How to make your own metal casting furnace

Updated April 17, 2017

Metal casting furnaces can be used to melt silver, gold, pewter, aluminium, bronze, copper, tin, brass and other metals. The molten metal can then be poured into moulds to make jewellery, figurines, model, household items or any other shape desired. You can cast metal using a small furnace as a hobby or for profit.

Place the flower pot inside the first large tin. Mark the inside of the tin above the flowerpot's rim. Cut a 5-cm (2-inch) hole in the tin so that the bottom edge of the hole is just above the flowerpot's rim. The flowerpot will become the base of the furnace.

You will want the metal casting furnace to have a cement wall about 5 cm (2 inches) thick. This step will prepare the mould for the concrete. The wooden cylinder should be able to sit on the rim of the flower pot and give you a space of about 5 cm (2 inches) between the tin and the wood. Cover the wood cylinder with aluminium foil. Also cover the dowel with aluminium foil. Insert the dowel through the hole in the side of the tin so that is fits flush against the wooden cylinder.

Mix the furnace cement and pour between the inside wall of the popcorn tin and the wooden cylinder. Allow the cement to harden.

Remove the dowel and the cylinder from the furnace. The aluminium foil should help the wood to slide out easier. Remove all of the aluminium foil. If needed, chisel the hole left by the dowel until it is fully opened to the inside of the furnace.

Bend a steel rod into a handle and weld to the sides of the coffee can. The coffee can and steel handles should be small enough to fit inside the furnace when the lid is closed. This is now your crucible.

To make the lid for the furnace, measure 5 cm (2 inches) from the bottom of the second popcorn tin, and mark a line all the way around. Using the snips, cut through the popcorn tin.

Mix furnace cement and pour it into the now 5-cm (2-inch) deep popcorn tin. Wrap the small tin can in aluminium foil and set it in the centre of the wet cement and press it about 1 inch into the cement. This will make a circular space in the lid that will help with the expanding heat while the furnace is in use. Allow the cement to dry before removing the small tin can and foil.

Bend a steel rod into a handle and weld it to the lid.

To use the furnace, place the crucible inside the furnace. Set the metal to be melted into the crucible. Place the lip on the furnace. The propane burner is ignited and inserted in the side of the furnace. Using heavy gloves, the lid can be removed from the furnace to stir the melting metal or to collect the crucible when it is time to pour the molten metal into the mould.


Handle the furnace, burner and hot metal with caution.

Things You'll Need

  • Flower pot
  • 2 large tins
  • Furnace cement
  • Coffee can
  • Steel rods
  • Propane burner
  • Wooden cylinder
  • 5-cm (2-inch) thick wooden dowel
  • Aluminium foil
  • Tin snips
  • 5-cm (2-inch) diameter tin can
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About the Author

Amanda Dickerson has written hundreds of nonfiction articles on travel, crafts, home decoration, medical conditions and business. Her creative published work includes romance novels and science fiction role-playing games. Dickerson is a registered polysomnography technician and licensed massage therapist.