Until some Nosy Parker of a scientist comes up with proof to the contrary, air is still lighter than water—and a whole industry continues to thrive on this bit of elementary physics. It all started with the inner tube, and the end is not yet in sight. Inflatable objects range from water toys that resemble a zooful of colorful animals to station wagon mattresses to small boats for hunters and fishermen. Because they can be deflated when not in use, they take up very little storage space, whether in an automobile or a closet. They are lightweight, and if properly cared for will wear better and last longer than foam-composition equipment or toys.
Most good inflatables now stress safety features such as dual air chambers that are completely independent of each other and which inflate and seal separately. If a stopper should pop off accidentally or a puncture occur in one air chamber, the other air chamber will support the float until safety is reached or repairs can be made. Many seams are double laminated. Valves on some of the better equipment are designed so that they allow air to enter freely but keep it from escaping. Caps are generally added to each valve as an extra precaution.
The composition of most inflatables, whether boats, mattresses or toys, is either vinyl plastic or rubberized fabric. Inexpensive vinyl inflatables are sometimes made of reused vinyl which docs not hold up well under wear. A good virgin vinyl generally runs from 12 to 14 gauge (weight and thickness). Manufacturers, however, are not required to mark the gauge of vinyl. The best way to tell the difference between vinyls is to feel and compare the thickness and weight; an inexpensive, reused vinyl is generally much thinner and lighter.
Rubberized fabric is durable and more difficult to puncture than vinyl. It is made of heavy-duty cotton duck or nylon that has been impregnated with liquid rubber. This seals the fabric, making it watertight. Mattresses and tubes made of rubberized fabric do not stick together from the inside when deflated as old rubber inner tubes do when they are stored away-for the winter. The fabric is treated and powdered on the inside to prevent sticking.
Parents and nonswimmers should keep in mind that many inflatables, as well as other floating devices, are not life preservers, unless they are specifically labeled as such. Most floating objects are primarily for fun and comfort.
A wide assortment of pumps and inflators to take the work out of blowing up inflatable equipment is available this season. There are hand pumps, foot pumps, built-in pumps, replaceable CO2 cartridges and even an inflator that plugs into an auto dashboard. These windsavers range in price from 70� to $13.
The three inflators sketched above are from the Hirsch-Weis Canvas Company in Portland, Ore. The accordion-pleated, cone-shaped pump on top ($5) operates by hand or foot. Manufactured in Germany, it is made of red rubber and utilizes a coil spring for fast, easy operation. The tip will fit metal valves, and it comes with an adapter to fit rubber valves. The center pump is called an all-purpose Sports-Lung ($1.35). It is a hand-operated bellows. It is metal-reinforced on both sides, and the bellows is made of rubberized blue cloth. The rubber hose will fit any air mattress. The bottom inflator is called a Lectro-Flate air pump ($13). It eliminates all the work of hand, foot or mouth inflation because it plugs into the lighter socket on an auto dashboard. It will inflate anything, from inflatable cushions and decoys to station wagon mattresses, backyard swimming pools and boats. It comes with a rubber adapter hose for metal valves and operates on 12 volts.
The Voit Rubber Company has a hand-operated Inflato-Bag Air Pump (70�) which is made of heavy plastic and is designed to trap a large volume of air through light hand pressure. Air moves through an attached tube that fits onto all oversize valves. Voit also makes a Lung Pump ($2) of heavy-gauge vinyl that measures about 12 inches by 6 inches and is almost flat. It operates with coil-spring action for fast inflation by foot or hand. Compressed CO2 gas cylinders or cartridges are also available for rapid inflation. They can be obtained from the Gokey Company, St. Paul (four for $1.20, postpaid).
The large Voit two-man utility boat ($50) is designed for hunters, fishermen, skin divers and vacationers. It is 8� feet long, 4� feet wide and 20 inches deep and is made of blue double-gauge extra-heavy-duty laminated vinyl. Three separate air chambers plus a concealed inner tube give it maximum safety; either of the two main chambers is supposed to keep two adults and a 30-pound motor afloat. Each air chamber has a one-way valve that lets air in but prevents it from escaping. To deflate, a small tool is inserted into the valve and is locked there until all the air has been removed. The boat comes equipped with a sea anchor, tow rope, tie-on ropes for oars, repair kit with extra deflating tools and a heavy-duty bag-type inflator. Diagrams for installing seat and motor attachments also come with the boat. Thousands of these little boats are owned by hunters and fishermen because of their usefulness and because of the ease with which they can be transported and stored. Skin divers who carry a lot of heavy gear should put an inflatable mattress in the boat to protect the craft from sharp spears and equipment.
The Neptune Kayak ($150) is a two-seater sports boat made by Metzler of West Germany for Healthways, Los Angeles. It is 6 feet long and has five air chambers. Bright red in color, it is made of extra-heavy-duty rubberized canvas. Best of all, it will fold up into a shoulder carrying bag.