This classic sailor’s knot is ideal for connecting two ropes, especially when the rope sizes differ significantly. The sheet bend is a very secure knot that also unties easily, making it handy around camp.
Form a loop in the end of the thicker rope. Pass the thinner rope through the loop and behind the doubled section of the thicker rope.
Tuck the thinner rope under itself at the loop, then overtop the thicker rope.
Tighten by pulling all four ends.