Many an outdoorsman, casting an eye at gathering thunderheads and envisioning sodden clothes and sopping sleeping bags, has mumbled incantations to the leaden skies. Well, campers, mumble no more; help is here in the form of a "wonder" laminate called Gore-Tex Fabric.
This answer to an outdoorsman's prayer began to be formulated on an October evening in 1969 when Robert Gore, a Maryland chemist, tried to see how far he could stretch a handful of a resin called PTFE. That's polytetrafluoroethylene to those in the know, Teflon to the rest of us. Gore and his industrialist father Wilbert soon discovered that by any name PTFE has unusual characteristics when it's stretched into very thin sheets. Today's Gore-Tex is a film .001 of an inch thick that weighs only one-half ounce per square yard, and every square inch of it has nine billion pores. Each pore is large enough to allow water vapor to pass through but too small for water in liquid form to seep through. Hence, body vapor can escape but raindrops can't get in. Just like real skin, Gore-Tex breathes but is waterproof.
Because the membranelike sheets are extremely flexible and delicate, for rugged outdoor use they are sandwiched between layers of nylon, polyester or any other common outerwear fabric. With this added protection Gore-Tex can go just about anywhere—mountaintops, ocean swells, even outer space (NASA plans to use the material in space suits for its shuttle-flight personnel).
A manufacturer needing Gore-Texed cloth calls in the particulars (type of material, color, etc.) to W. L. Gore & Associates, Inc. in Elkton, Md. where the specified fabric is laminated to the PTFE film and then sent to the manufacturer. This process makes the final product—tent, jacket, sleeping bag, gaiters—more expensive than conventional gear, but to campers and hikers who have remained comfortable through rain and sleet and dark of night it's worth the extra dollars.
At first it wasn't so easy to convince manufacturers that the Gores had, indeed, built a better mousetrap. "When I first went out to sell Gore-Tex," says Joe Tanner, who has been with the project almost from the start, "I had to convince the experts. 'Wolf had been cried too many times before. Many firms would ask, 'Why isn't North Face using it, or why isn't Sierra Designs buying?' "
Then one day Tanner approached Early Winters, a small outdoor-equipment company in Seattle, and found the firm's president, Bill Nicolai, a willing listener. Nicolai ordered some Gore-Tex laminate, had it cut and sewn into a tent and, with designer Bill Edwards, tested it in a driving rain. "The walls of the tent stayed absolutely dry," says Nicolai. "We knew that this was our big chance."
When the new tents proved to be an instant hit, Early Winters was off and running. "We sold three or four hundred in a matter of weeks," says Nicolai. "The public was ready and so were we. We took the money from the first tents and bought more sewing machines so that we could make more tents. We knew that clothing wouldn't be far behind."
That was in 1976, a year in which 10,000 yards of Gore-Tex Fabric was sold, most of it to Early Winters. Since then, sales have increased dramatically.
Though the material seems to be taking the outdoor scene by storm, so to speak, it does have some limitations. "It is not a miracle thing," warns Eric Sanford, director of Liberty Bell Alpine Tours of Mazama, Wash., a group specializing in climbing trips. "Gore-Tex does not make an end-all fabric. But, to date, it's the best in the field."
One drawback is that, to be truly waterproof, every seam in a Gore-Tex garment must be sealed where the sewing needle punches holes in the fabric. Because the sealer used is both toxic and flammable, many manufacturers don't do their own sealing. Instead, each of their products comes with a tube of the gluelike stuff, and a buyer must do the messy job himself. W. L. Gore & Associates, Inc. hopes to eliminate this incovenience by encouraging manufacturers to use either an ultrasonic or high-frequency weld on seams.
Finally, the tiny pores in the laminate can become clogged by oils from the skin, sun creams or cooking products, rendering the cloth temporarily non-water-proof. A good washing with a mild soap opens up the pores.
But these are only minor inconveniences for the outdoorsman who has discovered that his Gore-Tex down jacket is not only windproof but also sheds water, leaving the down stuffing dry, fluffy and thermally active. And when a camper can bed down under dripping trees with the assurance of spending a comfortable night, you know that the Gores' invention is truly a "wonder" material. Says a Marmot Mountain Works spokesman after spending the night in one of the company's "Gopher" Gore-Tex down bags, "It seems strange to wake up after sleeping out of doors on the bare ground and see everything wet and dewy around you and yet feel warm and perfectly dry inside a sleeping bag."