Recently, on an overnight sail to relocate a boat to a different marina, we tore the headsail on our catalina 37. While we planned to replace the sail this winter, there are still many weeks of sailing yet this season. We also have not quite saved the money to replace it yet. This sail is a Kevlar sail that has seen many seasons, in fact we bought it well used 3 seasons ago for $300 it had been repaired several times before we bought it. Here's our attempt to repair it. It's held so far in a week of heavy use!
Step 1: lay the sail flat.
we had to come into the marina to do this repair, though we probably could have done it on board, this made it much easier.
make sure there are no wrinkles, when we match up the edges wrinkles can make the repair weak.