Sunday, July 3, 2011

Creating an investment.

As with all metal clay, silver metal clay shrinks when its fired and the organic binder burns away, depending on the type and brand of clay the shrinkage varies from 8% - 30%. So obviously this is something that needs to be considered, especially when making rings or bezels (out of paper clay sheeting). One way to ensure the bezel or ring does not shrink beyond the size required is to create a replica stone out of a casting investment.  

  • Firstly you need to make a mould of the stone or for rings you can buy purpose made moulds for the size of ring you require.
  • As above this can be done by pushing the stones into polymer clay.
  • Remove the stone and then bake the polymer clay.

  • The powdered Investment is mixed with water to create a paste.
  • The paste is poured into the mould and allowed to dry.

  • Then the investment in removed from the mould and placed into the dried silver clay piece that is ready to be fired.
  • Once the piece is fired and cooled, the investment can be removed by dissolving it in water.
  • Now, in theory, the bezel or ring should be the required size.

The investment and ring after firing!

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