Because North Sails builds more sails than any other sailmaker in the world, our design, service and sales staff sees ample anecdotal evidence of how sails age over time. North combines these observed effects from sun exposure, moisture and mildew with additional controlled research to continually improve our understanding of sail degradation.
Working with the world’s leading UV research laboratory in Florida, North conducts ongoing long-term tests covering our entire product line. This lab specializes in controlled exposure of materials to natural sunlight. An often-used alternative method is to perform tests using artificial simulation of the sun’s UV rays. While this produces test results much more rapidly, our experience indicates results have not been consistent with damage we have observed in actual sails. Outdoor testing in natural sunlight takes more time, but we believe the reliability of the data is worth the wait.
To date, over 750 samples of both North and competitors sailcloth have been tested, representing the most ambitious UV testing program in sailmaking. The degraded fabrics are analyzed after 500, 1000, 1500 and 2000 hours of sun exposure. Half of the fabric samples are tested for ultimate tensile strength yield and half are run through North’s FlexCycle test to simulate flogging fatigue, and then tested for tensile strength.
Included in North’s UV research are sail samples collected from Open 60’ monohulls that have raced around the world. Samples have also been extracted from similar areas of competitors sails, including areas that have been subjected to compression, flex and some from clear areas of the sails. Since these boats sail the same course in similar conditions, the results provide a reliable comparison of sail degradation over a known distance and time.