Tying monofilament fishing line presents real challenges due to its tendency to slip and snap under stress. Knots that work well with different materials and larger diameter ropes work poorly with nylon mono. Splicing braided line to monofilament or joining two lines of unequal diameter also requires special knots. Choose the right knot for the right purpose to gain maximum strength.
Terminal knots join monofilament lines directly to lures, swivels or flies. The knots allow very little play, fitting snugly against the tackle. The best knot for this application is the San Diego jam knot tied with six turns. Be sure that the turns don't overlap one another and that the knot is cinched down tight. The several turns provide grip friction and also have some cushioning effect.
Tying a splice in two lengths of line with different diameters can place uneven stress on the smaller line. The best knot for this job is the Yucatan splice, using six turns of a doubled smaller line. The smaller line doubled back on itself for a few inches evens out the build of the knot and gives it extra strength. To cinch the knot down tightly, moisten it before pulling it tight. Avoid overlaps and twists.
J knots do the best job of joining two equal diameter fishing lines. Pair the lines side by side and make an overhand knot with both strands, leaving several inches for convenience--trim them later. Pass the strands under the bottom loop, over the top loop and back down through the loop in an S-curve. Take a last turn under the bottom strands and pull the knot tight. The extra turns eliminate the sudden bend that causes monofilament to snap.
When tying onto lures that need free movement, the proper knot should have a small nonslip loop at the end. The best knot for this is the Rapala, a complicated series of twists and turns and wraps that stops the cinching action with an overhand knot. The result looks like a hangman's knot but has a different internal structure and does not tighten the loop under strain.
For saltwater fishing or for really big freshwater prey, baited hooks fare better with the snell knot. The snell attaches a leader to one or more hooks--a main line will later be tied to the leader. Pass the end of the leader through the front of the eye of the hook and hold it in place against the shank. From the eye downward, wrap the body of the leader around the shank eight times. Pass the leader through the eye again from the back, moisten the knot and pull tight. Correctly tied, this knot should lift the point of the hook upward. Use a second snell knot to tie a second hook in the same leader--pass the end of the leader through the front of the second hook's eye and repeat the knot.
- Snapper G at commons.wikimedia.org