork and set aside. Add a modest amount of candle wax to the pot and stir it before again using the fork to skim off any additional impurities that appear.
Gently heat the mould by holding it over the heat source with pliers for 2-5 minutes.
Hold the mould over the pot and carefully ladle the molten lead into the cast. Allow any excess to run off into the pot.
Open the mould over the bucket of water and use a non-metal tool (such as a wooden stick or dowel) to carefully tap the mould until the newly cast coin or coins fall into the water. Floating a sponge in the bucket of water will act as a "landing pad" that reduces excessive splashing or steam.
Repeat this process to create more coins, making sure to add more candle wax and skim the surface again every 15-20 minutes.
Wrapping the melting pot in aluminium foil will help it to heat up faster.
Lead fumes can be very toxic and potentially deadly. Always handle molten lead in a very well-ventilated area or outside. Do not under any circumstances add water to the melting pot or allow anything wet to come in contact with the molten lead. Even a small amount of water in the pot can cause a steam explosion. When adding candle wax to the melting pot, it may flare up into flames momentarily. This is normal, just take care to control the flames. Always use safety gear when handling molten metals and exposed flames. Safety goggles, leather or heatproof gloves, an apron, long sleeves and trousers, and a face mask are all recommended when handling molten lead.