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Mainsail Details

AirForce Sails Product Manager Brian Hancock continues his Sail Tech series, offering some strong pointers on the details you need in a proper mainsail. (Review Part Four.)

Slicing effortlessly to weather is a byproduct of a well-built, well-trimmed mainsail working in unison with the hull, keel, and headsail.
There is nothing quite like sailing to windward on a smooth sea. The bow knifes through clear water, rising with each swell, and dropping gently into the troughs. From your vantage point at the wheel, you feel the helm tug with each puff of wind, and with fingertip control you guide the boat toward the distant horizon. All of this pure magic is made possible by a well-built, well-trimmed mainsail working with your keel to provide lift, and just the right headsail powering you forward.

In the first four articles of this series we looked at the various fibers that are used to make sailcloth, how they are incorporated into different fabrics, and how the fabrics are used in different panel layouts to take full advantage of their best qualities. We even described the best ways to assess how much life is left in your old sailsF and provided pointers for deciding when it's time to replace them. Now it's time to take a closer look into the details and features that go into making each sail. It's those details that collectively provide safe, fun, satisfying performance while sailing, not only on sunny days when the wind is just right, but on those not-so-great days when the weather pipes up and turns nasty. A well built sail is the sum of its parts, and it's those parts that we will concentrate on in this segment.

Having accessible, easy-to-cleat leech and foot lines can help you achieve the proper sail trim underway.
Let's look at a mainsail, part by part, to determine what features are best for you, starting with the number of reefs. If you live in the northeastern US, like I do, and only sail in the summer, then more than likely you will only have occasional need for a single reef. There is almost no point adding a second reef as it only adds weight to your sail, making it harder to set and trim, and of course it adds to the price. On the other hand, if you are planning on heading for distant shores and encountering the vagaries of the wind gods, then don't leave home without a second, and in some cases, a third reef. You will need them. Whatever the case, make sure that the first reef counts. Have your sailmaker make it deep enough so that when you reduce sail, you actually feel the difference.

With laminated sails, be sure that there is a reinforcement strip running across the sail at each reef point to take the outhaul load. Because of the radial panel layout, the threadline across the sail is on the bias and vulnerable to stretching and distortion. Discuss your sailing plans with your sailmaker to be sure that the number and size of reefs are suitable for the type of sailing you plan to do, and that they compliment your headsail configuration. Finally, and most importantly, ask your sailmaker to add rings sewn to webbing, often called "floppys", (and if you have a larger boat, webbing handholds) to the luff end of the reefs. These items will make it easier to secure the luff, and a handhold will give you something to grab onto when reefing.

Proper reinforcing, like this webbing strap in the clew, is another detail to look for in good sail construction.
Next comes the question of battens. Your choices are simple—opt for all full-length battens, a mixture of full-length and extended battens, or the more conventional design of all short-length battens. I would exclude the last option from any cruising mainsail. Full-length battens add to the life of a sail and definitely help with sail handling. My recommendation is for a main with two—or for larger sails—three full-length battens up high, and two extended (longer than normal) battens down low. The full-length battens support the roach, and when used with lazy jacks (or any retaining system), can really make things easier when raising or dropping the sail. Omitting the battens throughout the reef area eliminates any chance of them hanging up while reefing, and also allows you to feed shape into the sail when you ease the outhaul. Having full-length battens down low limits your ability to adjust the sail because the stiffness of the battens ends up dictating the shape.

Be sure that the outboard and inboard ends of the batten pockets are reinforced, and that the inboard ends of the extended battens have reinforcing patches. These areas are vulnerable to chafe and distortion and need to be protected. When it comes to batten materials, there's quite a bit of choice for the performance cruiser. I have always been an advocate of simple and strong. Fancy battens often have problems and I speak from experience—I have carbon-fiber battens in my own boat, and while I appreciate the weight savings and stiffness, these are expensive to replace when they break. Tapered epoxy, E-glass battens are all you really need. The tapering helps with sail shape and the E-glass is rugged enough to take most normal wear and tear.

Webbing handles and floppy rings like those shown here can come in really handy when you need to tuck in a quick reef.
One of the great advances in sail handling over the last few years has been in the area of luff-attachment hardware. The engineering of modern sail designs is intended to handle the compression loads exerted by full-length battens, and these products make raising and lowering the sail easier than ever before. There are many choices out there, so do your homework and find a system that fits your budget and your needs.

Now comes the question of opting for a loose foot or a slide or bolt-rope-attachment. Many older designs still offer a track along the boom, calling for slides to be built into the foot of the mainsail. Unless you are hoping to collect rainwater to fill your tanks while sailing offshore, this old way of doing things should be discarded in favor of a loose-footed mainsail. The loose-footed arrangment is cleaner, simpler, friction free, and it allows for more adjustment to the sail shape. You simply have the sail attached at the tack in a conventional manner, and attach the clew to the outhaul car. The foot round in the sail should drape below the boom, which adds area. For reef lines, you can use your old system, or simply tie the line around the boom at the appropriate location. It's a small change from the old way of doing things, but I am sure that you will find it a big help.

Look closely at the details in your new sail. Does it have two rows of stitching, or better yet, three, between the panels?
That takes care of the main features, but often it's the less obvious areas of a sail that you need to pay attention to. Remember, the devil is in the details. If you are going offshore, make sure that your sail has double tapes around the edges. This is an area where some sailmakers skimp and you end up paying the price down the road. On the leech between reefs there should be a large second ply of fabric to handle the load and the abuse this area will receive when you reef. Two rows of stitching in all areas of the sail are usually adequate for boats up to 35 feet, but if you are heading offshore or have a bigger boat, then insist on three rows throughout. The same applies to webbing the corner rings or cringles. If you are heading offshore or have a bigger boat, make sure that your corner rings are webbed for extra strength. At AirForce Sails we use Spectra webbing, and sew it down with a special Gore-Tex thread that withstands chafe and never rots in the sun. Lastly, an overhead leech line is necessary on boats where you can't reach the boom. The line runs over a block at the head of the sail and down the luff to a cleat where it is easy to reach and adjust. Double, overhead leech lines are nice on bigger boats, where one acts as a back-up and having two allows you to make adjustments from the windward side—a safety issue as well as a convenience.

As I pointed out before, a great sail is really the sum of its parts. Choose your fabric carefully, know your sailing plans so that you can decide what features you need, pay attention to the details, and make sure that your sailmaker has all the information he or she needs to make you the best possible product. Remember, this is a custom item, and like a great suit, the detail in the tailoring will pay dividends for years to come.

Look for the next of Brian Hancock's Sail Tech articles in early July.


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