< A BRIEF GUIDE TO BLENDING
CREATING A CAST WAX PATTERN
Permanent patterns (artist’s sculptures for casting), constructed in materials like PLASTER and RESIN cannot be directly incorporated into investment moulds. The founder instead uses a [rubber] reproduction mould to create a cast wax copy of the master pattern. Wax is used to fill the resulting ‘negative impression’ mould, solidifying as a positive image reproduction. In the foundry, this copy of the artist’s pattern is usually referred to as a WAX PATTERN.
The wax pattern is a near exact copy of the artist’s design – near exact because however well made, some of the materials used in the process, like wax and rubber, are subject to a degree of shrinkage. As a result the wax pattern will always be slightly smaller than the master pattern on which it was based. This should not unduly concern the artist, because the difference in measurement between the wax and the master pattern is not usually discernable by eye.
There are a number of methods the founder can use to obtain wax patterns from reproduction moulds. The exact methods used are variable according to the individual preferences of each foundry workshop, and the particular challenges of the job in hand. The procedures described in this section of the chapter therefore only provide a generalised overview of how a wax pattern is produced from a reproduction mould.
CASTING WAXES FROM MOULDS >
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