In Thurston James’ second book, he tackles the subject of molding and casting for prop makers in more detail. The Prop Builder’s Molding & Casting Handbook
Though written in 1989, the methods described in this book still hold true today. Though the range of materials we can use today have grown dramatically, they remain improvements and new formulations to older materials whose predecessors can be found in this book.
It remains one of the most widely recommended books for molding and casting props because of the unique niche it fills. It describes the most common materials and methods used in props shops and by hobbyists; these materials are used because of their cost, ease of use, availability, and proven results. Books on molding and casting for manufacturing and industry are more focused on specific or specialized materials, and they aim for a level of consistency and cost efficiency which the prop artisan would never possibly need. Shaving a tenth of a cent off the cost of a casting makes a difference if you are casting ten thousand pieces, but it will be impossible to notice if you are only making ten.
James seems to have had an epiphany in shop safety between this book and the last, as he now presents clear and accurate safety precautions in the beginning of the book, and continues to reiterate them throughout. In his Theatre Props Handbook, safety precautions were nearly nonexistent.
The book does a good job of covering the generalities of mold making and casting. It discusses the model and its preparation, and defines a number of necessary terms, such as undercuts, release agents, mother molds and the like. It describes the considerations of making a mold of your specific piece, and breaks the various molding materials and casting agents into categories. In a way, it describes the process of choosing your materials in an almost flowchart-like manner. If you know what your model looks like, and you know what kind of properties and appearance your castings need, then you can narrow your choices of mold material and casting material down to a few choices. In the book, he describes over thirty of these material choices.
The bulk of the book is used to guide you through the specifics of working with each of these materials. Specifically, he talks about plaster, alginate, latex rubber, and silicone rubber (RTV) mold-making. The casting materials he describes include latex, neoprene, papier-mâché, Celastic, fiberglass (GRP), hot melts (such as wax, plasticine, hot melt glue and hot melt rubber, breakaway glass, thermosets (specifically polyester resin), water-extendable polyester, and urethane. He also has a section on casting with hardware store products, like caulk, autobody filler, water putty, and several others. Finally, the last section of the book describes vacuum forming and how to construct a vacuum forming machine.
