Step 6:  Melting wax out of ceramic shell mold and then pouring hot bronze into the empty mold 

(Please scroll down until you come to "Next Step")

d7img003s.JPG (9555 bytes)

Before melting the wax out of the ceramic shell mold, the bottom of the sprue cup is removed with a grinder.

d7img002s.JPG (10351 bytes)

The owl is then put into an oven.    In this oven the wax will melt and the ceramic shell will harden so that it is very similar to porcelain.   The owl is positioned with the sprue cup facing down, so that when the oven is heated, the melted wax will drain out.   Wax that doesn't drain will burn.

d7img001s.JPG (11400 bytes)

d8img034s.JPG (8616 bytes)

d8img033s.JPG (10478 bytes)

The empty, extremely hot ceramic shell molds are removed from the oven, by workers wearing protective clothing.

d8img032s.JPG (8272 bytes)

d8img030s.JPG (9492 bytes)

These hot molds are placed in a sand pit with the sprue cup facing up.  Now, empty, the cup becomes a funnel.  What were wax sprues, attaching the cup to the owl, are now empty channels for the melted bronze to flow down into the owl form.

d8img029s.JPG (10800 bytes)

In a nearby furnace, the bronze has already been melted.   It is in a heat resistant container called a crucible.  It takes two strong and coordinated people to lift the full crucible up with a special four handled clamp.   Careful attention is given to the temperature of the molten bronze before the pouring captain gives orders to pour the glowing liquid metal into the still hot ceramic mold.

d8img028s.JPG (10871 bytes)

d8img027s.JPG (11260 bytes)

Depending on the thickness of what the wax was, the molten bronze is heated to between 1,800 and 2,150 degrees Fahrenheit before being poured.   Thinner forms are poured at hotter temperatures.

d8img026s.JPG (9477 bytes)

The bronze is now cooling in these filled molds.  Everything that was wax, is now bronze!

Next Step

return to welcome page

click here to return to "How to Make a Sculpture" Index Page

return to welcome page

click here to return to Welcome Page