SailCare.com says they replace the "resin" that is on new sails and
they restitch whatever needs it. I want to know how to evaluate the
shape of a sail so I can decide the most effective way to restitch to
renew the shape. I agree, older material is probably not as strong as
newer but many sails arre very lightly used. Quite frankly, I simply
do not believe what sailmakers say about sails aging just by sitting on
a shelf. I also think that a considerable part of the stretch of an
older sail is in the stitching and not in th ematerial itself. Even
sail material that has stretched probably has not gone beyond the yield
point of the material so unless it is actually worn or degraded by UV,
I think that most of any loss of strength is in the stitching.
So, how does one evaluate the shape of a sail?