The sand comes off the foundry floor and goes into a machine called a muller, a boxy sheet-metal contraption reminiscent in shape of a combine. "Mullers are strange things," says Pentz fondly, as though he were describing a quirky old car he could never junk. Around this one there wafts a faintly yeasty odor. "You know when you knead dough you're not exactly mixing it. Well, that's what the muller is doing with the sand. When it comes out, it's like dough. It's no longer dry and it's no longer sticky. It's nice and fluffy, all the lumps are gone. It's beautiful." This muller, unlike other models, kneads the sand in two stages. That's why Pentz knew he had to have it. New, it costs $50,000. Pentz tracked this one down one at an auction in Winnipeg. He paid $10,000, plus $1,500 to have it trucked to the foundry.
The sand comes out of the muller and, kneaded just so, rises overhead in buckets to be carried by conveyor across the ceiling to a line of hoppers. Out of the hoppers it falls into wooden forms to be packed by workers around the molds inside. When sand overflows the forms, they go into the molding machines, which come down hard with a furious pneumatic hissing, compacting the sand tight around the mold. Pentz has six molding machines, some of which retail new for up to $37,000. He didn't pay more than $4,500 for any one machine. One he got for $120.
In the past 20 years many American foundries, beset by foreign competition and starved for capital, have died. That has left many idle machines waiting for people like Larry Pentz to come along and make them whole again. The artisan in the second industrial divide, believe Sabel and Piore, possesses great restorative power. He resurrects what the mass economy has long since thrown away. He revives, as Chuck Sabel puts it, "devalued assets."
Today's artisan resurrects more than old machines. He also revives old materials and dated techniques. Pentz Design works in aluminum, a metal that plastic threatened to displace 20 years ago. But lately aluminum has been rediscovered. In an era of high-cost energy, aluminum has often become a lightweight replacement for iron. In an era of high technology, electronic machinery requires adequate shielding from high-frequency noise. Plastic isn't a very good sound insulator. Aluminum is.
Pentz bought one of his furnaces for two-thirds off the going price. The other he built from scratch to his own specifications. The furnaces are electric resistance, not gas. Many foundries make the mistake of using gas, says Pentz. Gas furnaces produce hydrogen, which creates bubbles in the aluminum. Pentz devised his own degassing system, which injects nitrogen into the aluminum to bond with the hydrogen and render it inert. He also developed his own hydrogen-detection system.
Pentz is finicky about keeping the right mix of alloys in the aluminum. Many foundries, he claims, "just melt the aluminum." He adds extra steps to the process, modifying the metal with strontium and titanium boron. He avoids recycled aluminum, knowing it is contaminated with iron.
Pentz's metallurgical education has been an informal one, conducted largely at the shop around the open hearth. He reads trade and academic journals, much of which he passes on as mandatory reading for his foundrymen. "I train them and they train one another." Classes are held one night every other week; ideas are exchanged. "I'm finding now that I learn as much from employees as they do from me," says Pentz. His approach, he says, adds up to "a lot of trial and error."
One customer came to Pentz with a truck scale that kept breaking at 17,000 pounds of pressure. Pentz did research, noting a type of alloy that would make it stronger. The scale he cast broke at 80,000 pounds. "The customer was hoping for a 10% improvement," says Pentz matter-of-factly. "We gave them almost 500%."
* * *
The Chinese invented sand casting 2,500 years ago. Twentieth-century Americans consider the process a dying art. Though their respective applications often do not overlap, sand casting in the past 30 years has been partially superseded by die-cast and injection molding. By those methods molten material is not poured but rather is injected at high pressure into a mold.
The disadvantages of sand casting are clear. Quality varies and the cost per part is high. It demands both dedication and skill.
Conversely, if mastered, sand casting offers compelling advantages: economy, flexibility, and speed. A sand-cast mold costs 5% to 10% what a die-cast or injection mold costs. (A complex injection mold can cost as much as $200,000.) It makes limited runs affordable. Customers can afford to test various configurations of a part because a sand-cast mold can be easily and inexpensively altered while the other molds cannot. To make a change in a die-cast or injection mold usually requires starting over. That is very expensive. Finally, with sand casting a part can move from conception to market in one month. With the other methods it takes six months.
In the artisan's economy, quality assumes more textured meaning than just doing a good job. "Quality really means coming up with creative solutions, not just fewer defective parts," says Michael Piore. "Quality comes from allowing a supplier to stretch his imagination. To do that, a supplier needs to work with a lot of different people. If he is a captive supplier, he's not likely to have as much insight."
A number of Pentz's customers are bunched in the same industries. They manufacture everything from swimming-pool ladders to aircraft parts at tolerances finer than a human hair. Pentz has design input on virtually all the parts it casts. "Sometimes a new customer will tell us they want us to make a box," says Pentz general manager Stewart DeOme. "That's not the way we do business. My first question to them is, What's the function? We like to look at the whole picture. The better we understand what they want us to build, the better job we can do for them."
