Fly Fishing Knots
Thanks to FlyAnglersOnLine.com for the use of the animated knots.
The first thing to understand is there is no single perfect knot for every situation. Each knot has its benefits and draw backs. One may be stronger, but may be more difficult to tie. Not all knots work with line of differing thicknesses. Remember to always lubricate the line before tightening a knot, using water or saliva. And finally, trim the loose ends close to the knot to prevent the pick up of vegetation by the tag ends.
Research the knots you need and practice to get comfortable with them. This will pay dividends when fishing. On a rocking boat or waist deep in water with fish biting all around you is not the time to learn a new knot.
You need a knot to connect the Backing to the Reel (Arbor Knot); the Backing to the Fly Line (Nail Knot); a terminal loop connection for Loop to Loop Fly line to Leader or Loop to Fly (Surgeon's Loop); a knot to connect line to line (including lines of differing thicknesses), such as when building leaders or replacing tippet material (Surgeon's Knot); and a terminal tackle connection, such as tippet to a fly. (Eugene Bend Knot)
Lefty Kreh recommends against the Improved Cinch knot. "I had used it for years, since it was the first knot I learned. If you are comfortable with the Improved Cinch knot, consider doubling your line and use the doubled end to tie the improved Cinch. This increases its strength to over 95%. Saltwater fish are typically stronger than freshwater fish and I noticed that I had more knot failures than I had experiences in the past. I suggest the Eugene Bend Knot, Trilene Knot or Palomar Knot to connect directly to terminal tackle. I use a Surgeons Loop to connect to flies that need a loose connection to increase the flies action."
"To form a loop in the end of my fly line, I prefer to use a heavy mono or Fluorocarbon and tie a nail knot or two around the fly line to form a loop. I then wrap the nail knots with Fly tying Mono or thread and coat this with UV Knot Sense. The chinese finger puzzle type loop to loop connectors may be okay for small to moderate trout, but I have heard too many stories about them failing on large Trout and in Saltwater applications. "
UV Knot Sense is a compound that protects knots and keeps them from slipping, provided they are tied and tightened properly. It comes in a small tube and is activated by UV light, so apply it in the shade and them expose the knot to the sunlight to get a quick cure of the compound. If you attempt to apply UV Knot Sense in direct sunlight, it will literally cure as it comes out of the tube and form a thick gel.
Backing Knot to Reel
Shown above is an overhand knot around the backing, with an overhand knot in the end of the backing. This first overhand knot slips to allow the Backing to grip the reel and allow purchase to pull line in. The second overhand knot prevents the first from coming undone. This knot gets tighter the harder you pull on it.
Albright Knot
The Albright Knot is used to join two lines of differing thicknesses, such as building Leaders.
Albright Knot rated at 95 to 100% of line strength
- Knot illustration courtesy of ProKnot.com
Blood Knot rated at 80 to 85% of line strength
The Blood Knot is used to join two lines of approximately the same diameter. (within 1X of each other)
Eugene Bend Knot at rated close to 100% of line strength
Lefty Kreh recommends the “Eugene Bend Knot” to connect the leader to the fly. When done correctly, this knot gives off a “Click or Pop”, as the knot becomes fully seating during tightening and provides 100% of the line strength. To tighten the Eugene Bend Knot: Pull the tag end of the line away from the hook until the knot is snug, but not completely tight. The knot will slide up the line away from the hook, it is okay. To set the knot: Lubricate with water or siliva and pull the standing end of the line until the knot slides down the line to the fly and seats. This is when you should hear the click or pop, signaling the knot is fully seated. The Tag end will form a "V" in reference to the standing line. Clip the tag end short so it will not collect moss and other items. This knot worked well on tippets up to 12-15 pounds. At that point it is difficult to fully seat the knot using hard mono lines.
Palomar Knot
Knots that hold the hook and have the line pass through the eye twice, such as the Trilene and Palomar knots are stronger knots, providing almost full line strength. The Palomar Knot is also useful for tying terminal tackle to Kevlar lines, such as Power Pro.
Palomar Knot rated at 85 to 90% of line strength
Trilene Knot rated at 85 to 95% of line strength
Another Knot Lefty Kreh recommendations for connecting the fly to the leader is the Trilene Knot. “This is one of the strongest and easiest knots to attach your tippet to fly. Since the tippet must pass through the hook twice, it does not work well with small hook eyes.” This is rarely an issue in saltwater fishing. Make sure you close it tightly.
- Knot illustration courtesy of ProKnot.com
Perfection Loop
The Perfection Loop is an easy-to-tie terminal loop to create a loop-to-loop connection or allow the fly to maintain full action in the water.
Perfection Loop is rated at near 100% of line strength.
- Knot illustration courtesy of ProKnot.com
Nail Knot
The Nail Knot is used to connect Backing to Fly Line and the Leader Fly Line.
Nail knot is rated near 100% line strength.
- Knot illustration courtesy of ProKnot.com
Surgeons Loop
The Surgeon's Loop is used to create a Loop-to-Loop connection or create a Loop connection that will allow the fly to maintain its action in the water.
Surgeon's loop is rated near 100% line strength.
- Knot illustration courtesy of ProKnot.com
Surgeons Knot Rated at 90-95% of line strength. - Knot illustration courtesy of ProKnot.com
The Surgeon's Knot is easy to tie and is used to connect two lines together. Also good for connecting a heavier line to a lighter one, such as building leaders.
- Knot illustration courtesy of ProKnot.com 
Uni Knot
The Uni Knot is used to connect the Leader to the Fly.
Uni Knot is rated at 80-85% of line strength, however a Doubled Uni Knot is rated at near 100% of line strength.
- Knot illustration courtesy of ProKnot.com
Improved Cinch Knot
Improved Cinch Knot is often used to connect leader to Flies, probably because it is easy to tie. Lefty Kreh has researched knots and determined the Improved Cinch Knot to be one of the weakest Knots used to tie on flies. He recommends against selecting this as you choice for terminal tackle.
Improved Cinch Knot is rated at 85-90% of line strength, however by Doubling the Improved Cinch Knot, its rating improved to over 95% of line strength.
Credit to "Practical Fishing Knots" by Mark Sosin and Lefty Kreh
Lyon & Burford, Publishers
Step 1(see above) - Measure about four feet of line (you can use more or less line depending on the size of the loop desired) and double the tag end back against the standing part. Grasp the standing part and the tag end between the thumb and forefinger of your of your left hand. Slip your right hand through the loop and against the closed end. Rotate your right hand in a clockwise direction twenty times, putting twenty or more twists in the line while holding the line in your left hand securely.
Step 3 - The key to this step lies in constantly maintaining a 90-degree angle between the standing part and the tag end. With the twist jammed together (step 2), move your hands to the right (at the same time). That brings the standing part directly in line with the twists and the tag end at a right angle. Pull toward you on the standing part and ease your right hand away from you slightly until the tag end jumps the first twist. As you pull on the standing part, you have to feed the tag end gradually toward the twists. Place the forefinger of your right hand against one leg of the loop and pull toward you to continue the spiral wraps.
Step 4 - Don't relax the pressure on the standing part for an instant. Slide your left hand down the standing part until you can reach the final spiral wrap with the thumb and forefinger. The loop remains over your knee or foot. As you hold the spiral wraps between the and forefinger of the left hand, use your right hand to pass the tag end around the standing leg of the loop and then back through the small loop you just created. Pull the tag end toward you until the small loop closes and then work it back toward the spiral wraps until it locks Now you can let go with both hands take the main loop off your knee or foot.
Step 5 - Hold the two legs of the loop together. About two inches to the right of the twists and spiral wraps, pass the tag end over both legs of the loop and back through the small loop created by the belly in the tag end. Do the same four more times, working from right to left and toward the twists.
Step 6 - Pull the tag end toward you with your left hand as you careful work the new spirals back toward the twist. It's a process of spreading, and so forth until this lock knot seats tightly against the bimini twists. On lines heavier than twelve pound test, grip the tag end with a pair of pliers after hand tightening to add the needed presure to seat the knot.
Step 7 - Trim the tag end close to the knot and the result should look like this.
