How to Cast a Bronze Cannon
- 1). Carve a block of jeweler's wax into the shape of a cannon. A typical decorative cannon is around 3 feet long with a 10-inch diameter, so buy a block of jeweler's wax at least this size. Once you have the wax, use a large knife to carve the basic profile of the cannon. The finished piece will resemble the wax shape exactly, so remove any imperfections in the wax. Use a file to smooth the wax into the rounded shape of a cannon. Now use 400-grit sandpaper to smooth the wax out completely. Jeweler's wax is hard, so it won't deform easily under the pressure of a file or sandpaper.
- 2). Cover the wax in fireproof plaster once it is fully finished. Plaster of paris is a good type of plaster to use and comes in powder form. Mix the plaster with water according to the manufacturer's instructions. Then fill a large container with it. You will need at least a gallon of plaster for even a medium-sized cannon. Place the wax mold into the plaster, and carefully pour plaster over the wax mold until it is covered completely. Allow a thick hard shell of plaster to form around the wax.
- 3). Loosen the plaster mold carefully from the container and remove the mold. Drill two 1/8-inch holes into the "butt" of the cannon plaster mold and heat the mold with a blowtorch or in a furnace. The wax will melt and you can pour it out. Be sure you pour all of the wax out of the plaster mold.
- 4). Heat the bronze to melting point in a large graphite crucible. Metal and crucibles can be found at foundries, blacksmith supply shops and blacksmithing websites, such as Budget Casting Supply or Atlas Bronze. The amount of bronze needed will vary depending on the size of your furnace. Heat the bronze in a gas furnace to its melting point of 1,700 degrees Fahrenheit. Using a pair of long steel tongs, carry the crucible to the plaster mold and pour into one of the holes you have drilled. Only pour the bronze into one of the holes; the other hole will allow air to escape while the mold is filling with bronze. Now leave to cool overnight.
- 5). Break the plaster shell and polish the cannon with 600-grit sandpaper until it has an even sheen all over.
