Foundry

The foundry

The cart for all tools and accessories. The top contains green sand.

The main crucible

About our machine

• Details: Custom made foundry. Built from small propane tank and lined with furnace cement
• Fuel: Propane
• Location: on a cart with the Rolling Workbenches
• For use outside ONLY
• This tool requires a safety checkout

Safety

• ONLY USE OUTSIDE. Ensure fumes will not enter the building. Do not stand down-wind from the fumes.
• Wear appropriate clothing for hot work
  • All cotton or natural fiber clothing. SYNTHETIC CLOTHING WILL MELT TO YOUR SKIN.
  • Leather boots or shoes are preferred. NO OPEN TOED SHOES.
• Wear appropriate safety gear
  • Shaded goggles or lens. Always wear when looking at glowing objects to protect from intense IR light that can burn your eyes.
  • Thick leather gloves. These should be heavier than welding gloves. Note - the gloves do not permit you to directly hold hot metal, and only serve as a temporary barrier.
  • Leather apron and chaps to protect against splashing metal.
• Treat all metal like it is hot metal! You can't tell just by looking if a piece of metal is hot enough to burn you. Always use the tongs for moving metal until it has fully cooled down.
• USE EXTREME CAUTION WHEN WORKING WITH ZINC AND CHROME ALLOYS. Use additional ventilation or wear a respiratory.
  • Zinc fumes can cause "metal fume ever", leading to severe chills and many health problems.
  • Chrome fumes can result in respiratory irritation and other severe health problems.
• Check hoses and fittings for leaks before operating. Use soapy water and look for bubbles at all connections and valves
• Prepare for hot metal and open flames!
  • Limit how much you travel with hot metal. Set up all equipment so it is close by and easy to pick up.
  • Have fire extinguisher on hand. Know where the nearest water source is.
  • Have bucket of water to cool down tools and molten metals.
  • Ensure any potentially flammable objects are at least 30 feet away.
  • Prepare a spot to put down hot objects, use fire bricks, sand, or items that can withstand 2000F.

Igniting the Foundry

1. Adjust the flow valve so it is fully closed
2. Light a stick or small scrap of paper and place inside empty foundry
3. Slowly crack open the valve on the tank, then open at least 3 full turns
4. Slowly open the valve on the regulator until flame ignites
5. Turn valve up to 30 psi
6. Turn on air assist
7. Ensure flame is stable
8. Put items you want to melt inside crucible
9. Place crucible inside
10. Place a small piece of firebrick on the rim of the foundry (this will leave a small gap when the lid is on)
11. Place the plug in the lid's hole, then place lid on top of foundry. This will allow heat to build up.

Melting

1. Allow sufficient time for crucible to warm up (approximately 10 minutes)
2. Occasionally inspect contents of crucible.
   1. Put on goggles
   2. Carefully remove plug from the lid to look into crucible
   3. Use a metal rod to push on the material to check if it is liquid
   4. If it is not, close the plug and put the hot tool down somewhere safe.
3. When melt is molten, use a metal rod to stir the contents. This helps mix up impurities and allow them to reach the surface.
4. Gently scoop surface-level "slag" and undesirable oxides out of molten metal and scrap into a steel container. Repeat this process multiple times until metal looks clean

Casting

1. Before pulling out crucible, ensure the following conditions are met:
   1. the path to your mold is unobstructed
   2. the tools necessary for pouring are handy and easy to pick up quickly and safely
   3. there is a place to set the crucible down when you are switching between tools
   4. you can go through these steps quickly without interruption. time is critical once the crucible is out and the metal is cooling, delays will result in pre-mature cooling and a bad pour
   5. you have a back-up mold in case the main mold breaks. you still need to empty the crucible if things go wrong, so pour remaining into an ingot mold.
2. Remove the crucible using tongs
3. Place on insulated pad
4. Grab tools for pouring the crucible
5. Lift crucible by hinge pins
6. Place hook into loop on bottom of crucible
7. Bring crucible over to mold and pour

Teardown

When you are done, ensure the following conditions are met:

1. Close valve for propane tank.
2. Be on Fire Watch for 1 hour after the flame has been put out. Stray embers or unseen hot metal could start a fire well after the flame has gone out.
3. Wait 2 hours after the flame has put out for the Foundry to cool down enough to go back in storage.
4. Ensure all tools and items have cooled down and can be stored safely back on the cart.
5. Return fire extinguisher to its stored location.