The Direct Lost Wax Method

Basic metal casting, technically known as the direct lost wax method, is quite simple. To begin with, a positive image of the object that is ultimately to be reproduced in bronze is fashioned in wax to create what is called the “master model.”

A wet cast is then formed around the master model which, when it hardens, forms the “master mold.” The cast picks up the negative image of the master model so that now there are a positive (model) and negative (mold) of the same image. This image transfer from the positive to its negative (and back again) provides the logical key to bronze casting, no matter how complex the process becomes.

Molten bronze is then poured into the mold, transferring the mold negative image to a metal positive. The bronze cools, the mold is shattered and, finally, a faithful reproduction of the master model now emerges miraculously in stunning bronze.

There are, however, two problems with this direct lost wax method. First, the physical properties of bronze do not allow large solid casting, thus limiting the technology of the ancient craftsmen to the reproduction of small items such as votive tablets, arrow heads, small weapons, or ornaments.

And, secondly, both the master model (the positive image in wax) and master mold (the negative image of the clay cast) are destroyed in the process of bronze casting. The wax is melted to make way for the bronze; and the cast is shattered to free the metal image.

Each bronze produced by direct casting is therefore unique; and serial reproduction is impossible. Thus the ancient craftsman was obliged by the direct casting method to produce both a fresh master model and new master mold for each bronze copy.

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