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Greensand aluminum casting: 12 steps (with pictures)

Aluminum absorbs hydrogen and obviously carbon, so if you just pour what you've just melted down, the inside of the casting will be a mess that may not last long. The temperature of cast aluminum is important, but I have nothing to measure it with, so I skip that step a bit. It's hard for me to emphasize the safety aspect enough here, I can't say everything, remember that the molten aluminum is REALLY HOT. it is so hot that even after 20 minutes of air cooling, by dragging your finger over it just to turn it on, you will get a great burn. (which has the most complete healing …)

It is important to also know that when the sand is exposed to 660c + heat it solidifies, up to about 2.5 cm from the molten aluminum, at that point, it is quite durable . (still reusable later)

  • degass / flux aluminum. I use borax and "sodium-free salt" is poured onto a piece of aluminum plate and wrinkled in a ball. One of them is a flow, and one of them is an exhaust gas. It improves the quality of the cast metal, I still learn how much of it and how it helps. I take a ladle and push the ball to the bottom of the pot, it boils and bubbles and then ends.
  • scoop of garbage. There will be oxides and stuff on top of the aluminum, I made a perforated scoop to remove everything, I'm still not sure if it should be classified as rubbish or scrap.
  • pick pot, pour aluminum into mold. Now I have to apologize, I have no photos. Both the process of picking the pot from my smelter and pouring the aluminum is dangerous and requires both hands and full concentration. If you drop the pot, the reaction forces will send molten aluminum straight up. Make sure your equipment always has a complete lock on the pot as you move and pour it. Make sure your clothes are mixed !, that there is no aluminum lump on you and will end up in your shoe / etc! Aluminum is not hot enough to require heat-reflective clothing, other than that, has lots of safety equipment. My pouring jig is a 2 person installation. You want aluminum to come up "reasonably high" in the riser, a good sinus thing goes well is that the metal comes up in the riser when you pour it. Pouring speed is a consideration, you do not want to erode the sand with the molten metal flow, but you do not want to pour so slowly that the aluminum is almost frozen when it comes to mold details. If the piston sprays a leak stop quietly pouring and put the crucible aside FIRST . Do NOTE dump water everywhere! Use the water sprayer to keep the fire under control (in my case the piston and plywood under it, and with control, it's fine, but the 660c + can reignite it at any time) while the metal cools. Dumping water on molten aluminum (at least 660c) can cause all kinds of nasty things to happen.
  • Pour extra aluminum into your ingots
  • wait. cooling must be done.

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