Sculptor, Kristan Marvell, talks about bronze casting, which he describes as an ancient process that hasn’t changed much.
The bronze casting process requires a fire to heat the metal, which typically uses gas or electricity. In the old days the fire used wood with a bellows, or whatever could produce enough heat to melt the bronze.
The bronze is heated within a ceramic container, called a crucible, until it gets hot enough to melt.
Melting temperature starts around 1800 degrees and the pouring temperature is around 2100 degrees.
The molten bronze is poured into an empty investment (a mold). Today’s investment is called ceramic shell, which is primarily a glass material. The investment is made by starting with a wax object that will be made into bronze and then encasing the wax in this ceramic shell material. Then the wax is burned away, leaving an empty investment, which is the bronze mold.
The empty investments are put into a kiln to make them hot so the metal will flow better in the pouring process.
When the molten bronze is at the right temperature, it is poured into the empty investment (the mold) until it’s full, and then allowed to cool overnight.
The next day the investment material is hammered away to leave the desired bronze object.
Sponsor: NONPROFIT FIRE, Fundraising for Nonprofits
Sponsor: PJ MURALS, We Paint Your World Beautiful
Sponsor: SKYWORKS MARKETING, Performance Advertising