Yes and no. I fact I talked at some length with "that guy," now retired, from North
Sails.
If the cloth is still good, get out the stitching palm and re-sew through the existing holes. Very easy and the correct way to do the job. I enjoy hand sewing. It's relaxing and a vital part of seamanship.
If the cloth is too far gone to hold stitches, yes, glue can
work. It is often the very best answer (other than a new sail). However, there are challenges:
- The normal seam overlap is not really enough bond area.
- The sun will loosen the patch in ~ 150 days of exposure. The UV basically attacks the bond right through the cloth. North did not test that.
- You have to hold the seam flat and still for a day or more while it cures. Not easy.
It would NOT be my first choice. Below is a long-term review of
adhesive repair methods. I've used several polyurethanes and Dr. Sails with good success (but I sew whenever applicable).
https://www.practical-sailor.com/issues/44_6/features/Simple-Sail-Repair_12428-1.htm
Dr. Sails is very good for this, solving the above problems (including UV), but you'd have to order it and it is more
money. Dr. Sails is probably the BEST solution for laminate sails, since they don't like stitching, particularly not used.
Dr. Sails Rules!
Sail Delmarva: Dr. Sails