Definitive knot test

[scotty9]

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!

[scotty9]

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.

[Wildfisher]

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.

**** I'm using nylon as a generic term to cover any leader material!

[scotty9]

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.

**** 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.



Col - you should at least try it, it's not that difficult! 

[Malcolm]

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.
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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)

[Wildfisher]

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.

[scotty9]

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! 

[Wildfisher]

Tried above test again with size 14 piranha hooks - the hooks  broke................ just kidding Bob... ..... the results were the same, the knots held, the nylon broke.

[scotty9]

Tried above test again with size 14 piranha hooks - the hooks  broke................ just kidding Bob... ..... 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  In all my tests, the stroft, fluoro and fulling mill copoly all broke at the knot.

[haresear]

(Edit Meant to say that it seems to me a knot test is only valid for a particular brand of material)

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.

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