I will be replacing some well worn leaders on my fly reels soon. my fly line is a solid coreand so I was going to use a duncan loop to attach my leader. My leaders have a loop at the end. My question is, should I just cut off the loop and use the duncan method? I can’t find anything on how to tie the leader with a pre-made loop.
The “duncan”? Isn’t that like a uni- knot? Why don’t you just use some mono and nail knot it to the line, then form a perfection loop in the front end, and “handshake” the leader to the perfection loop end of the line? Works slick as snot!!
What Betty said…probably the most commonly used way…
You might consider using the Castwell knot…see the “Knot” section under “Features”…many of us like that.
use the search function on this site. there alot of recent information regarding knots, loops, fly lines, leaders etc
duncan loop is for tying on flies. could be used but i wouldnt. tie on a 12-15 inch long butt section to the fly line with a nail knot. put a loop in the leader end with a perfection loop and a loop in the butt section of the leader and loop to loop them together.
What she said.
I use a short (really short, like < 3") length of Amnesia running line with a perfection loop. The Amnesia is stiff enough to act more like an extension of the flyline for a better transfer of power and reduced hinge effect. Also the bright red acts as a sort of built in strike indicator when nymphing, but is well away from the fly so it doesnt mess up any dry presentations.
x4 I keep a spool of 40lb. Maxima on hand at all times. Attach a pc. to the line using a nail not. (sometimes, I add a drop of Zap-A-Gap, but I’ve never had one come undone without it) I then, to reiterate, form a small perfection loop as close to the fly line as possible. Done! Why 40lb? You don’t want this interface to be soft, or it will create a “hinge” effect between the leader and line. When I’m half-asleep, making one of these connections at 2 in the morning before a fishing trip, it can take 1-2 attempts to get the nail not looking pretty.
For the most part I’m a loop to looper, i.e., like Betty was explaining … attach a short piece of mono to the end of the fly line, tie a loop in the mono’s other end and all is set to attach a looped leader. And there are different methods/knots used for attaching the mono to the fly line. For me, I’ve kinda experimented around and found out what fits my kind of fly fishing - a different method for light, medium, heavy … or let me 'splaine a little -
Light: for pan fish, trout, smaller bass ~ using either the 4 or 5wt rod, here I really like using the Eagle Claw “leader links”. Been using them for years and you simply tie a simple knot it both the line and the short length of mono which is then looped:
http://www.stevesfishingsupplies.com/Category/fly_fishing/Eagle_Claw.html
Medium: for larger fish I use a 7wt rod and here I liked the nail knot/short mono piece looped. But the Castwell knot works here real well, too.
Heavy: for the big fish I go after, red drum, salmon, steel head; and I use a 9wt rod. Here I like to loop the end of the fly line using a winding/glue method. When it’s time to attach a leader, simply loop the leader and make the loop to loop connection.
Dale
There is a knot in the knot section of this website called 'The Castwell’s Knot". The animation shows a “looped leader” end tied to a “flyline”. It looks very simple. Since my leader already has a pre-made looped end, this looks perfect. But does anybody know anymore about this method?
Here is a link to a web site with instructions for making a welded loop in the end of your fly line, just like the factory loop…
http://www.fishandfly.com/articles/20090320_1
The loop to loop connection it sometimes refered to as the hand shake knot…
http://www.smokyonthefly.com/knot6.html
http://killroys.com/knots/looploop.htm
I like to do as Betty suggested, nail knot a small piece of heavy mono to the flyline and add a perfection loop.
http://www.smokyonthefly.com/knot2.html
http://killroys.com/knots/perfecti.htm
I use the Castwell knot on most of my lines. Very easy to tie, very little waste and it can be undone and retied. Some folks don’t trust’em cause they’re so simple. I’ve never had one fail…yet. Jim
Baybum,
If you do a search here for the Castwell Knot you will come up with LOTS of information about this knot.
What I know about it that matters is this:
It’s simple. It’s strong. It does not ‘come undone’ (some folks have expressed concerns about that). It uses only a very small section of fly line to tie it. It slides through guides as well as any of the other methods that use knots.
Is it the ‘best’ way? Don’t think there is one. All the methods that folks will suggest here work just fine. Doubt that any one of them is ‘superior’ to any other.
If my floating fly line comes with a factory loop, I use that. If it doesn’t, I use the Castwell knot.
Buddy
Which raises another question … promise Baybum, I won’t hold your thread hostage!!
If you are going to use the Castwell knot, and I must confess, I never have, do you use the regular coated fly line as it comes off the reel, to loop through the shorb loop on the leader? 
<OK … I hear the hissing and the oooooooo’s. >
OK, Baybum … only once more?
I got the line tied through the shorb loop, snugged down all well and good, but how the heck do you get it untied to change the leader? That puppy is TIGHT!
Gawd! The leader/loop to loop/perfection loop/mono/line is so much easier!!
I like the connection where you use a needle to pull the butt end of a piece of stiff leader into the fly line, after dressing with zap-a-gap. Then a perfectin loop in the leader to make the hand-shake connection. It makes for a very smooth transition into the guides, and I’ve been using it for years and never had one fail.