Today the customer has an infinite number of different types of sailcloth to choose from. I explain their strengths and weaknesses.
Before buying a new sailing wardrobe, it is imperative to set priorities. These are inevitable compromises between performance, cost and durability. And that is often done. not as easy as you might think at first glance, even with “easy” cruising sails.
The ability of a sail to maintain its intended shape influences the handling of the boat, which in turn is important for the comfort of the crew. As a result, all sailors worry about the amount of stretch the fabric will stretch as the wind increases or as the sail ages.
The three most important criteria to consider when buying a sail are:
If a sail stretches, the lowest point of the sail profile moves aft and the sail becomes more bulbous. This results in greater heeling and less height on the wind with greater windwardness at the rudder. The combination of these effects makes a boat more difficult to sail, less comfortable and slower on top of that. And a ship that is more difficult to steer is also more difficult to control, especially for inexperienced helmsmen and for the autopilot, who has to make more frequent and stronger corrections and thus uses more electricity. This also makes bad sails a safety issue.
Bulbous sails also have to be reefed earlier and more often, which in turn means more backbreaking work for the crew and also wears out the sails more: Because every kill and flutter (e.g. when arriving and leaving) damages the canvas for more than 50 miles with the correct trim.
Resistance to bending
This is the key to the longevity of every sail, the fibers of which are constantly bent or even kinked when folding, flapping, setting, recovering or reefing. The material that withstands this best, woven dacron, is unfortunately also the one that stretches the most.
Fibers that stretch the least, such as carbon fiber, on the other hand, are very sensitive to kinking. Aramids such as Technora and Spectra are a bit better in this case and are therefore often the cloth of choice for the laminate sails on larger racers / cruisers. Polyester, which is even better in this regard, is also used, but has the disadvantage of higher elongation and the permanent elongation of the fibers over time.
The resistance to bending of the fibers can be increased by adding a layer of polyester taffeta on both sides of the sail. This pays off particularly with sails that are used for fast cruising or long-distance regattas. That costs extra, but the dividend is paid back in the form of a significantly longer lifetime. A significant disadvantage here, however, is the higher weight, which in turn reduces performance because it is carried exactly where it hurts the most and also creates heeling: high up. As a rule of thumb, this means that for 10 kg more weight in the rig you need around 30 kg more ballast in the keel to compensate.
Once the only cloth available for upwind sails was woven Dacron (or polyester), but now there are significantly more options with laminate sails. These sails consist of several membrane layers that are glued together with the structural fibers in between, like a sausage in a sandwich. Such sails can. Either consist of one piece that can be gigantic, such as the 3DL sails from North with built-in fiber courses, or, more traditionally, they can also consist of sail panels that are sewn together, like a conventional dacron sail.
There are essentially two types of sails that consist of sail panels: The simplest are those with horizontal panels that run diagonally from the mast to the leech. So-called radial sails, in which the cut of the panels better match the load-bearing properties of the fabric, are on the rise.
Laminate sails, which consist of individual webs, are preferably produced in radial cut, because the cloth is designed in such a way that the fibers support this. In contrast, there are very few dacron cloths that are suitable for radial sail cut, because the fibers with the least stretch should run along the roll of cloth, not across, as is the case with a normal diagonal cut.
Another aspect of dacron sails is the density of the woven fibers, whereby the higher the figure, the less stretch. Then there is the resin, which gives the woven fibers more strength, but is shaken out of the fabric by the flutter over time. And then of course there is the question of price: Tightly woven dacron is expensive, so cheaper cloths are loosely woven, but soaked with more resin. Such. Sails look good at first, but they lose their shape relatively soon as they age.
This type of sail is usually the most expensive, but it has a number of advantages: The sailmaker has a free hand to position the load-bearing fibers precisely according to the load on the various parts of the sail. Sails for high offshore use can, for example, be reinforced with up to 40 percent more fibers than those that are primarily intended and made for cruises near the coast
The type of fibers used also depends on the purpose of the boat. Despite the rather low resistance to bending, carbon fiber is preferred by the really ambitious regatta sailors because it hardly stretches, while Technora / Spectra sails are often used on racers / cruisers, which are also coated with taffeta to ensure a longer service life.
If you want a sail that is suitable for several circumnavigations of the world, it is best to sail with a high quality and appropriately reinforced dacron cloth. The disadvantage: you will be traveling a large part of the way with a sail that does not retain much of its original shape because it stretches. Another cloth that could be considered is HydraNet radial, in which Dyneema fibers are woven. It is more expensive than woven dacron, but much more durable and holds its shape much better with advancing age.
In contrast, laminate sails keep their original shape until the end of their service life. This shelf life is shorter than that of a dacron sail and it has to be replaced when repairs become too expensive and uneconomical, even if the form itself is still usable. With proper treatment, cruising sails made of laminated cloth and coated with taffeta can last tens of thousands of miles.
Increase the service life
As mentioned above, killing and flapping reduce the durability of a sail. For cruising sailing, fully battened mainsails are recommended, which can hardly kill and therefore do their job for longer. It is a typical case where a higher investment initially lowers long-term costs because the sail doesn’t break and need to be replaced as quickly.
At this point a word about the reefing system. This should be functional and easy to use so that the sail itself does not flap for too long during the reefing process.
And another tip: when motor sailing, take the main close to avoid unnecessary killing, which inevitably causes damage to the sail.
Here I have an interesting book for you on this topic: