How good are your knots? Or how good do you think they are? I carried out a short test tonight, mainly for my own benefit but the results were quite interesting so i'm posting them here.
Knots tested:Half blood knot (or whatever it's called, the common one!) http://www.animatedknots.com/improvedclinch/index.php?LogoImage=LogoGrog.jpg&Website=www.animatedknots.com
Uni knot http://www.animatedknots.com/uniknot/index.php?LogoImage=LogoGrog.jpg&Website=www.animatedknots.com
Davy knot http://www.itinerantangler.com/casting/davyknot.wmv
Grinner knot http://www.dorkingas.co.uk/Knots/Grinner%20Knot/grinner_knot.htm
The test line was 3.0kg stroft, that's 6.6lb or 4x tippet. I used this line mainly cause it was a bit thicker and since i was tying some of these for the first times i needed to be able to use it easily. My rig was a 2ft piece of line tied using one knot to a fly at one end and a different knot to an identical fly at the other. The flies were pulled apart in a dead straight line using forceps.
First upHalf blood knot vs Uni knot
And the Uni knot is the winnerSecond upHalf blood knot vs Davy knot
And the Davy knot is the winnerThird upHalf blood knot vs Grinner knot
And the Grinner knot is the winnerFourth upUni knot vs Davy knot
And the Davy knot is the winnerFifth upUni knot vs Grinner knot
And the Grinner knot is the winnerSixth and final testDavy knot vs Grinner knot
And the Grinner knot is the winnerResults Table:Conclusion:I also used a newton meter to measure the breaking strain of the line and the failure point of the knot. I can't remember the exact figures but the half blood knot was around 50% breaking strain and the others averaged around 75-80%.
The davy knot was tied using three tucks as opposed to one shown in most step by steps. You first pass the tag end through the loop, then you will wrap it around the opposite side of the loop (tucks) to create the figure of eight. I had been using two but feel more comfortable with three. The Grinner knot is exactly the same as the Uni knot apart from the line is passed through the hook eye twice, this could be impossible with small eyes depending on line diameter.
I'm definitely going to be using the Grinner knot now for most of my flies, and probably use the Davy knot still for when speed is of the essence or when using very small flies. I think the snap I had last week must have been down to my tying.
Very interesting Scott. I must say I was surprised that the Davy beat the Uni.
Alex
Alex - me too! The grinner seems very strong. Interestingly, when i tied a davy knot at both ends, the line broke before the knots did!
Fachan - seems fair :D I recognise that quote from somewhere :makefun
Interesting research Scott. Thanks for sharing the results. I take it there was no injuries then? :lol:
Any chance of retrying the test with different types of leader material (mono,flouro coated, 100% flouro etc) and post the results here please?
I am a great believer in the double Davy Knot as you know. Its so easy to tie even I can do it when shaking with the cold!
Thanks
I stopped using the half blood months ago after one failure too many. It is easy to tie on short droppers, but that's about all it's got going for it. I am sure knots that are soundly tied and tested start to slip as the nylon absorbs water. Not really a problem for 99% of the fish we normally catch in Scotland but when the big one comes along as they sometime do........a good fish lost on the Don in August was the last straw for me............................. :(
Half Blood Losses 3
Doesn't that just mean you can't tie a half blood :crap
Four turn water knot and tucked half blood is what I use on my casts.
It's great work Scott and thanks for taking the time and making the effort. I'd like to see some tests done on various leader materials comparing and quantifying steady pull breaking strains, shock breaking strains and knot performance. This something I have been meaning to do for years, but have never quite got round to it.
I use a 3 or 4 turn water knot for my droppers and a half blood knot - not tucked - to my hooks. I went back to using the half blood knot after failures with all sorts of other knots... but I reckon that was because I was pants at tying them :(
Norm
I meant to say....
Do you have picture of your set up? I could maybe rig something up at the school (if my work ever gets quieter) and give it a bash myself, in fact it might make a good project for advanced higher - knot strength and different materials - might set up some sixth year with that thought :think2
Norm
You always hear that the half blood knot is just about the poorest knot to secure your gear with and this seems to prove it - but I still keep going back to it.
I've sat with a spool of line and taught myself other knots but when its getting dark and my fingers are cold I can knock out half blood knot with relative ease. Must try harder this winter!
Norm, in order to do this scientifically you need a set up that can be verified as repeatable and finding a suitable (i.e. affordable) transducer / load cell is a problem.
There was a 20 fluorocarbon test done in the 2006 Trout Fisherman magazine (sorry - bought at Schipol Airport airport as I had run out of newspapers). A lot of the fluorocarbons are still around to my certain knowledge. Quite interesting results - Hardy and Drennan are known for their reliability - not surprising as they both broke way over their advised BS but were also much thicker. The test was done in the Masterline factory with very precise machinery and the line pulled at a constant rate until broken.
Guys thanks for all the suggestions, I have done some further testing with different leader materials and will make a post in a couple hours once I have time to sit down and write it out. Will also answer the questions that have been posted. Some interesting twists when leader material is changed....
Quote from: claretbumble on October 14, 2009, 04:25:46 PM
Ooooohh, very good!
We love a good pun on here - that one had me knotted with laughter! We'll need to rope you into the Pun Club (Hon Pres: River Chatter). Or maybe you're a little tied up this afternoon?
For such puns you should be highly strung. :D
Part 2Here we go....
For clarification, the half blood knot i referred to was indeed the tucked version, also known as the improved clinch knot. Also for clarification, to those who say it needs to be wetted carefully and bedded down carefully and i may have tied it wrong - it was tied exactly the way it should be. Remember this is testing to destruction, through pulling force. When playing a fish you exert very little force on the line due to the spring action of the rod. Hence why it seems reliable. I am saying it is not as strong as the other knots tested, probably still fine for fishing (i've never had it fail either!).
The Second Test:Upon request i tested the knots again, pitting them against each other in the same manner. This time however i used:
6lb Airflo G3 Fluorocarbon (3x diameter)
6.4lb Fulling Mill World Class Co-polymer (4x diameter)
Again, as expected the tucked half blood knot was the weakest of the lot. Here's where the major surprise was:
The Uni knot was the second weakest again BUT the strongest knot was determined by leader material. When using fluorocarbon, the Davy knot was the strongest, beating the Grinner knot. When using the co-polymer the Davy knot was the strongest! To ensure this was not an anomoly, i tested each twice.
Further thoughts:I realise everyone has their favourites and that the tucked half blood knot is probably used by most and does well. However this test shows it is infact the weakest of pretty much all the knots that you can attach a fly with. There are more knots than the ones in this list but some are impractical for flies and these seem to be the most common. As i mentioned earlier due to the spring of the rod you actually exert very little force on a fish, and thank goodness for that since the knots seem to reduce breaking strength quite dramatically. People with very, very tippy rods may wish to check which knots they use?!
Conclusion:If using
co-polymer and i suspect most "monofilaments" are nowadays, such as stroft, fulling mill, frog hair etc then the knot strength in order of descending strength is:
- Grinner knot
- Davy knot
- Uni knot
- Tucked half blood knot
If using
fluorocarbon then in my testing the knot strength in order of descending strength is:
- Davy knot
- Grinner knot
- Uni knot
- Tucked half blood knot
Final thoughts:I have limitations to what i can do. I have not carried this out as i would in a laboratory as i simply do not have the resources i would need at home. It was a quick rig drawn up to briefly test knot strength and i found the results worthy of publishing. The other thing was these were the only types of tippet i had around, i've been exclusively using stroft this season. I had the spool of fluoro, don't use it though. I like the fulling mill stuff, seems very strong. I am unable to test the "shock" strength as well, too difficult a setup for my basic experiment!
Norm - i have included a photo especially for you, very, very simple as you can see! I'm sure you were expecting more. The main problem is attaching the line to a newton meter in order to test actual breaking strain. I firstly tied a perfection loop and put the hook through the loop. Turns out that knots to ties loops are even weaker. I ended up holding the end of the line with forceps and then wrapping around the hook of the newton meter around 15 times, this enabled enough grip and breaking strain to test the knot to destruction. Not ideal but was the best i could do. Maybe your pupils could come up with a better one? The photo is not the best, but when trying to photograph the full setup you couldn't see anything. Basically as you see in photo, line tied with one knot to a fly held in forceps and another knot at the other end done the same way. Pull till it breaks :D
(http://i384.photobucket.com/albums/oo290/scottfishing/P1010127.jpg)
Soldier palmers were used as they were cheap flies i never used so no fear of damaging/bending the hook.
One more thing - the Davy knot tied with two tucks is pictured. As you can see it is a tiny knot, bear in mind that is 3x (pretty thick) 6lb fluoro in the photo!
Inspiration - thanks to Alex for the idea, he inspired the idea after a conversation on sunday about the uni knot and davy knot. He suggested the rig and turns out it was a damn good idea.
Good work Scott, thanks for making the effort and attempting to share it with the old dinnae-try-tae-tell-me-anything-new-cuz-I'm-set-in-my-ways-so-I'll-just -do-what-I've-always-done codgers. :lol:
I exclude myself from that group obviously. :makefun
Thanks Scott.
It has confirmed my suspicions that the Davy is the strongest for 100% flouro.
Just as well as I use 4 or 6lb Spiderwire or 4lb Seaguar Red Label :)
Breac - once you start to use the Davy Knot you wont go back to using anything else. :)
Quote from: Pointy Shadow on October 14, 2009, 10:00:38 PM
Breac - once you start to use the Davy Knot you wont go back to using anything else. :)
Or the Grinner if you are not using fluoro :lol:
Quote from: claretbumble on October 14, 2009, 10:48:31 PM
Harrumph.
That Davy Knot looks too simple, and that Grinner looks too complicated. Like Daddy Bear, the Half Blood is "just right" for me! :lol:
You're one of those something-something-codgers Fred was talking aboot aren't you? :makefun
Davy knot looks too simple but is remarkably strong as proved in my test. Try it :shock: The grinner is actually very easy. When i looked up how to tie the uni knot and grinner, i thought feck i'm never going to learn these. 2 mins later i can tie them without reference.
Quote from: Malcolm on October 14, 2009, 12:10:50 PM
2006 Trout Fisherman magazine (sorry - bought at Schipol Airport airport as I had run out of newspapers).
That reads a lot like "Honest dear, I caught it off a toilet seat" ........................... :lol:
Quote from: bordertroot on October 14, 2009, 11:10:17 PM
The grinner is actually very easy. .
How did you manage with one hand Scotty :? :?
After your post I tried it,only thing for me was I couldnt undo it quickly.
Bob
I've got it back Bob! It's a relief to get the dam cast off, so much easier with everything!
Thanks for the description and photo Scott,
If I ever get the chance I'll rummage round the physics gear and see if I can come up with something.
Norm
Scott,
Have you tried the pull test underwater? I was just wondering if the wet strength, as in real word use, was different from dry strength, which you are testing.
I only use nylon and have tried all the knots over the years. The Grinner I felt was just five more operations with freezing fingers that I didn't need (the five extra times through the loop).
I still prefer the tucked half blood :crap
Scotty,
I think there's a problem with the way you are tying the tucked half blood. I've just done a simple test using weights from the kitchen scales as I was a bit worried by the figures you gave. My 4lb (approx 1.8kg) Hardy copolymer with a loop at one end (blood bight) and a tucked half blood breaks consistently at around 1.8kg. Hardy may build in a bit of leeway (see earlier post) but not that much! It's not breaking at the knot but consistently just before one or other of the knots. I can't believe 50% strength if tied properly.
Malcolm
Sandy - will try it this afternoon, very good point!
Malcolm - again good point. I shall try it again and make sure of the results, it does seem common knowledge by searching the net that the tucked half blood knot is the weakest though! Seems strange the contradicting evidence. :?
Breac - i like the look of that, will have to try it and see what the results are.
Malcolm you were right but it is not the knot. I made sure to tie it to perfection.
Stroft's breaking strain is not accurate in the two tests I have just done. One using a spring balance and the other with the kitchen scales. The 4lb stroft broke consistently at 3lb pressure. That was surprising! This was done using a double surgeons loop to create a loop to use. Turns out the double surgeons loop doesn't break before the line, if you're making loops, use that knot! The line broke first.
Will try the other tests later.
The % figures quoted on breaking strain in my first post are inaccurate!
However, it doesn't change the fact that all of the other knots tested are stronger than the tucked half blood knot :lol: For me, i'll be using the double surgeons for loops, the grinner for most flies and the davy for the tiny flies.
QuoteThe % figures quoted on breaking strain in my first post are inaccurate!
However, it doesn't change the fact that all of the other knots tested are stronger than the tucked half blood knot
As you say, Scott, the actual b.s. is irrelevant. What does matter is the relative strength of knot versus knot.
Thanks for doing the tests Scott and sharing that great info. I'll be using mostly grinners from now on instead of the uni knots I have recently been using. I did my own knot v knot test on these two using Rio Powerflex 5X and as showed in your tests, the grinner was the winner.
It must be just me and a lack of practice, but I find the Davy knot easy to get wrong, so I'll be a dinosaur and stick with the knots I can tie. Grinner, uni for NZ droppers and the water/surgeons.
Alex
Quote from: haresear on October 15, 2009, 02:19:28 PM
the grinner was the winner.
Alex,
when you did the test on the grinner knot did you pass the nylon nylon through the eye twice or just once?
Quote from: admin on October 15, 2009, 02:28:07 PM
Alex,
when you did the test on the grinner knot did you pass the nylon nylon through the eye twice or just once?
Twice Fred. Incidentally, I tied the first version of the grinner as shown in Scott's link http://www.dorkingas.co.uk/Knots/Grinner%20Knot/grinner_knot.htm as Scott said, it is just a uni with thee line through the eye twice.
The second version Alan linked to appears to be a different and more complex knot. http://www.sea-fishing.org/fishing-grinner-knot.html - I didn't test this second knot, perhaps I should.
Alex
Alex
Quote from: haresear on October 15, 2009, 02:19:28 PM
As you say, Scott, the actual b.s. is irrelevant. What does matter is the relative strength of knot versus knot.
Thanks for doing the tests Scott and sharing that great info. I'll be using mostly grinners from now on instead of the uni knots I have recently been using. I did my own knot v knot test on these two using Rio Powerflex 5X and as showed in your tests, the grinner was the winner.
It must be just me and a lack of practice, but I find the Davy knot easy to get wrong, so I'll be a dinosaur and stick with the knots I can tie. Grinner, uni for NZ droppers and the water/surgeons.
Alex
YES! Confirmation :lol:
I found the same at first, you have to remember to wrap the tag end on the other side of the loop, rather than the side you passed the tag around first. Hard to explain but i'm sure you follow...
Seems the grinner was not a real grinner, will have to test the real one :shock: It must be super strong!
News just in, the original Grinner i referred to on this page (Uni knot through the eye twice) is stronger than the real grinner. Amazing! Obviously the two turns around the eye provides strength (pressure dissipation?) where the weakest part is. The single wrap round the eye must be the weak point.
It took a fair bit more strength to break a knot this time with these two "grinners" tied. 4lb stroft was used.
Quote from: scotty9 on October 15, 2009, 03:17:38 PM
Obviously the two turns around the eye provides strength (pressure dissipation?) where the weakest part is. The single wrap round the eye must be the weak point.
Very likely and the additional tuck of nylon at the front of the eye with the 1/2 blood is probably a further weak point. Think of a blunt knife? Only problem of course is with small hooks you might not get the nylon though twice, so it will be a uni anyway. :D
**** I'm using nylon as a generic term to cover any leader material!
Quote from: admin on October 15, 2009, 03:28:32 PM
Very likely and the additional tuck of nylon at the front of the eye with the 1/2 blood is probably a further weak point. Think of a blunt knife? Only problem of course is with small hooks you might not get the nylon though twice, so it will be a uni anyway. :D
**** I'm using nylon as a generic term to cover any leader material!
Bang on Fred! Here's some evidence, you can see it was the single strand around the eye that failed.
(http://i384.photobucket.com/albums/oo290/scottfishing/P1010129.jpg)
Col - you should at least try it, it's not
that difficult! :D
I've just done another test with this - still just with tucked half blood - this time with 6lb (2.7kg) Hardy copolymer. Simple set up - loop then a size 8 hook with a bag suspended from it.
[attachimg=1]
[attachimg=2]
Results - 4 pulls - all failed away from the knot. Most failed within an inch of the knot as before which suggests I need to be careful about moistening when drawing up but one broke midway. So in all my tests not once did the knot itself fail!
Weights between 2.92 and 2.95 kg. (2 litres of water = 2.050kg!).
(Edit Meant to say that it seems to me a knot test is only valid for a particular brand of material)
I repeated the 1/2 blood vs Uni 4 times with size 8 hooks and 4 lb Maxima green.
Each time the nylon broke and both knots held.
This, along with what has gone before convinces me that there are just too many variables - hook eye wire diameter, type of leader material, possibly angle of pull, individuals variations in knot tying?????? it needs to be done in a more controlled and repeatable way.
Both right, this was a very, very basic test.
Angle of pull was exactly horizontal.
Personally i think the two most important variables are hook eye diameter and material used. Each material will have different knot holding properties. Anyway, maybe i have gotten everyone to try testing relative knot strength and hopefully everyone will find the strongest for them! :D
Tried above test again with size 14 piranha hooks - the hooks broke................ just kidding Bob... :D..... the results were the same, the knots held, the nylon broke.
Quote from: admin on October 15, 2009, 07:43:46 PM
Tried above test again with size 14 piranha hooks - the hooks broke................ just kidding Bob... :D..... the results were the same, the knots held, the nylon broke.
I think that you can now take comfort in knowing you tie very good knots :D In all my tests, the stroft, fluoro and fulling mill copoly all broke at the knot.
Quote(Edit Meant to say that it seems to me a knot test is only valid for a particular brand of material)
QuoteThis, along with what has gone before convinces me that there are just too many variables - hook eye wire diameter, type of leader material, possibly angle of pull, individuals variations in knot tying?????? it needs to be done in a more controlled and repeatable way.
I think it is a worthwhile exercise to do your very own knot v knot test using the material of your choice. For years I got by with the half blood until I gave Frog Hair and then Stroft a try. My knots just failed time and again and I lost some nice fish as a result. It was Bob Wyatt who suggested the uni knot. I tried it, it worked so I stuck with it.
Both Fred and I used Rio stuff in NZ this Feb and if I remember right, Fred lost a couple of fish on half bloods. He then got to grips with tying the uni knot and I'm fairly sure he had no more problems. Having done tests last night using the Rio stuff I favour, the twice-through-the-eye uni knot seems to be better than the original once through. Thanks initially to Scotty's test and my own subsequent test using the leader material I like to use, I will now be using the improved knot with confidence.
My point is, it is worth doing your own knot v knot test using what you like to use.
Alex
Never had any faith in "Definitive Tests". I use a tucked half blood for all my flies. Can not remember a failure with it in over 40 years fishing. Can see no reason to change.
Tight Lines
I reckon hook size plays a part too. I've always used the tucked blood not (three turn water not for droppers) without much problem, but on larger hooks - bonefish abroad and sex tourists at home - I've found it can come undone. So when attaching larger hooks I now use a uni knot, which hasn't let me down so far. I haven't passed it through the hook eye twice before though, so will give this a try next time. :)
TBH for the vast majority of the fish caught in Scotland a granny knot would do and would never be tested to destruction, however there is always the chance of something better so it must make sense to use the best knot for the tippet material you are using.
I find that passing the line through the eye twice causes the line to kink when the knot is tightened.
This may or may not affect strength, but it certainly does affect presentation.
And anything which aversely affects presentation is a big no-no for me.
Dave
QuoteI find that passing the line through the eye twice causes the line to kink when the knot is tightened.
Do you find this with the uni lnot Dave?
Alex
Quote from: deergravy on October 26, 2009, 09:19:36 PM
I find that passing the line through the eye twice causes the line to kink when the knot is tightened.
This may or may not affect strength, but it certainly does affect presentation.
And anything which aversely affects presentation is a big no-no for me.
Dave
That didn't happen when i did it. I would have thought the kink is caused when the line is pulled around the eye of the hook when it's tightened? I get a really bad kink with the tucked half blood unless i'm really careful. This is something i really like about the davy knot, it doesn't kink no matter what you do :D
Maybe the material affects this too?
Quote from: haresear on October 26, 2009, 09:26:11 PM
Do you find this with the uni lnot Dave?
Alex
Yes, just tried it,
The once-thru-the-eye uni-knot is straight as a die to the hook.
Twice thru the eye and there's a big kink about an inch from the fly.
Maybe I'm tying them wrong
QuoteThe once-thru-the-eye uni-knot is straight as a die to the hook.
Twice thru the eye and there's a big kink about an inch from the fly.
Maybe I'm tying them wrong
I just tried the two versions of the knot again too. The once through is dead straight like you say. I do get a very slight kink by passing the line through twice, but maybe not as bad as you appear to be getting.
Looks like I'll be reverting to plan A. Once through with a uni knot.
Thanks for pointing that out Dave.
Alex
After all the talk in this thread i still find i just tie whatever comes to mind first when i grab the line! Still seem to be favouring the davy knot due to simplicity!
Putting the line through the eye of the hook twice equates to more friction therefore in theory less strength. The weakest part of a knot is at the end of it ( oppisite end from the eye). If there was no friction then all locking knots would have the same strength. An unlocking knot would just unravel.
So I just use any knot and make sure theres plenty of lubrication.
careful WHB, one day you might hook one over 1/2lb. :lol:
Quote from: wildhibroon on November 14, 2009, 01:46:29 PM
http://www.animatedknots.com/photos/uniknot/uniknotR7.jpg = useful Uni-knot pic.
After checking out various sites, & on reflection, I have decided to change from the Blood to the Uni-knot, on the basis that a knot tied round 2 rather than 1 strand of line, is inherently stronger. It's also a simple adaptation from the old habits of a mis-spent lifetime.
PS - just in case, admin...
you are now guaranteed to catch naught but bandies................. its' known as sod's law.............. :D