Next, how much does stitching lengthen the life of the sails?

Not at all, but it could shorten it.


William R. Watt wrote:
shouldn't someone warn the professional sail lofts about this?


I think most of the good ones already know.


the only problem with both taping and sewing seams is the glue gums up the
needle on the sewing machine.

Why sew them if they're glued? Many sail lofts are now producing glued
seam sails... I have a ~200 Sq Ft spinnaker that I've flown in 20+ knot
winds, plenty strong.

Fresh Breezes- Doug King