Cardboard contains many possibilities

If you want to build a boat to ride in, an easy chair to sit in, or even a scale-model skyscraper that reaches to the ceiling, think "cardboard." It's hard to find a more adaptable, less expensive, or more available building material.

More than 90 percent of all products in the United States are shipped in corrugated-paper boxes. Mattresses come in them. So do refrigerators, dishwashers, bicycles, and televisions.

You've played with corrugated-cardboard boxes before. Perhaps you've studied them and discovered the secret of their sturdiness.

Corrugated boxes have at least three layers: two flat sheets (the "liners") with a wavy layer ("fluting") glued in between. It took a while for people to figure out what corrugated paper was good for. The first corrugated material was used as a sweatband lining for tall men's hats in Victorian England. That was in 1856. In 1871, corrugated paper was being used to protect kerosene- lamp chimneys and glass. By the end of the 1800s, liners had been added and the material was being used to make boxes. Corrugated boxes began replacing heavy, expensive wooden crates.

According to one prominent economist, the corrugated box is one of recent history's greatest, most overlooked inventions. "It's really an incredible product that we never think about," Russell Roberts of Washington University told National Public Radio in 1999.

It's a great, overlooked building material, too. Most corrugated is easy to cut, requiring only determination and a strong pair of scissors. A box knife or small handsaw makes easy work of thicker corrugated. (But you'll need to ask a grown-up to help you.)

Corrugated projects to try

* Throughout the spring and summer, kids and grown-ups build kayaks, long barges, model paddle-wheelers, and other fanciful boats. They enter them in The Great Cardboard Boat Regatta, a series of events held in cities across the United States.

* Schoolteacher Michael Lipinski helps his fifth- and sixth-graders build a model city of skyscrapers at the Erving (Mass.) Elementary School. They use empty appliance boxes provided by a local store.

* You may have seen the episode of "Zoom," the PBS-TV show, in which New York teenager Nick Young designed and built a lounge chair from sheets of corrugated.

Richard Archer, now retired, was a professor of art and design at Southern Illinois University in Carbondale. He organized the first cardboard boat regatta in 1974 as a student problem-solving exercise. "I was looking for a project that seemed impossible," he says.

About 10 cardboard-boat regattas are held each year. Entrants create an impressive array of watercraft. Some are comical, made to look like everything from cars to cows to tanks. Boats in a team competition may be more than 100 feet long. Many are built by parents and children working together.

Not all of the boats are seaworthy. Those that don't float very well are eligible for the "Titanic Award." But the fact that most of them can be raced over a short course is a testament, once again, to corrugated's versatility. (Hint: Five or six coats of enamel floor paint or polyurethane deck finish vastly improves the boats' water-resistance.)

"I know that for every boat that makes it to a race," Mr. Archer says, "the people working on it have solved a host of problems. What length should the boat be? What width? How high should the side walls be?" This kind of problem-solving builds teamwork as well as design skills.

The first year a regatta is held, Archer says, about half the boats sink slowly as the cardboard absorbs water. (All sailors must wear life jackets.) The next year, only about one-third of the boats end up sinking as entrants learn from their mistakes (or from cardboard-boat-construction workshops).

Create your own skyscraper

If boatbuilding isn't your thing, maybe try to design a city. Every other year, students at the Erving Elementary School build model skyscrapers out of corrugated. They look very realistic.

Before starting construction, pupils study how cities grow, using a computer program (SimCity 2000) that simulates the city-building process.

The computer screen, of course, only offers images in two dimensions. In order to grasp the three-dimensional aspects of city buildings, each student crafts his or her own building.

First, students must obtain "building permits" from the teacher. To do this, they submit sketches of buildings they studied in class, as well as a detailed drawing of an original building design. They must include a list of specifications: how tall the building will be, how wide, and so on.

In order to make sure that the buildings look as though they belong together, they must be in proportion. Everybody must use the same scale: one inch on the model equals 10 feet. This allows the model structures to be impressively large without going through the ceiling. Toy vehicles of about the same scale (Matchbox or Hot Wheels cars) can be put at the base of the buildings and look realistic.

A 60-story building winds up being roughly 60 inches tall (five feet). Students are told not to build any higher than they can reach (without using a ladder).

The sides of the building are cut from corrugated board and glued to a substructure made from 1-by-1-inch wooden strips. (A hot-glue gun makes quick work of this, but regular white glue is fine, too.)

To achieve a high degree of realism, a computer is used to design the "skin" of the buildings. Erving students use the "Draw" module of AppleWorks, but similar results are possible using other graphics programs.

Using a computer, it's easy to experiment with different "looks." Once a full-page panel is designed and approved, it's a simple matter to print it out and photocopy it. The white edges of the copies are cut off, and the copies are applied to the exposed cardboard of the building using glue sticks.

This method eliminates the tedious work of hand-drawing or painting hundreds of windows and other building details. This also guarantees a uniform, professional appearance. (Hint: Don't design panels that use lots of black. That uses up a lot of toner in the photocopier.) Students add custom touches: Markers are used to color the "skin"; towers are added - even construction-paper swimming pools on the roofs.

The whole project takes several days to complete. When everyone is finished, the buildings are arranged together to form a city. The students are proud of their work. Some take the buildings home to display in their bedrooms.

By Ross Atkin

Corrugated's secret lies in the inner, wavy layer. The shape (and glue) adds lots of strength. Freight shipped in corrugated boxes was often refused by railroads in the 1890s. It took a federal order in 1903 to establish the boxes as a valid way to ship items. Welcome to Cardboard City

Fifth- and sixth-graders at the Erving (Mass.) Elementary School take city planning into their own hands. They design and build a scale-model city. It's a popular assignment, and one that requires lots of time and energy. Don't try this project, Michael Lipinski advises fellow teachers, unless you are: willing to devote lots of class time to it; have access to lots of large pieces of cardboard (see below); are handy with basic cutting tools, staplers, glue guns; and can tolerate a messy classroom for days at a time.

For more details, skyscraper 'window' templates, and more see the school's website: www.fi.edu/ fellows/fellow3/apr99/simcity2000/models.htm

The school uses cardboard donated by a local business. For this and other major cardboard projects (boats, chairs - we've seen photos of cardboard sled competitions, too), check with appliance stores and other merchants that receive products shipped in large boxes.

You can also look in the Yellow Pages under "Paper Products" for companies that will sell corrugated sheets. Recycling bins are also a good source. (Ask first.)

Sail away in a boxy boat

SO, ARE YOU READY to try making your own cardboard boat? You will definitely need a grown-up's enthusiastic cooperation to design, build, and test one. Here are some construction tips from the pros to get you started:

* To get clean folds in corrugated cardboard, make a creasing tool. Buy a large metal screw eye at a hardware store. Buy a big one, so the loop will compress the cardboard without cutting into it. Look for a screw eye that's about two inches in diameter, in other words. Drill a hole in the end of a wooden handle (a section of old broomstick, perhaps), and screw in the screw eye. Use this lollipop-shaped tool and a sturdy straightedge (a board, maybe) to crease the cardboard before you fold it. Nice bends are the result.

* Carpenter's glue, sold in hardware and home-improvement stores, is the preferred adhesive. School-type white glues are OK for corrugated constructions that will stay dry, but weaker white glues are likely to wash out in water.

* The best way to seal joints is with silicone caulking compounds. (Again, this is for boat construction.) Silicone adhesives come in squeeze tubes as well as in canisters that require a caulking gun to apply. (Read and follow all safety directions when using this kind of caulk.)

* Use nuts and bolts (not screws) to hold layers of corrugated board together. Use thin-shafted carriage bolts with wide washers (called "fender washers") at either end. The washers improve the bolt's surface-holding area. Be careful that protruding bolt ends don't create a hazard.

Hint: Cardboard boats are very light, and do not displace much water. In other words, they don't sink into the water much. Experienced cardboard boaters know to make the hulls of their craft flat-bottomed, rather than V-shaped. Flat-bottomed cardboard boats are much less likely to tip over. Also, boaters should sit directly on the bottom of the boat to lower its center of gravity and further improve stability.

Be careful! Always wear a life jacket.

For more information about the Great Cardboard Boat Regatta, visit their website: www.gcbr.com One teen's comfy paper chair

As Nick Young proved on an episode of "Zoom" last year (PBS-TV, check local listings), corrugated cardboard is strong enough to make a chair. The New York City teen designed and built a one-of-a-kind lounge chair (pictured at right) with the help of his architect father. He first made a "crush tester" to see how much weight the corrugated could support. That helped him design a strong chair. He used big sheets of new cardboard, bought from a supplier, for the project.

(c) Copyright 2001. The Christian Science Monitor