If you have two leashes that are broke- you might be able to make one good one out of the two bad... I know it's a bummer... No one really likes to buy new leashes... But just get a new one. The key to keeping a leash for years is: 1. Don't rely on your leash. Hold onto your board- kick out when you can. 2. Rinse of your leash after each use. Seriously keeps the Velcro , fabric in better conduction and less corrosion on the swivel which is usually just copper- not too strong
Cep, as Towlie insinuated, temp control. A steady flame to both sides until it is soft and gooey (not dripping)then immediately press the two sides together and hold. I was not a believer until I tried it myself. My bro in HI did it first and swore by it and I surfed with him in solid surf and it did not come apart....then some months later I was in the same boat and did it and it worked. These days I would go buy I new leash but $25 back then was a night out