If you've been considering a small project for your boat, but you really don't want the trouble of cutting and finishing wood, then plastic is for you. It's perfect for chart racks, storage racks and a hundred other projects. It's particularly good for objects that might make an area look cluttered if you used a 'solid' material. Clear plastic is one way to have your protection and not see it, too.

Among the relatively easy projects you could tackle are hinged plastic spray shields to protect an instrument panel on a flying bridge, chart holders for the cabin, towel racks in the head, and condiment shelves in the galley.

Acrylic plastic is probably the most overlooked and underrated material suitable for the amateur craftsman. From a cost standpoint, it is much less expensive than teak or mahogany. Plastic sheets are readily available (unlike good wood), and can be cut, drilled, sanded and bent using simple tools. Best of all, the ability that's required to produce a professional appearance is far less than you'd need to make even a simple wooden bookend.

There are several types of plastic available. The most common goes under the product brand name of Plexiglas. Plexiglas G is a general-purpose acrylic sheeting suitable for most small projects. Plexiglas K is a much tougher sheet intended for window glazing and other uses where strength is a major factor. Type G is the easiest to use and can be glued easily. Type K doesn't bend as well, is more difficult to glue, and should be used only if strength is critical, such as in a skylight that might be stepped upon.

Another brand of acrylic sheet sometimes found in plastic supply shops is Lexan, the so-called space-age material that is tough enough to stop bullets. The price alone is enough to stop most people, but it is even stronger than Plexiglas K. Ask your supplier about the various strengths as you plan your project before deciding on a thickness. Beyond 1/4-inch, you're starting to get into sizes that are difficult to handle in the home workshop. Smaller sizes should be suitable for most projects.

The first step is to produce a good pattern or template. Depending upon the project, use light cardboard or stiff paper to duplicate the item you want. Make any bends that are planned, and place the template where the finished item will be installed to check for clearances and suitability. Once you're satisfied, transfer the template to the paper covering the acrylic sheet using a pencil or pen.

There are several ways to cut acrylic sheet. A coping saw with a fine blade works well, but power tools make the project much simpler. For long straight cuts, a circular saw fitted with a cross-cut blade intended for veneers or plywood is best. Make sure that it has at least six teeth per inch. For shorter straight cuts or curves, use a saber saw with a metal-cutting blade. For acrylics of 3/16-inch to 1/4-inch, a 14-tooth blade is best. For thinner plastics, use a 32-tooth blade. Don't ever use a wood-cutting saw blade because it will shatter the plastic edges.

Leave the paper covering on the plastic while cutting. If you must remove it for any reason, use masking tape to protect the bare plastic from scratches and also to keep the saw from clogging. Clamp the plastic sheet firmly, and don't force the saw. Slow and easy pressure will keep the cut clean and chip-free.

Drilling Acrylic
Here again, a gentle pressure will produce perfect holes, while force-feeding will cause chips or might even crack the plastic. Conventional metal bits in a hand drill will work satisfactorily, but the best method is to use a variable speed electric drill equipped with drill bits intended for plastic. The plastic must be clamped firmly because it will tend to climb the drill bit. Use a slow speed of 1000 to 1500 rpm and let the drill pull itself down. When the tip starts to pass through the other side, go slowly to make a neat exit.

Edge Finishing
The rough-cut plastic edges will appear white and powdery, but they can be finished to several different styles. By sanding the edge with progressively finer grits, you can achieve a satin finish, which is the finish you'll need when gluing the edges together. Be sure to use a block for your sandpaper to avoid rounding edges that will be glued.

To achieve a transparent edge, con-tinue sanding with wet or dry sandpaper down to a fineness of 600 grit. Buff it with rubbing compound or toothpaste using a soft cloth or flannel buffing wheel, and finish off with a wax for a professional-looking edge. When you're finished, you can remove the protective paper from the acrylic.

Bending Acrylic
For most projects, you won't need a plastic sheet thicker than 1/4-inch, which is the maximum that can be bent on a strip heater. Strip heaters are just what they sound like ' a belt-like 110-volt heating element that will uniformly soften the plastic sheet. They are available at all plastic supply shops and many hardware stores for about $12. You'll have to build a base out of scrap plywood, but directions are included, and it's a simple task.

Remove the paper from both sides of the plastic and mark the planned bend using a wax pencil on the top surface. With the heating element plugged in, lay the marked bend line directly above the center of the heating element. It shouldn't touch the element, but should be about 1/8-inch above it. You should experiment with scrap acrylic before you risk your actual project, because the bending takes some experience. Unless you are using very thin sheeting, you'll find that the bend will not be as crisp as you might expect from cardboard or paper. Instead, it will be a rounded curve that may alter your dimensions, so try some practice bends first. The plastic will seem to wilt and soften when it is hot enough to bend. For 1/8-inch sheet, it should take five to six minutes, while 1/4-inch sheet will take 12 to 15 minutes, depending on the air temperature. Wearing gloves, pick up the heated plastic and bend it gently and steadily to the angle you want. Keep the heated edge on the outside of the bend, if possible, and don't force the bend. Attempting to bend before the plastic is softened will cause it to craze and fracture in the bend area.

For perfect corners, a scrap of clean smooth wood can be used as a mold over which the plastic is bent. The soft plastic will be impressionable, so make sure there are no sharp edges or splinters on the mold. Remember, plastic is flammable and should never be heated over an open flame or in an oven. The strip heater is the best way to bend acrylic.

Cementing Acrylic
You can make an excellent joint using either a thickened cement or a liquid solvent, available in plastic shops. The solvent dries quicker, is somewhat easier to use, and is nearly as strong as the plastic sheet. The cement takes longer to dry because it's stronger and recommended for exterior applications. Both are transparent when dry, although the cement is less likely to leave tiny visible bubbles in the joint because it can be squeezed out completely.

The edges to be joined should be satin-finished but not polished. Remove the paper from the area around the joint, but leave it on elsewhere for protection. With the solvent, the pieces should be taped or clamped together. Using a solvent brush, an eyedropper, or a special solvent applicator, apply small amounts of solvent to the joint. By capillary action, the solvent will flow into and along the joint, drying within a few minutes. Full strength requires overnight drying, but for most purposes, the joint is finished in minutes.

The cement is applied to one surface, and then the two pieces are clamped together. Make sure to squeeze the pieces tightly to eliminate bubbles and get the maximum strength.

Attaching Acrylics
The finished item can be attached in a number of ways. The most common method is to use bolts or screws, but because plastic can produce internal stresses, you must be careful not to force it into place. Don't bend it to fit a curved bulkhead, for example. Use round-head screws or bolts only, and don't counter-sink the plastic to accept flatheads, even though they might look better. The wedge-shaped hole will cause stresses, and you'll soon have a broken piece of plastic. When tightening the screws, take them all up snugly and then back off a quarter-turn.

Painting Acrylic
If you want to paint the item, use a Krylon or acrylic-based lacquer designed for outdoor use. A spray can is the easiest method, since brush strokes are often visible. If it's possible, also spray paint the underside of the plastic. This will leave a smooth-appearing surface.

If it all sounds simple, it really is. Just remember to practice on scrap material first, and you'll soon be able to make distinctive and useful additions to your boat.

Duffel Duty
The new Explorer from West Marine really meets the needs of boaters. It has a rugged PVC waterproof pan bottom so you can put the duffel down on a wet dock and not have to live in wet clothes for the weekend. And if you've ever watched from a commuter airline seat as the ground crew drops your duffel bag in a puddle during baggage loading, you'll know why you want a waterproof bottom.
The secret to the usefulness of the Explorer is the end pockets. One is designed for wet clothes, with a ventilated end panel and an expandable waterproof bag that extends into the center compartment.

The other end has multiple pockets inside the end flap, including a padded neoprene holder for a cell phone, plus a security snap for your keys. On the outside, a zippered pocket will hold anything from airline tickets to magazines, and a long lengthwise pocket will easily hold deck shoes, sandals or a jacket.

The Weekend version ($60), which is the middle size of three Explorers, is plenty big enough at 28 inches by 11 inches by 11 inches for a long charter or cruise. Contact West Marine, Dept. BW, P.O. Box 50070, Watsonville, CA 95077; (800) BOATING; www.westmarine.com.

January 2002