The Glass Master by Linda Charles The yellow-white glow from the furnace reflects off the face of the gaffer as he gathers the 3000 degrees Fahrenheit liquid onto his pipe and blows the first bubble. A little more liquid is gathered, the bubble grows a bit bigger. Carefully, the gaffer begins shaping the glass, using water-soaked wood blocks, gravity and centrifugal force to coax it into the desired form. The technique has changed little since Ancient Romans developed the process. Today's gaffer (the "old father" or the eldest, most experienced glass blower) still uses a mixture of silica sand (70 percent), limestone (10 percent) and soda ash (20 percent), with perhaps a dash of potassium chromate (green), iron oxide (brown), or cobalt blue thrown in for color. The Gaffers' Guild at Iowa State is keeping the centuries-old tradition alive, meeting weekly to fashion new works of art. Steve Martin, associate professor of materials science and engineering, is the faculty adviser to the group, but admits his status is that of a "servitor," one who assists the gaffer. "I'm learning right now," he said, noting he has practiced the art for only about a year. Martin started out gathering the glass and learning how to use the pipe. His first assignment was a simple weed pot ("one that isn't good enough for flowers, but good enough for weeds"). Next, he learned to put a shaped lip on the pot, and gradually he worked up to larger, more complex pieces. "You have to slowly build up your skills," he said. "It's a lot like woodworking. You have some very simple, but very different processes." Even the most skilled gaffer sooner or later is reminded that glass often has a will of its own. "You don't always get the shape you intended," Martin said. "Oftentimes, something will happen. The glass can move in ways you don't want it to. Sometimes, the glass tells you what shape it wants to go into." Martin assists gaffers John Rundle, laboratory mechanical technician, and David Martin, professor of materials science and engineering, both of whom "have been blowing glass for 20 years." David Martin started the glass blowing tradition at Iowa State in the mid-1960s when he came to campus. The furnaces, originally in the old ERI Building, today reside in 102 Engineering Annex. While the pieces the Gaffers Guild produces are works of art, the glass blowing process serves as a teaching tool for students in ceramic engineering, Steve Martin noted. For example, students learn about the corrosion, insulation and casting of materials. Students also learn about furnace design -- how to build them and what materials can be used. "It's been a marvelous training facility. Students can see the materials in action," Steve Martin said. The lab also has been popular with school children and other campus visitors. Classes frequently make trips to campus to watch glass blowing demonstrations. Bleachers occupy a permanent section in the room just to handle the crowds. It's also a popular Veishea spot and a source of many demonstration requests. The guild is happy to accommodate nearly any type of group when possible, Martin said. The guild's alumni do their part to keep the practice alive. They have donated everything from the tank blocks (the inner core of the furnace where the glass mixture is melted) to the insulating fire bricks to the wool that covers the crown of the furnace. Right now, the guild is testing whether glass cullett (broken pieces of glass) can be melted down and blown. If successful, an alumnus is ready to donate more to the group. While other colleges and universities may have glass blowing operations, they usually are found in the fine arts departments. "Ours is probably the only one in the engineering department," Martin said. "We're kind of different because we take our engineers and turn them into artists." FURNACES WITHSTAND TEMPERATURES OF 3000 degrees Fahrenheit The glassblower's furnace begins with an inner tank made from thick refractory bricks that can withstand temperatures of up to 3000 degrees Fahrenheit and be in contact with molten glass. Four of these bricks, which are three inches thick, 12 inches tall and 18 inches long, are formed into a tank, with another brick serving as the bottom of the tank. A second layer of bricks that can withstand temperatures up to 2300 degrees Fahrenheit is stacked along the outside of the tank. The top of the furnace is a cement crown covered by four inches of insulating wool. At the very top of the furnace is a burner that fires the glass furnace. Each hour, the furnace uses the same amount of energy used by an average-sized house on a cold winter day. A furnace, which costs from $3,000 to $4,000, lasts about five years before the glass becomes too corrosive and it wears out. _____ contact: Linda Charles, (515) 294-3129 updated: 7-7-95