Last week, I posted pics from Angelica Sandoval’s Aluminum Casting. This week, it’s BRONZE in Mark Cowardin’s class on NOVEMBER 10! How do you know it’s bronze?
Preparations for BRONZE Casting; note the GREEN color of the flame indicates (MATERIAL/ CHEMISTRYGEEK ALERT!) that it’s Bronze.
Bronze is comprised of COPPER and TIN. Tin makes the copper harder, more durable as it was discovered many millenia ago during the Bronze Age. However, it’s the Copper that gives the furnace flame it’s signature green hue.
The Crucible of liquid bronze is lifted from the furnace.Care has to be taken…this bronze is HOT STUFF.Cowardin supervises the students carrying the crucible (above) and instructs them on how it should be poured (Below)
The Bronze pour Crew, with their teacher, Mark Cowardin (far right)
One of the truly exciting experiences for JCCC students in Sculpture is the casting process.
This intricate, multifold process starts with an idea, which then the student makes a “positive” of using microcrystalline wax. Once made, a wax “sprue” (channel for the metal) is attached. The entire solid piece of wax is then dipped multiple times into a silica slurry, which builds up a “ceramic shell” around the wax. After the shell has dried, it is fired and the wax is steamed/ melted out, leaving a void in which a metal is then poured, such as aluminum or bronze. The shell is then chipped away, leaving the “positive” metal piece, whereby the sprue is removed and the sculpture is cleaned.
Angelica stands with her Sculpture students donning all the necessary safety gear in preparation for a “pour”.Before removing the crucible from the furnace, Angelica skims a mucky “slag” or waste from the top. Leaving dirty slag can cause ugly pitting in castings.(Above) Angelica Sandoval and a student lift a crucible full of molten aluminum out of the furnace prior to casting.
(Above) Molten aluminum is carefully poured into the ceramic shells, which are packed in sand to prevent cracking.
The crucible is attached to a hoist/ crane which makes lifting the heavy crucible more manageable.