I believe when you are fly fishing the clear cold waters here in the West, it pays big dividends to use fluorocarbon leader material. Its advantages: Virtually invisible underwater, it sinks quickly and it doesn’t reflect light on the water surface, fish can’t see it and your catch rates go up over monofilament. Yes, it can be more expensive, but to improve a day’s fishing and change an average day into a great day, it’s worth it to me. I was first introduced to fluorocarbon in the mid 90’s when the import fishing tackle company where I worked, received samples from one of our contacts in Japan. I tried some of the 3 lb test and 4.5 lb test and really liked the heavier test and how well it fished.
Depending on the brand, you may have to try several different knots when making up a knotted taper leaders using fluorocarbon or when you are tying a fluorocarbon leader tippet to a monofilament leader. A great knot to connect the leader sections together and, perhaps the most popular is the blood knot. It is fairly easy to tie and it doesn’t waste a lot of material.
When you need to join two vastly different sizes of leader material together, for example l5 lb to 6 lb, use the improved blood knot: Double over the smaller size of leader material and then tie the blood knot with 4 wraps of the doubled 6lb on one side and 3 wraps of the 15lb on the other side. A very simple knot when tying different sizes of material together and one that has 100% knot strength with fluorocarbon, is the triple surgeon’s knot, it’s not pretty but it really works. I also like to use the triple surgeon’s knot during low light conditions to retie fine fluorocarbon leader tippets.
Use the Uni knot to tie the fluorocarbon tippet of your fly leader to the fly. It also has 100% knot strength with fluorocarbon. To tie the fly leader to a fly line use a nail knot. To make a loop-to-loop connection to change leaders: Cut the first butt section of the fly leader 8 inches below the nail knot and tie perfection loop knots to the cut ends and loop them back together. When tying all types of fishing knots, use saliva to make them slick, and then draw the knot up tight but slowly to reduce friction.