When you are in the market for new sails, the number of available options might seem overwhelming! You will quickly be flooded with options like:
Dacron
Laminate
Taffeta Coating
Technora
Aramid
Tri Radial
Cross Cut
Carbon
ect.
To make these options make more sense, lets break it down into two camps:
Laminated Sails (Membrane)
Membrane sails are made by laminating various layers together to form the sail. These sails are not cut into pieces because the are made in one piece. The choices fall into what the layers are made of.
Dacron Sails (Cloth)
Cloth sails are made of polyester fibers that are woven into panels of cloth. These panels are then cut in various shapes: Cross Cut or Tri Radial
Dacron sails will last for many years, but they will only hold their proper shape for a few years, then the begin to stretch out and become baggy. The panels are the weak point, the larger the panel, the more profound the stretching will be.
Cross cut sails have large horizontal panels that will stretch rather quickly. The alternative is to have the panels cut into many smaller panels arranged in a way that they will help distribute the forces, prolonging its life of ideal sail shape.
This method is called Tri Radial cut sails. These sails are easy to distinguish from Cross Cut sails because Cross Cut look like rectangles stacked on top of each other. Tri Radial cut sails look like origami that has been unfolded.
It is not uncommon to see really old dacron sails (over 20 years old) because they hold together for a long time. They are rather resistant to chafe and any holes can be easily patched. Just be sure to examine your sails and replace them when they begin to sag in the wind like large burlap bags.
Another feature of dacron sails is they can be easily modified. If you decide you need an extra reef point, a sailmaker can easily sew one in for you without too much effort. This makes afterthought modifications possible, relieving some of the stress during the design process of the sail. If you are not sure that you will need a third reef, you can always add it later if you find that you did!
Dacron sails are also available in a selection of colors, the most common is white. Tanbark is a less common but still readily available color of dacron. Some specialty sailmakers offer dacron sails in a multitude of colors, but these locations are hard to find.
The alternative to Dacron is Laminated Sails. These sails are made by laminating various membranes and layers together to form a sail comprised of a single piece. There are no panels involved in the construction. Instead, fibers are run along the stressed load lines of the sail to evenly distribute the forces placed on them. These sails will never stretch until the day that they die, which is anywhere from 2 to 7 years (depending on how it is designed). While this might sound like a short lifespan, it is not!
Compare a laminated sail that lasts for 5 years to a dacron sails that lives for over 20 years. It might seem like a short life, but the dacron sail only held its shape for a few years and then began to stretch. The laminated sail held its shape perfectly for the whole 5 years, 2.5x the life of the dacron sail before it stretched!
Where dacron sails stretch out, laminated sails die in an explosive display. The laminates will separate in a process known as delamination which spells the end for the sail. A repair can be attempted, but it is the end for the sail.
Laminated sails also offer greatly reduced weight over dacron sails, which translates into reduced weight aloft. Racing sails offer the greatest weight savings, but also last the shortest amount of time. These are the sails that seem see through from a distance because they are purely milar and fibers. The fibers are what give these sails their colors.
Black fibers are from Carbon and Technora
Gold fibers are from Aramid
Tan fibers are from Vectran
White fibers are from Polyester
These see through racing sails will last between 2 to 3 years before the delaminate.
Cruising versions of laminated sails last longer by providing the sails with a Taffeta coating. This will extend the life of the sail to 5 to 7 years. Taffeta can be applied on one side for some protection or both sides for maximum protection. Taffeta gives the sail a white look, with the fibers shinning through. From a distance, these look like regular sails until you notice the fiber bands running through the sail.
The reason taffeta helps protect the laminated sails is because it is made of dacron! This coating helps protect the sail from chafe and wear, but it does add considerable weight to the sail. If you decide to go with a laminated sail, I strongly recommend the taffeta coating, it only costs a little extra but it greatly increases the longevity of the sail.
If you are planning a long offshore voyage with laminate sails, I would strongly urge you to carry a spare set of sails in the event that one of the sails dies while offshore.
The choice ultimately comes down to what suits your needs best? If you are racing, then a stripped down laminated sail is right up your alley. If you are doing coastal cruising or short offshore jaunts, laminated sails with taffeta coating will provide a wonderful service life for you. If you plan on sailing far offshore, bullet proof dacron sails might be your best choice. They won't hold their shape forever, but you will always have a sail to get you home!