Out of Whole Cloth: Sailcloth 101
Sails: When upgrading your sail inventory, understanding the basics of cloths, laminates and construction will keep the wool from being pulled over your eyes.
Prior to the late 1980s and the introduction of North’s 3DL sails—so-called molded sails—sailmakers and cloth manufacturers were working on their own versions of what has become known as load-path or string sails, which is the other way of making a laminate fabric. Essentially, continuous fibers are glued down on a Mylar film in computer-generated paths engineered to handle the loads placed on the sail. Load-path construction eliminates the break in the fibers present in a sail fabricated from roll goods, where at each seam the fibers terminate and start again in the next panel.
CAD stands for computer-aided design, and CAM stands for computer-aided manufacturing; the shape of a load path sail is designed using the CAD elements of a CAD/CAM system. There are two stages to the sail-design process: aerodynamic shaping and engineering. After the sail is both designed and engineered, the basic sail skin, or Mylar, is crosscut; then each panel is glued to its mate using high-strength glue. With the film spread flat on a floor, the fibers are overlaid onto the Mylar sheet. Different sailmakers use proprietary techniques to unite the glue, the fiber, and the film as a working sail.
The one exception to this flat-floor method is North’s 3DL product, in its various versions. At North, the Mylar film is still cut and glued together, but it’s then laid onto the mold, a huge articulating machine that’s programmed to assume the same shape as the finished sail. The fibers and the rest of the components are laid onto the film on the mold using computer-controlled tooling. The whole sail is then pressurized and heated in much the same way as a hull or spar is produced in an autoclave.
These load-path sails thus combine making the sail with making the fabric, as both occur at the same time. Once the complete skin or membrane is cooked, it’s removed from the mold, and then the rest of the sail’s components—batten pockets, luff tape, numbers and lettering, headboard, and so on—are incorporated into a finished product.
Placing an Order
• Doyle Sailmakers: (978)-740-5950, http://www.doylesails.com
• Hood Sailmakers: (401) 849-9400, http://www.hood-sails.com
• Neil Pryde: (203) 375-2626, http://www.neilpryde.com
• North Sails: (203) 877-7621, http://www.northsails.com
• Quantum Sail-Design Group: (888) 773-4889, http://www.quantumsails.com
• UK Sailmakers: (718) 885-2028, http://www.uksailmakers.com
• Ullman Sails International: (949) 645-3114, http://www.ullmansails.com
Sailors have many things to consider when contemplating the purchase of new sails, especially laminated ones, but there are a few things to remember.
Generally speaking, in terms of durability, most sailmakers assume that three to five years is a reasonable life span for laminated sails, though many have clients who’ve gotten many more years of service. Incredibly, the threshold for many high-performance racing laminates is measured in hours.
For the most part, load-path sails feel smoother. In the assembly of the many panels of the sail made from roll goods—a practice in which the pieces are glued together by hand, which is an acquired, imperfect skill—the finished product can feel bumpy, and the seams often don’t lie flat when the sail is flying. These issues are minimized with load-path sails.
Pricewise, load-path sails are generally more expensive but retain their original shape longer. Their performance is better right out of the bag. And load-path sails are considerably lighter than laminate sails built with other methods.
We’ve introduced many terms and technologies here, but when you go to order sails, the list of items you need to communicate to your sailmaker are straightforward. Be clear about how you actually use your boat—how much, if ever, you race or head offshore; how often you sail in heavy weather; how long you intend on keeping the boat; the true-wind conditions of your most frequent cruising grounds. And of course, be crystal clear about your budget.
Sailmakers are, at heart, sailors themselves, and they love shooting the breeze about boats and sailing. Find one you trust. The ever-evolving technology in sailcloth and construction is fascinating, but at the end of the day, as with most transactions, buying sails is about forging relationships.
Joe Cooper (www.joecoopersailing.com) is a former sailmaker who’s sailed and raced boats ranging from dinghies to America’s Cup contenders. Currently a sailing coach and consultant, he lives in Middletown, Rhode Island.