Monday, 20 August 2012

Bound to Fail - The 'Knotless Knot' Exposed

I've used the knotless knot only during the course of this year's fishing. Before, I 'd always tied my hair separately and then tied hook to line with a palomar knot, a knot that has never once failed me. I decided to try it out because of its convenience, it being hair and knot in one swift, neat tie up. I have banked plenty of fish with it, but have lost quite a few too, and not necessarily the biggest or strongest.

There was a tench that mysteriously broke the line at the knot, a weeded tench that suddenly wasn't there but had taken the hook with it, a large Thames fish that I thought must have been a pike that had taken a very big piece of meat intended for chub or barbel, the line failing so easily, and a series of inexplicable breakages whilst pulling against snags.

None of these breakages occurred under what I would think a hard pull, in fact the most remarkable thing about all of them was the lack of strength required to accomplish them. I put them all down to experience, and hadn't begun to link them all up to a single identifiable cause, even though they all showed the self-same sign of failure in the form of a short curly tail.

Then on Saturday, I lost two fish in quick succession, one of them a real powerhouse that might well have been a personal best barbel or carp, and suddenly, the links became apparent. There was something wrong with the knot, and I was sure of it.

I can be pretty slapdash at times, relying on tried and trusted tackle and rigs, and not, it has to be said, taking great pains over them. However, when I have a mind to, I am the most pernickety, analytical and scientific of anglers. I hate to be broken up, but hate even more not knowing exactly and precisely why, so I set out to discover the true cause of the disastrous weakness of this well used and trusted knot.

It didn't take long...

Trawling through a few forums I found plenty of references to the self-same problem I'd encountered. It seemed that it was nothing to do with my own bad luck, bad knot tying, bad tackle management, wasn't due to dinks, nicks, or abrasions in the line, but was to do with the mechanics of the knot itself and the way the knot reacted when under stress and strain.

'I had similar problems with mono and the knotless knot. I would land a fish then it would fail on the next fish.'

'Lost a fish due to a breakage on the hook-link. The line had parted and left a 5mm curly tail which indicated to me that the line had broken along the hook shank. This hooklink was fine last week and I landed a good fish which put alot of pressure on the line with no problems.'

'It's failed me many times. Most memorably when I lost four carp in under an hour on a really headbanging water in Sussex. I must stress this knotless knot failure is only with mono of some sort (nylon, copolymer or fluorocarbon) and not with braid, which I have every confidence in.'

'I was quite happy with the knotless knot until very recently when I had several breaks right next to the hook when fish made it into snags. The line was 10lb Berkeley Fluoro, the snags only lillies and the same line had happilly handled a far bigger fish only a few days before.'

'Once I had gone to a stronger rod all my hooklinks broke right next to the Knotless Knot, with a slight curve at the broken end. '

The forum threads went on to mull the problem over and came up with all kinds of reasons why such disasters might have happened with the most suggested culprit being the way the line exits the knot at the eye. 

However, I soon found out that the real reason why the knotless knot fails is nothing whatsoever to do with the eye of the hook, or the angle at which the line passes over it, as many believe. The real cause is the fact that the knot is really not a knot at all, but more of a lashing. Because the knot has no means of locking itself, despite your best efforts to properly bed it, every time the line is tensioned or relaxed, the knot itself tightens and loosens. With the aid of reading glasses I could see the knot almost breathing as I pulled and slackened the line.

I then noticed that if I put the slightest downward pressure on the slack line whilst in my hand, the whole knot would begin to unwind itself before the resumption of tension re-bedded it. This unwinding of the knot would happen over and over when rebaiting the hook, but would go unnoticed during fishing. I wondered if these movements of the knot had anything to do with its ultimate failure...

I tied up a hook with the knotless knot, bedded it, and pulled straight for a break against a set of scales. The knot failed at just below the stated breaking strain of 10lb's. I then tied up the same hook with a new length of the same line, but before measuring its breaking point, I relaxed and re-tensioned the knot hard, ten times, just as it might under the normal stresses and strains of a day's fishing.

The knot broke not at 10 lbs, nor 9 pounds, as you might hope and expect, but at... 


I'm serious, so I'll say it again. It broke at 5lbs against my scales, which is less than half the actual breaking strain of the line, and was the very reason I lost two fish in ten minutes. The first probably to a half a day's constant casting, rebaiting and cumulative weakening before the bite came, and the second to that momentary pause in tremendous pressure when the powerful fish stopped for a few seconds, and sudden resumption of the same shortly after, the shock of which simply cut through the already crushed and weakened line.

Hardly able to believe what I had just done, thinking "shome mishtake, shurely," I did it again, but the result was the same in the sense that the breaking strain was compromised, though this time it broke at 7lb's. The third time it broke at an astonishing 4lbs!  The fourth it broke at just below full breaking strain! The fifth it broke at 9 pounds, and so on, and so on, and so on.  The only way to ensure anything like full breaking strain was to tie the knot and pull it till it broke without relaxing and tensioning the knot once, and that, in fishing terms,would mean tying a new hook-length not after every single fish was banked, but after every single weeding or snagging, or for real security, after every single cast!

It was clear that the knot had absolutely no integrity whatsoever. There wasn't any knot strength to speak of, but only a knot weakness that could not be predicted in any way. The only certainty was its uncertainty, because I never could tell what poundage it would break at. The only thing I could predict with any accuracy was that the knot would always fail before the line did, because not once did the line break above the knot.

I then broke the line without the hook or knot. It was surprisingly strong, and always broke at well over full stated test...

I took a close look at those tell-tale pigtails of line. They were all exactly the length of the piece of line that over wraps the main coils before exiting the eye of the hook, and all displayed exactly the same characteristics no matter what poundage broke them. In all cases the line was perfectly round along the pigtail but flattened like a small spade at the very end.

The same evidence was provided in both cases of lost fish, and all my experiments too, proving beyond doubt that the weakness of a knotless knot lies always at the point where the very last loop down the shank stops, and the over wrapping line that passes up and through the eye of the hook, begins. Movement of the knot in its constant relaxing and re-tensioning, crushes the line at this point creating a cumulative, and ultimately fatal weakness.

The effect is best explained by standing near a wall with your hands behind your back, leaning over at an angle and resting your entire body weight against your forehead. Now, you can feel the force but it doesn't really hurt. Now try to take your head away just an inch, and put it back again, and again. Donk, donk, donk, and it really starts to hurt. That's what life is like for the knotless knot...

It's a knot quite literally, bound to fail.

There is only one way to make a secure and strong knot from a knotless knot with monofilament, and that is to glue it so that movement is impossible. Then you'd have a good knot, but who's going to bother with such faff on a windy morning in mid-January? Not me, that's for sure. In my book, a knot is  hardly a knot at all if it can't be tied in seconds with cold hands and used with 100% glue-less confidence.

So, it's back to my trusted palomar, a knot that has never failed me, and the knotless knot consigned to the bin, its sheer convenience hardly compensating for its singular flaw.


  1. this explains so much,i could not understand why i was having breakages at the hook without any real pressure from my rod it just seemed to part without any force or strain upon it.

  2. Indeed, the lack of force required to break the knot was the very thing that stuck out in all cases. Ian, If there'd been a series of failures against full force of the rod, I'd never have questioned it and put it down to bad luck.

  3. pubeefeBrilliant piece of work!
    Would a bit of heat-shrink not secure it as well as glue? (Must see if it shrinks at flask coffee temperature...)
    Many thanks for the insight,
    Alan Tyler.

  4. Alan, I don't know. I've tied the knot again with 20lb sea fishing line to a big tope hook and watched it closely. It's easier to see what's happening at such a scale, and what is happening is the knot constantly moves if it's not made solid with glue, so I don't know if wrapping it with tubing would stop that movement like glue would.

    I might make a video!

  5. Try the snell knot. Used for tying hair rigs on spade-ends, but it's fine for eyed too.

  6. That's a good idea and I have the hook tyer to make it too. Cheers