For my birthday this year I received a hammock. As one does, I tested it out using a couple of trees in the garden. The trees are a bit far apart for the hanging straps though, so I extended them with some old dyneema slings - so far so good.
It got me thinking that it might be good to take a couple of slings with me if I'm taking the hammock with me when travelling, but I'd like to save some weight and bulk. I was thinking about cutting the old sling open, and making a loop at each end thus more-or-less doubling the length, and halving the number I would need to carry. What would be the best easy to do this? Overhand knot? Water knot? Trying to home-brew some bar-tacks on my wife's sewing machine would be ideal, but I dont know how feasible this is. Safety is not a huge worry, as it will be a static load, slowly applied, with a maximum ground fall potential of about 0.3m to 0.5m. The sling itself is about 15 years old, so this would feel like a worthy retirement for it.