Author Topic: Uni knot, Nail knot  (Read 14944 times)

Stoatstail

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Uni knot, Nail knot
« on: March 03, 2008, 04:19:41 PM »
A three or four turn Uni knot when tightened appears to take the form of a three or four turn Nail knot when both are used to create a sliding loop, can they be the same? or am I looking at two identical pies with different fillings ?  :)

Fairlead

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Re: Uni knot, Nail knot
« Reply #1 on: March 03, 2008, 06:35:19 PM »
I think you may have a naming of knots problem here - you say when both are used to create a 'sliding loop'.
The Uni (or Grinner Knot) is used to attach a line to the eye of a hook - and yes it could be argued that the part that passes throught the loop is itself a loop, and a sliding one to boot - no problem there.  However the Nail Knot is used to attach a mono fly line to the braided backer and as such is a bend (think of it as a complicated Sheet Bend or akin but different to the Seizing Bend) and so there is no sliding loop as such.
You are right, many knots look very similar when they are pulled up, but you will often find that either the tying method or in inner workings are quite different - one that comes immediately to mind is the tripple (or quadruple) fisherman's noose.

Gordon

Stoatstail

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Re: Uni knot, Nail knot
« Reply #2 on: March 03, 2008, 07:25:10 PM »
In this case the Nail knot is being used to attach line to a hook by seizing against the standing part of the line and is tied exactly as it would be as a bend. Also, the uni is not tied with the initial twists that would normally be seen in the grinner. In cord, when set, the loop lies outside of the wraps and the tag is trapped away from the standing part but, in mono, the knot seems to almost invert and, when set, appears to be very similar to the three or four turn nail knot. Try it.....I'm not good enough with the theory to disect whats going on and would really appreciate some professional insight and analyisis.

Mark   

Dan_Lehman

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Re: Uni knot, Nail knot
« Reply #3 on: March 05, 2008, 06:32:15 AM »
Ha!
I've come to the conclusion that half of the information out there about
these knots is royally confused, and a lot of those presenting the knots
haven't a clue ... .  Have you ever noticed how the completed structure
of an angling knot is typically represented by just an indiscernable
squiggle of turns?!  (Des Pawson is one notable exception in his Handbook,
where there are real-monofil. knot blowups.)  OTOH, discerning structure
in a translucent tiny material w/a mutiplicity of wraps can be challenging;
one netknot--the, or much like the, C-Knuden--was something that took
me some year or so of occasional squinting and finally some couple
of magnifiers & insistence to discern (and now I'm having doubts) in fine mono!

You're right about how in the Uniknot (or is it Grinner? --or either one for the other)
the tying form COULD be the result but for capsizing transformation of the
inner turns to become outer wraps; similarly, for some knots an extended
twisting of  parts is expected to reduce to a single twist and all overwraps.
The Blood knot (bend) is one that can be tied as it's intended to end up
(Barnes calls that "incoil") or in the opposite way (wrapping, i.e.), "outcoil",
which will transform to the former upon wetting & setting.   (I've once seen
someone using the initial/apparent Uni/Grinner form for a Grapevine; I
suppose that it's more easily untied (climbing rope--stuff one can sink
one's teeth into, not fit between the teeth).)

I recall seeing some discrepancy in the reported strength of the Uni/Grinner,
and came to wonder if that resulted from a setting difference, of essentially
apples vs. oranges equated under the label "fruit", so to speak.

I see Geoff Wilson equating Double Uni with Grinner,
which gives a sense to "double" that I've been trying to kill in arborist
circles re the Fisherman's knot (where taking "Dbl.Fish" as here for
"Dbl.Uni" they call the <Strangle Noose (Scaffold Knot)> a "Fisherman's".
argh *&@#^# (Arborist News is supposed have an article addressing
this misnomer.)

I should play around with these knots more, but the fiddly nature of the
line deters me; OTOH, I can get some good quantities of the stuff from
a recycling collection (latest time I got some line of stout monofil with
a braided sheath!?).  Hmmmm, the time might be coming.

 ;)

Stoatstail

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Re: Uni knot, Nail knot
« Reply #4 on: March 05, 2008, 08:42:51 AM »
Hi Dan, tied in 6mm sash the uni wont deform under its own steam, I can get it to do it in 3mm and its much easier to see than in mono when setting.

Stoatstail

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Re: Uni knot, Nail knot
« Reply #5 on: March 05, 2008, 08:01:23 PM »
OK.... Abok 1120 a scaffold knot looks like a nail knot to me and Abok 1121 a gallows knot looks like a uni. Ashley considers these to be different tyings of the same knot. Can someone just confirm this for me please.

Thanks

Dan_Lehman

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Re: Uni knot, Nail knot
« Reply #6 on: March 08, 2008, 11:13:52 PM »
OK.... Abok 1120 a scaffold knot looks like a nail knot to me and Abok 1121 a gallows knot looks like a uni.
Ashley considers these to be different tyings of the same knot. Can someone just confirm this for me please.
Yes, these show the two appearances commonly seen.
Ashley indicates the way to change the 1121 starting form into the finished
form shown by 1120; but absent direct manipulation, the 1121 form could
be sustained in the finished knot, in many (most?) materials.

--dl*
====

TheTreeSpyder

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Re: Uni knot, Nail knot
« Reply #7 on: March 11, 2008, 11:40:28 AM »
i think; that a Scaffold/Noose is better in rope and Uni/Griner (dang that sounds rough!) better in mono.

A Scaffold / Noose is better to me and theories for rope, because the non-Standing Part of the eye enters at the bottom of the Turns (for less deformity f the Standing) then firms the Standing and softens the bend to the primary /main bend of the Standing by the first turn.  It does this by decreasing gradually, the force in the turns as it builds up towards the Standing.  Note, i'm speaking of having 3+ (but 2 is kinda acceptable) Turns; if there is just 1 as in a simple Noose/ maid by on overhad around the Standing to form shrinking eye; the bend of the Standing is more sharp/sudden/ less gradual; and this effect is lost.  So, we want the far superiour Anchor around the Standing (or more) not the Overhand around the Standing.

A Uni/ Griner goes up the center, and then pulls first from the Standing side to perhaps give more deformity/ less inlinedness to the Standing.  Note; inline is the only unmultiplied/unleveraged angle.  But, this effect is lessened by the line going up the center, because the Turns then choke down on it, to reduce it's force.  Also, mono, needs the force to be reduced, before the sharper bend to the Bitters.   Even though in rope i'd think the Scaffold/ Noose builds well; the immediate bend to start the Coil/ Turns would be too fully loaded and unbuffered for mono!