Expendable mold casting

Expendable mold casting is a generic classification that includes sand, plastic, shell, plaster, and investment (lost-wax technique) moldings. This method of mold die casting involves the use of temporary, nonreusable molds.


Waste molding of plaster
A durable plaster intermediate is often used as a stage toward the production of a bronze sculpture or as a pointing guide for the creation of a carved stone. With the completion of a plaster the work is more durable (if stored indoors) than a clay original which must be kept moist to avoid cracking die casting. With the low cost plaster at hand the expensive work of bronze casting or stone carving may be deferred until a prosperous patron is found, and as such work is considered to be a technical, rather than artistic processes it may even be deferred beyond the lifetime of the artist.

In waste molding die casting a simple and thin plaster mold, reinforced by sisal or burlap, is cast over the original clay mixture. When cured it is then removed from the damp clay, incidentally destroying the fine details in undercuts present in the clay, but which are now captured in the mold. The mold may then at any later time (but only once) be used to cast a plaster positive image, identical to the original clay. The surface of this “plaster” may be further refined and may be painted and waxed to resemble a finished bronze casting.
From:China Manufacturer