I have heard of a method of making Cold Bronze, but it is a little different:
In this, bronze particles are suspended in a resin matrix and sprayed 1/16 of an inch thick onto the surface of a fiberglass mold, created from a rubber mold taken from the original clay sculpture. Because the resin rises to the surface as the bronze particles "dry" during the spraying, the resin acts as a protector.
Using cold-bronze instead of cast bronze also keeps production costs down, but there are trade-offs for the savings. The cold-bronze work won't last for the several thousand years expected of solid bronze. But it ought to hold up for close to 100 years.
Does anyone else have any experience?