How It's Made: Lost Wax Casting Part 2 - Casting

January 30, 2018

How It's Made: Lost Wax Casting Part 2 - Casting

Photography by Ryan Leggett

Casting courtesy of Jena Hounshell Casting

 

In Part 1 of our 3-part series, we carved a ring from a block of wax to be cast into precious metal.

Today for Part 2, I’ll take you through the steps of molding this wax model and then casting it in gold.


Casting the Wax Model in Gold

Spruing the Wax Ring Model to a Rubber Base - How a Ring is Made - Corey Egan

 

The wax ring is attached to a rubber base to create a mold. A wax rod called a sprue connects the two. This will become the channel through which molten gold flows into the ring. 

The Wax Model Sprued to Flask Base - How a Ring is Made - Corey Egan

A metal flask is secured onto the rubber base. Then investment plaster is poured into the cylinder and over the wax model. We pour slow to avoid causing air bubbles in the plaster. This part always reminds me of pouring pancakes.

 

Pouring Investment into the Flask - How a Ring is Made - Corey Egan
Pouring Investment into the Flask - How a Ring is Made - Corey Egan

 



The flask goes into a vacuum chamber that shakes out any remaining air bubbles. We let the plaster harden and then remove the rubber base.

 

Flasks in the Kiln - How a Ring is Made - Corey Egan

The flask is heated overnight in an electric kiln to bake the plaster until it’s fully cured. As the heat rises our wax melts away, leaving a ring-shaped cavity inside of the plaster.

Now it’s time to melt some gold!

 

Gold Casting Grain the Crucible - How a Ring is Made - Corey Egan

Gold Casting Grain in the Crucible - How a Ring is Made - Corey Egan

The casting grain is weighed and placed into the crucible to melt. We need enough metal to fill our whole ring, plus some extra for the sprue and button. A healthy casting has a cute button on the bottom (you'll see!)

Using a Torch to Melt Down Gold - How a Ring is Made - Corey Egan

Our flask gets loaded next to our crucible in a spring loaded centrifugal caster. We light the torch and begin to melt down the casting grain. Watching this flame and the molten gold dance feels a bit like magic.

Using a Torch to Melt Down Gold - How a Ring is Made - Corey Egan

Using a Torch to Melt Gold - How a Ring is Made - Corey Egan
Molten Gold in the Crucible - How a Ring is Made - Corey Egan

 

Centrifugal Casting - How a Ring is Made - Corey Egan

When the gold has reached the right temperature, we remove the flame. Then we pull a lever that sends our crucible and flask spinning in circles. The molten metal is forced out of the crucible and into the flask using centrifugal force.

Gold Button on the Bottom of the Casting - How a Ring is Made - Corey Egan


When the machine stops spinning, we can see the flask is now filled with gold. Here is that cute little button at the bottom of our casting.

Quenching the Flask - How a Ring is Made - Corey Egan


We submerge the flask in water to dissolve away the investment plaster. A solid gold ring is all that remains!

Freshly Cast Gold Ring - How a Ring is Made - Corey Egan

Freshly Cast Gold Ring
The ring is now made of gold but it’s far from refined. See how we clean, polish and set our diamond in Part 3 of our How It's Made series!

 

Continue Read - Lost Wax Casting Part 1 - Carving
Continue Reading - Lost Wax Casting Part 3 - Finishing