Building a Better Boat Fender


Building a Better Boat Fender

Frank Lanier

My main problem with boat fenders is that they appear to violate the cardinal rule of cruising: any object you bring on the boat should serve at least two purposes (the way your crewmate’s favorite yellow shirt makes a great Q flag). A fender, however, does only one job-cushion the blow between the hull and something hard-and then it swallows up valuable lazarette or anchor locker space when it’s not required.

Recently facing a shortage of fenders, I came upon a temporary substitute-heavy-duty dry bags. Filled with air, these simple roll-top bags work just like inflatable fenders. The main difference is that inflatable PVC fenders like the ones weve tested have urethane plastic bladders inside the outer shell (usually PVC), enabling them to hold air longer and be better protected against puncture.

Someone industrious, of course, could insert an inflatable urethane liner into a more rugged, welded PVC dry bag, and achieve the same result. The outer bag could be easily fitted with web eyes for securing drop lines. When the dry-bag/fenders arent being used dockside, they can keep your off-season clothes dry in the forepeak, safeguard your wardrobe on the Colorado River, carry clean laundry in the dinghy, . . . and so on.

Durability is a question. Im not sure how long a conventional dry bag will hold up when used as a fender. If they are constructed with a material similar to that used to make the inflatable fenders featured in our recent test, they should last several years. I wouldn't be surprised if a non-marine fabricator already sells a thick bag suited for this new purpose. During a recent trip in Idaho, I was impressed by the heavy gauge material used in the dry-bags for whitewater rafters. The ones I saw were made byJacks Plastic Welding, a custom dry-bag maker located in New Mexico.

So here’s a challenge: Is there perhaps another fender design that could help it serve two distinct purposes? Or are there more uses for a conventional fender than first meet the eye? (I’ve thought of several since first writing this-buoying an anchor for later recovery, keeping chain catenary off a sensitive bottom, rolling a heavy dinghy ashore, etc.).

Building a Better Boat Fender

Jack’s Plastic Welding (

And for those who’d rather just stick with the tried-and-true, heres a DIY approach to more conventional fenders.

DIY Fender Board

Fender boards are almost a necessity when docking against pilings because without them, no matter how you position and secure your boat and fenders, movement of tide and boat will displace the position of the fenders relative to the piles. The result is dinged topsides.

Fender boards, designed to ride outboard of two fenders, protect a much larger section of topsides much more effectively.

The simplest form of fender board is adequate for most needs. All that is needed is a 3- to 4-foot length of 2 x 4, 2x 6, or 2×8. As a guide, Id start a t 2×4 for a 20-foot boat, 2×6 for a 30-foot boat, and 2×8 for a 40-foot boat.

On a larger boat, you may want to use a slightly longer board, perhaps up to 6 feet long. Anything longer than that, however, is likely to take two people to handle, and be a nuisance to store.

Just go the nearest lumber supplier and get normal dimension lumber, which may be any variety of softwood. Make sure that it doesn’t have any large knots in the middle of the board, which might make it cause it to break under heavy loading. A hardwood like ash will take more abuse, but the extra weight can make it a handful for one person to handle.

Building a Better Boat Fender

A hole slightly larger than the diameter of the suspension or drop lines (say 9/16-inch hole for a half-inch line), is drilled through the larger dimension at either end of the board, about 6 inches from either end.

Next, round the ends of the plank and chamfer all edges. Your lines should be long enough to suspend the plank down to the waterline from whatever stanchions or cleats you plan to use.

After threading the lines through the holes, tie a figure-eight, stopper knot at the bottom of each line, and youre finished.

Because of the abuse fender boards are intended to take, painting or varnishing them is pretty much a waste of time. And, because you want a fender board to be as gentle as possible to your boat, complications like metal hanging straps or eye bolts are best avoided.

You can us your fender board with conventional round fenders, or you can purchase solid rubber cushions made specifically for attaching to 2×4 or 2×6 spars. Made by Taylor, they are available though most retail chandlers and online. In our experience they do not give the board quite as much standoff from the hull that a large round fender will, but because they are permanently attached to fender board, there is no risk that they will pop out of position, allowing the board to rest- and rub – against the topsides of your board.

Building a Better Boat Fender

The one embellishment you might wish to consider, if you have sufficient time and/or inclination, is a laminated fender board. This board is composed of three layers of 1x 3 fir, hickory, or ash. The layers are not laminated together, but slightly apart, separated by 1/8 strips of wood epoxied in at either end, creating a wooden fender that flexes like a leaf-spring. I saw one of these years ago, and, though I don’t imagine its much more effective than a length of solid 2 x 6, it certainly looked impressive and sowed a certain pride of ownership that a simpler board would lack.

Darrell Nicholson, editor of Practical Sailor, grew up boating on Miami’s Biscayne Bay on everything from prams to Morgan ketches. Two years out of Emory University, after a brief stint as a sportswriter, he set out from Miami aboard a 60-year-old wooden William Atkin ketch named Tosca. For 10 years, he and writer-photographer Theresa Gibbons explored the Caribbean, crossed the Pacific, and cruised Southeast Asia aboard Tosca, working along the way as journalists and documenting their adventures for various travel and sailing publications, including Cruising World, Sail, Sailing, Cruising Helmsman, and Sailing World. Upon his return to land life, Darrell became the associate editor, then senior editor at Cruising World magazine, where he worked for five years. Before taking on the editor’s position at Practical Sailor, Darrell was the editor of Offshore magazine, a boating-lifestyle magazine serving the New England area. Darrell has won multiple awards from Boating Writer’s International, including the Monk Farnham award for editorial excellence. He holds a U.S. Coast Guard 100-ton Master license and has worked as a harbor pilot and skippered a variety of commercial charter boats.


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