The basic process of casting is simple enough to do at home; molten soda cans and packed sand molds will do a reasonable job. The Renfrew works operated at an entirely different scale, of course, and made cast iron parts rather than cast aluminum. And while the process was simple, the craftsmanship was anything but. The patternmakers stand out the most; with all the woodworking skills of fine cabinetmakers, they turned pine and mahogany into the complex patterns needed to form the molds from casting sand. The least defect would be reflected in the casting, so special care was paid to finishing the wood, and the patternmakers needed to be clever indeed to make some of the multipart patterns required for complex parts.
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Watching the film, I was struck by the thought that as low-tech as foundry operations seem from our vantage point, the products that came from them were anything but. First, the film was made in 1953, right about the time that both the world’s first commercial nuclear power plant, Calder Hall in England, and the world’s first nuclear submarine, the USS Nautilus, were being built using B&W boilers. Casting fittings and boilers for nuclear plants is cutting edge stuff, even if it starts with sand and molten metal.
From the article:
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