Duct Tape
ON FEBRUARY 10, 2003, with government intelligence agencies indicating a high risk of terrorist attacks, the Department of Homeland Security advised Americans to prepare by keeping emergency supplies on hand. The requisites included food and water, a first-aid kit, and, in case of a biological or chemical attack, plastic sheeting and duct tape.
Across the country, people rushed to stock up. The Pressure Sensitive Tape Council, a trade organization issued a press release announcing that its 26 members had “mobilized to meet the increased demand for duct tape.”
For many Americans, the call to use duct tape as a defense against nerve gas or microbes was both alarming and faintly comical, for in recent years duct tape has become an item of homerepair kitsch. In The New York Times , John Leland described the tape as “national shorthand for a job done almost right.” For many Americans, duct tape represents the quick and easy way to fix things. It is the Great Enabler of home repair, allowing people to patch or mend things, if only temporarily, with a minimum of time, skill, and effort.
The first duct-tape users were not reluctant handymen hastily shoring up sagging gutters with a prayer and a dozen yards of tape, then hurrying back to the couch before the secondhalf kickoff. The original olive-drab version of the tape was developed during World War II for a specific purpose: The military needed a tough, waterproof adhesive tape to seal ammunition cases and other containers.
At Permacell, a division of Johnson & Johnson, a research team led by John Denoye and Bill Gross set to work on a cloth tape that would be similar to surgical tape but tougher and water-resistant. They came up with a strip of cottonmesh cloth coated with a polyurethane sealant on one side (making it waterproof and allowing the tape to be peeled off the roll) and a thick coating of rubberbased adhesive on the other. According to an undocumented tradition, military personnel called the stuff duck tape, either because water rolled off it or because of the layer of cotton “duck” cloth that formed its base. The amphibious vehicle known as the “duck” (from DUKV, the manufacturer’s classification code) may also have something to do with the name. Its use on ammunition cases led to another name, gun tape.
What made duck tape unique was its combination of a strong pressure-sensitive adhesive with a backing that could be torn by hand. Among countless applications, soldiers used it to mend boots, patch holes in tents, and strap equipment to jeeps and tanks. During the postwar housing boom ex-GIs found that duck tape was handy for sealing joints and insulation on ventilation and air-conditioning ducts. It changed from khaki to the familiar silvery gray and was christened, or rechristened, duct tape . Many people still call it duck tape, presumably because the two phrases sound almost identical. In the 1980s the Cleveland-based firm of Manco, Inc., capitalized on the persistence of the original term by marketing its tape under the registered trademark Duck tape.
Not all duct tape is the same. The cheaper brands tend to be thinner, with a more dilute adhesive and a backing of vinyl or polyethylene laminate on a loose-woven fabric scrim. HVAC professionals wouldn’t touch the duct tape sold in most hardware stores, and manufacturers of consumer-grade duct tape would never suggest that you use the stuff on actual ducts. HVAC-grade tape, which can sell for more than $20 a roll, is thicker and has a greater tensile strength (since its backing has more threads per inch) as well as a powerful, often pungentsmelling adhesive.
The versatility of duct tape is legendary. Astronauts in the crippled Apollo 13 space capsule used duct tape to improvise a lifesaving carbon dioxide filter. Duct tape is standard equipment on the space shuttle and the International Space Station. According to a testimonial on the Manco Web site, mechanics once used duct tape to temporarily patch a small hole in the windshield of a passenger jet.
A technical note from the Pressure Sensitive Tape Council cheerfully observes that duct tape is a “favorite tape of criminals and keeps turning up in the evidence of crime and murder scenes,” an application that can be seen in Martin Scorsese’s The King of Comedy when Sandra Bernhard fulfills many people’s fondest wish by wrapping Jerry Lewis in the stuff. In the bayous of Louisiana and Mississippi, duct tape is an indispensable tool of alligator hunters, who use it to wrap a gator’s mouth and keep it from biting. Special varieties of duct tape are manufactured for race cars and for use by U.S. government agencies. It may or may not be reassuring to know that there is also a grade of duct tape made specifically for use in nuclear reactors.
Duct tape was directly inspired by surgical tape, but an equally valid claim to its parenthood belongs to masking tape and cellophane tape, both developed in the 1920s by Richard Drew of 3M. Drew first created a paper-backed masking tape to protect parts of a surface during painting. He then spent a year finding a way to apply an adhesive to a new, moistureproof type of cellophane that had been developed by DuPont. The result was the familiar and versatile “Scotch” tape. Masking tape and cellophane tape are designed to be removed easily and to leave little residue, so they use a weak adhesive that dries out and loses its stickiness quickly. They are prob- ably responsible for more jury-rigged repair jobs than duct tape.
Despite all the jokes, more often than not duct tape gets the job done. Just don’t use it on ducts. Studies by scientists at Lawrence Berkeley National Laboratory in California suggest that even top-of-the-line duct tapes are poor at sealing ducts. In the late 1990s members of LBNL’s Environmental Energy Technologies Division studied duct leakage as a major source of energy loss in residential buildings. In “accelerated aging” experiments conducted at extreme temperature and pressure conditions, they tested 19 common types of duct sealant, including various grades of standard duct tape, plastic- and metal-backed tapes, aerosol sealants, and mastic (a paste-like cement). Clear polyester tapes with acrylic adhesives, in spite of their puny tensile strength, maintained their seals far longer than duct tape. Partly because of the Berkeley study, a California program that provides tax credits for building energy-efficient structures now prohibits the use of duct tape as a sealant, as does the Environmental Protection Agency’s Energy Star program. In response, the industry is developing improved grades of duct tape that will meet new energysaving standards.
In the end, though, duct tape’s inadequacy as a duct sealant may be only proper. After all, using duct tape for its intended purpose runs counter to the spirit of ingenuity, improvisation, and expediency that lies at the very heart of its appeal.