Copper wire is a commodity. Because metal prices have risen sharply over the years, even a base metal like copper has value. As copper is a heat conductor, the metal is widely used as electrical wire and building wire. Jewellery hobbyists can buy scrap copper wire, melt it down, pour it into bars and reuse the metal to make new wire or sheet. If possible, remove any protective coating, such as plastic, that might be on copper wire when you purchase it from a scrapyard. This process ensures you aren't melting it off and creating fumes that may be toxic.
Stack one to three fire bricks into a base on which you will balance the crucible. A crucible is a cup that can resist heat. It often is lined with a material that doesn't melt, such as ceramic.
Twist copper wire into small coils or bundles, tucking the ends in so that coils don't unfurl, and put them into the crucible.
Open the gas to turn on the oxyacetylene torch. Spark the flint striker to light the torch. Turn the gas on high and adjust the oxygen to get a hot flame.
Place the flame over top the copper wire to start the melting process. Move the torch back and forth to heat the copper evenly.
Put approximately 1/2 to 1 tsp of borax into the copper after it starts to melt to keep oxidisation from forming.
Focus the flame over the copper, gently shaking the crucible to mix the wire and redistribute pieces that are still whole. Heat the copper until it liquefies, about 5 minutes, depending on how thick the wire is and how much you are melting.
Concentrate the flame on the pouring lip of the crucible so that it turns red hot to aid the pouring process. Pour the copper into the first bar using one fluid motion. Repeat for the other bars. If the copper begins to thicken, reheat following the steps above and pour subsequent bars.
Before melting your copper wire, try to ensure the coils are uniform in size or weight so that all pieces melt in more or less the same amount of time. Include larger coils of thin copper wire and smaller coils of thick copper wire.
Consider wearing protective gloves when heating large quantities of copper. Ensure long hair is tied back, and avoid wearing loosefitting clothing (e.g. sleeves) that make get in the way when heating and pouring the metal.