By: Andy Camarda
A note on RF mains
Furling get ignored due to some of the limitations of their shape. Because the sails have to wrap around a straight spindle and are limited by the interior volume of the mast, the designers must balance the ideal shape with proper furling. Most sailors assume because of this compromise that furling mainsails do not need higher end materials. As the depth of the sail increases and the sail becomes more 3D, a stretchy material for the furling main may still wrap around a 2D spindle and fit into the mast. As these sails age, that big belly causes them to furl poorly or not at all, meaning the sail may need to be replaced well before it has structural decay due to the shape deforming.
Ways to avoid shape deformation
Preventing a sail from aging starts before the sail is even built. Buying the right material for the job will prevent the sail from losing its shape prematurely. A good sailmaker will consider what the sail and boat are being used for and use a material that will not only structurally handle the demands (not falling apart) but also hold its shape for the life of the sail. In a day and age where sail materials and construction have improved and sails are lasting longer, it becomes more important to get a material that is going to hold its shape for the expected life of the sail. This becomes doubly important for sails that will be replaced based mainly on their shape and performance like racing headsails.
You can think of sails as having a certain number of hours on them before the shape moves outside of the acceptable window. Using a sail in its prescribed wind range causes that clock to move at a slow predictable rate. Most sails will not instantly blow out if sailed beyond the designed wind range, but the clock on its shape will start ticking faster if used in heavier breeze than expected. Short stints slightly over the recommended wind range won’t destroy a sail but will age it faster. Long stints well above the wind range will age the sail faster and will greatly decrease its life.
Make sure the reefs are correctly reinforced
Reefing and furling put loads on the sails in different directions than normal sailing will. If the sail is planned to be reefed either a roller furling or using traditional slab reefing, talk to your sailmaker to get it properly reinforced. Certain materials and design elements will handle reefing loads better. Membrane sails can have additional fibers run to create essentially an additional foot at each of the reefs. Whereas some woven and triradial materials do not have fibers running in the correct orientation for reefing and either need additional material ran or should be avoided for sails that will be reefed often.
Properly using the leech and foot lines will extend the life of the sail
Leech and foot lines are on the sail to prevent fluttering along the edges, particularly in heavy air. As sails age, the leech will start to stretch and flutter. If the fluttering is left unchecked, it will start to stretch the leech, not only creating issues with return and drag, but will also make the fluttering worse and continue to compound. Each time you go sailing, start with the leech line eased and add tension until it just stops fluttering. In light air or with a new sail, leech line might not be required at all. Foot lines are used the same way, but generally require less attention as they flap less.
Why does shape matter for cruising sails?
Reading this article, one may think this is primarily aimed at racing sailors, but cruising sails also require a proper shape to work correctly. Generally, the tolerances are looser for cruising sails, as losing a small amount of speed or point does not greatly concern most cruisers. Where it does become more important is when we look at the control of the boat, particularly in heavy air. A blown out sail will heel the boat over considerably more than one with proper shape. This will not only make sailing slower but more uncomfortable.
Using blown out sails for light air?
When I was a kid, we would always use my dad’s old sails when the wind went light because I was told they were older and deeper. He wasn’t the only one that had that opinion. Today, however, things have changed and we have learned more about how sails work. While sails do get deeper as they get older and create more power, they also see the draft move aft creating a fine entry and a narrow groove which can make driving more difficult and the boat slower in unstable light breezes. Additionally, the higher drag from the greater leech return also slows the boat down with the additional drag. These most sails come from the sailmaker with the ideal shape for their wind range making them faster out of the box, and not getting faster as they age.
