How to Melt Cast Iron

Save

For those of us who like to do things ourselves, there are a few ways to melt cast iron at home. You can melt a quarter kilo (half a pound) in a microwave, or perhaps you would like to try a homemade furnace for melting 50-300 grams (2 to 12 ounces). Most of the items you will need you can purchase at any hardware or art store. The temperature to melt metal is quite high, so please be sure to protect yourself.

Things You'll Need

  • Dark welding goggles
  • Optional face shield
  • Oven gloves
  • Large flat iron pan to put the mold on
  • Molds (your personal preference to size and shape)
  • Running cold water or five gallon bucket full of cold water
  • Borax
  • Optional heat resistant bricks
  • Gypsum blocks
  • Optional chamotte blocks with optional alumina based concrete
  • Propane gas torch with shorten nozzle
  • Propane gas
  • Optional steel pipe for shortened nozzle
  • Non-graphite crucible
  • Optional Hessian crucible
  • Crucible tongs
  • Thermocouple
  • Build the walls and floor of your refactory furnace with a heat-resistant brick. Gypsum block, cement and chamotte bricks or a high melting point ceramic of silica or alumina are the best choices. The furnace should have a cylindrical shape about 1.5 times the diameter of your crucible. The opening should be at the top with a hole in the center the same size as the torch hole. Leave a hole at the bottom of the wall at a tangential entry for the torch. Make sure it fits exactly.

  • Weigh the metal and fill the crucible. The crucibles that work best with cast iron DO NOT include graphite. A crucible made with Hessian clay works the best. Put the crucible in the furnace.

  • Light the fire using newspaper as kindling between the wall and the crucible. Turn on the gas (torch) slowly and once the paper catches you can turn the torch to full power. If the torch roars loudly, it's fine.

  • Inhale a whiff as the fire burns. If there is a bad smell, then the combustion isn't complete because the walls are too cold. Take the lid off the furnace for a few minutes and put it back on to fix this problem.

  • Use a thermocouple to watch the heat. You want to heat the cast iron to 1300ªC / 2500ªF for fifteen minutes. You will know you have reached this temperature when the crucible's bottom is light yellow, nearly blinding in color.

  • Remove the crucible from the furnace and heat. Add a teaspoon of borax to dissolve all oxides.

  • Pour the molten cast iron metal into the molds you have purchase. Let cool.

Tips & Warnings

  • Preheat meltal molds above 100ªC / 212ª F to remove moisture.
  • The sand in sand molds shouldn't be too wet.
  • Hot cooling objects should not be near tools.
  • Wear shoes you can easily kick off if any molten metal falls on them.
  • Check all the gas couplings after installation and gas canister replacements.
  • Keep all flammables away from the furnace.
  • Do not use asbestos.
  • Always wear dark goggles and face protection.
  • Immediately immerse burns in cold water for a few minutes.

Related Searches

Promoted By Zergnet

Comments

You May Also Like

  • How to Melt Metals at Home

    Learning how to melt metals at home can enable you to complete arts and crafts projects that were previously confined to more...

  • How to Melt Scrap Metal

    Scrap metal accumulates in the workshop of any metal worker, whether you make jewelry, fix cars or build with metal. If you...

  • Do-It-Yourself Silver Recovery

    Silver recovery is done by melting silver objects and creating silver ingots. An ingot is a solid block of precious metal with...

  • Thermal Properties of Cast Iron

    Cast iron is used in a range of applications, from durable cookware to architectural elements to automotive components. Among the benefits of...

Related Searches

Check It Out

22 DIY Ways to Update Your Home on a Small Budget

M
Is DIY in your DNA? Become part of our maker community.
Submit Your Work!