A moving unweighted rope being pulled through an in-situ nylon sling is not going to lead to much friction wear on said sling, will it?
Using a sling of unknown history is done all the time in canyons, and if the prior sling looks new, but you do not know its history, just rotate the previous rope-rub area of the sling a bit around the tree that it is on. If the sling appears old or faded by UV, then replace it - or use it as well as using your own sling. I once counted 14 different slings around a log in Kelvinator canyon to rap off - I didn't put any there, and did not know the history of any of them. I used all of them, as it also added to less sharp angle of the rope bend.
A bail biner won't stay - unless it is glued. Who carries glue all the time?
The surface rust on that bail biner? How deep does it go?
These things said, a bail-biner/maillon will keep its size uniformly, whereas I have seen slings that were barely long enough to go around a tree, twist into a small hole, and pinch the rope tightly. |