How Is Lace Cast Into Metal?


One of the questions I get asked most often about my work is, "How is it made?  It's lace...but it's metal?  How do you even do that?"  Well, wonder no more, because here's a step-by-step explanation of my process!

 

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The pieces begin—like so much lace—with plain cotton thread.

 

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The motifs are then soaked in wax.  This both stiffens the lace and makes it non-porous.

 

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From there, sprue waxes are attached...

 

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...and the pieces are arranged in a tree and attached to a rubber base.  A steel canister is then placed around the pieces.

 

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After that, the mold-making material (called investment) is mixed...

 

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...the air bubbles are vacuumed out...

 

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...and the investment is poured into the canister, around the pieces.

 

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After the investment has set, the rubber bottom is removed, and the canister is placed in a kiln, where the temperature rises to 1250°F (almost 700°C) over the course of 7-8 hours.  This melts out the wax and destroys the lace, leaving a hollow that the molten metal can later fill.

 

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Once the burn-out cycle is complete, the (still hot) canister is loaded into a centrifugal casting machine, and the machine (being spring-loaded) is wound up.

 

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The metal is placed in a ceramic crucible and melted with a torch...

 

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...then the machine arm is released, and the centrifugal force pushes the molten metal into the mold.

 

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Once the machine has come to a stop, the canister is removed and quenched in water.  This breaks/dissolves the investment mold...

 

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...and the casting can be retrieved.

 

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Now it's time for bench work!  The castings are cut off the sprues with a jeweler's saw...

 

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...after which the rest of the investment is scrubbed off, and the pieces are put in a mild acid bath (called a pickle) to remove oxidation.

 

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From there, the rough edges are filed and sanded...

 

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...and earring posts, jump rings, and anything else are soldered on and assembled...

 

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...turning the castings into functional pieces of jewelry.

 

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Now it's time for finishing!  The pieces are burnished with a brass brush to make them sparkle...

 

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...rolled in a tumbler to give them just the right amount of shine...

 

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...and then given a final cleaning with ammonia to brighten them up.

 

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Ta da!