Your Sailmaker designed the ideal sail shape for your boat, the type of sailing you enjoy and your local conditions. The design was based on using a cloth that best suited your application when new. Over time your cloth has deteriorated, reducing its ability to resist the stretching forces on your sail and so loosing the shape your Sailmaker intended. The effects of this can seriously effect your sailing enjoyment that is why it is important you specify a quality cloth.

• Your mainsail will become more full causing more heeling, less speed and earlier reefing.
  • Your headsail will also become more full reducing your pointing ability so you have to tack more often.
  • The camber (the deepest part of your sail) will move aft causing more heeling force and drag, and less forward drive.
  • The leeches of your sail will fall away reducing your pointing ability and the gust response of your rig with your sails stretching and releasing the extra wind power instead of harnessing it to accelerate your boat.

Racing sailors are very aware of these problems as speed difference between old and new sails is easy to spot. Cruising sailors are also becoming more aware of the effects of poor sails. Stretching sails = more tacking, more reefing, more heeling, longer to get to a destination = less enjoyment.

Why does sailcloth deteriorate?
• UV light seriously reduces the strength of the fibres used in sailcloth, in extreme cases up to 50% in 3 months.
• All materials loose strength when they are bent back and forth or ‘flexed’. When a sail flogs this flexing action damages the fibres.
• Static tensile loads such as leech, outhaul and halyard tension all stretch the fibres. Over time they loose the ability to recover and the sail will then never return to the design shape.
• All woven sailcloth has a hard resin finish that protects the fibre from UV, prevents water absorbsion and locks the weave together. This finish is relatively brittle and breaks down with flogging and flexing so causing the sail to feel soft and soggy and loosing the ability to resist diagonal bias loads.

When will I need a new sail?
When you notice that the performance of your boat is less than you are happy with it is time to change but at what point this is depends on the type of sailing you enjoy. Some racing sailors using very light laminate sails notice a reduction in performance after just one regatta. Cruising sailors may not notice a performance drop for a number of years particularly if the sail is made from a fabric such as CL cruising laminate.

This article was compiled from http://www.sailcloth.com/