Lead has a relatively low melting point, so it is ideal for casting into shapes of your choosing. There are varied applications for melting and reshaping lead; it is ideal for creating custom-sized fishing weights, and it is also perfect for creating oddly-shaped weights to adjust the weight of a hobby car or plane. Learning how to melt lead is a straightforward process, but one that should be conducted with extreme caution and diligence.
1. Set up your vessel and heating source. Lead should be melted in a well ventilated, fire safe area, as it can create dangerous fumes and present a fire hazard if not handled properly. The best heating source is a hand held oxygen-acetaline torch for melting amounts of lead. As a vessel, you will need to use a heavy metal container. Do not use a pot used for food preparation.
2. Put the lead into the vessel. Add more lead to the vessel than you think you will need, as some of it will re-solidify onto the sides of the vessel when pouring.
3. Heat the lead until it melts. Turn on your heat source and adjust the heat to its highest setting, if applicable. Apply the heat as directly to the lead as possible. Lead melts at a temperature of 328 degrees Celsius (621 degrees Fahrenheit), so it will take time to melt a large amount of lead. Since most lead you use will not be pure, you will have impurities ('dross') float to the top. Use a metal spoon, preferably aluminum, to scrape off dross, and place dross in a separate container. To purify the molten lead, drop it a small amount of wax (old candle pieces) to 'flux' - be aware you may have some flames but just let them burn off. Stir pot and scrape sides and bottom to get all impurities to rise to the surface - flux again before pouring lead into mold.
4. Pour the molten lead into its mold. Once the lead has melted, turn off the heat source and prepare to pour it into whatever mold you have prepared. You will have to work quickly because the lead will cool and solidify quickly. Pick up your vessel with heat-resistant gloves, swirling it gently to keep air bubbles from forming in the lead. Pour the lead into the mold. Be careful to avoid placing your hands directly above the vessel, as hot gases will be escaping and present a burn risk.
5. Let the lead return to a safe temperature. After pouring the lead, do not disturb it for at least 10 minutes. This will ensure that the metal is cool enough to handle safely.
6. Clean up any spills. If the lead has spilled or overflowed, it will harden onto the surface it spilled on. It will not form a very strong bond, however, so you can dislodge it with a chisel or a flat-head screwdriver.