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Is forming metal coins (specifically ones with copper, nickel, and zinc) possible with these steps:

  1. Carve a sheet of sodium chloride so that it is big but not too big and so that the design sticks out of the sheet of sodium chloride.

  2. Cut the sodium chloride so that you have 1 big circle with the design

  3. Form a mold out of clay from the sodium chloride design

  4. Scale it down without losing detail using a carving machine(instead of hand carving like with the sodium chloride) that carves the design on each side on a separate piece of clay(which is much easier to carve than sodium chloride).

  5. Once the clay is in the leather hard stage(usually takes about a day) put a piece of clay of uniform thickness and hardness around each side of the coin so that you can hand carve the rim(make sure the rim is not too wide) This will make there be space for the metal

  6. Once the rim is in the leather hard stage attach the 2 sides to a base, again made out of clay

  7. Fire the clay

  8. Smelt the metal

  9. pour the metal into the clay mold

  10. get the metal coin out of the clay mold

  11. Heat the metal again but don't melt it

  12. Cool the hot metal

  13. Wash and dry the metal

  14. reuse the clay mold so that you don't have to start all over again from hand carving sodium chloride but rather only from step 8 which is smelting the metal

One of my big concerns of this process is that a copper, nickel, zinc mixture might melt the clay as soon as the metal is poured in but at the same time I don't want to use a metal that you can bend with the pressure from your hand like you can with aluminum.

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  • $\begingroup$ Melt not likely- more likely cause disintegration due to thermal shock. Why not use a green sand process- Wikipedia describes Sand Casting reasonably well. $\endgroup$
    – user2617804
    Aug 12, 2014 at 7:03
  • $\begingroup$ so your saying that even with molten metal at thousands of degrees that the clay mold won't melt? I mean clay, yes it does have a high melting point and so does sodium chloride but those are not nearly as high as with a copper, nickel, zinc mixture, especially sodium chloride compared to metal. $\endgroup$
    – Caters
    Aug 12, 2014 at 7:06
  • $\begingroup$ and I was thinking of starting with a sodium chloride cast because you can carve it reasonably well(its mohs hardness is only 2.5) and going to a clay mold because clay is much more flexible than sodium chloride(If you try to bend sodium chloride it just breaks) and then finally metal which is hard like sodium chloride but flexible like clay because the majority if not all coins are made of a metal of some sort and not clay or an ionic compound(both of which dissolve in water) $\endgroup$
    – Caters
    Aug 12, 2014 at 7:12
  • $\begingroup$ Sodium Chloride isn't a bad idea but it will be hard to shape to get much detail. Wood would be better for detail. You're title should be a question. Another element is that the ration of mold (clay in this case) to casting material is typical large, the process happens quickly and its protected by a layer of steam- all that protects the mold from damage. Need to consider expansion of the metal when casting and other factors. $\endgroup$
    – user2617804
    Aug 12, 2014 at 7:50
  • $\begingroup$ Why would Sodium Chloride be hard to shape to get much detail if it is hard and you can carve it easily. It seems like if it is hard and you can carve it easily than it would be easier to get the fine details. $\endgroup$
    – Caters
    Aug 12, 2014 at 7:58

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