Author Topic: Fishing Knots - Joining Lines  (Read 43637 times)

jcsampson

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Re: Fishing Knots - Joining Lines
« Reply #60 on: June 29, 2010, 10:27:17 PM »
Quote from: knot4u
"Sheesh, this place is impossible."

They told me that what survives in the end is the good stuff.

I hope that helps.

JCS

knot4u

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Re: Fishing Knots - Joining Lines
« Reply #61 on: June 29, 2010, 11:41:05 PM »
EDIT:  After some testing, I'm finding the Zeppelin Bend to be as good as, or better than, common fishing knots for bending fishing lines.  I didn't even test the Double Zeppelin Bend, which is likely to be even stronger than the Zeppelin Bend.  Also, the Zeppelin Bend jams up in monofilament.  I did not test braided or fluorocarbon. See my Replies #71, etc.
http://igkt.net/sm/index.php?topic=1874.msg13148#msg13148
« Last Edit: July 11, 2010, 07:54:01 PM by knot4u »

roo

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Re: Fishing Knots - Joining Lines
« Reply #62 on: June 29, 2010, 11:50:25 PM »
 If we start comparing knots that jam easily, I'd like to throw into the comparison the Albright Special, the Double Uni, the Double San Diego Jam, etc.  Let's stack the Fisherman Bends up against those knots.
I hope that means you're warming up to the idea of using standard angling knots for fishing line.  That was what this thread was about... I think.

Rope knots and homebrew knots, while certainly possible to tie, just aren't going to be strength competitive with common angling solutions.
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knot4u

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Re: Fishing Knots - Joining Lines
« Reply #63 on: June 29, 2010, 11:56:24 PM »
If we start comparing knots that jam easily, I'd like to throw into the comparison the Albright Special, the Double Uni, the Double San Diego Jam, etc.  Let's stack the Fisherman Bends up against those knots.
I hope that means you're warming up to the idea of using standard angling knots for fishing line.  That was what this thread was about... I think.

Rope knots and homebrew knots, while certainly possible to tie, just aren't going to be strength competitive with common angling solutions.

EDIT:  After some testing, I'm finding the Zeppelin Bend to be as good as, or better than, common fishing knots for bending fishing lines.  I didn't even test the Double Zeppelin Bend, which is likely to be even stronger than the Zeppelin Bend.  Also, the Zeppelin Bend jams up in monofilament.  I did not test braided or fluorocarbon. See my Replies #71, etc.
http://igkt.net/sm/index.php?topic=1874.msg13148#msg13148
« Last Edit: July 11, 2010, 07:54:27 PM by knot4u »

roo

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Re: Fishing Knots - Joining Lines
« Reply #64 on: June 30, 2010, 12:08:45 AM »
 In rope, if we're going to talk about knots that jam, then we might as well borrow some knots from the anglers and compare those.  We're on another topic at this point...
Meh.  I think there are already too many rope knots that jam.

But I don't think certain rope users choose these knots because they jam.  They sometimes choose them because they hope to not be seriously straining the ropes, such that they might not jam.  And there might be some other attribute about the knot that they like, such as extreme security in hostile (stiff, slick) rope, and the knot might just be easy to tie and hard to screw up. 

And so on.
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SS369

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Re: Fishing Knots - Joining Lines
« Reply #65 on: June 30, 2010, 12:58:37 AM »
Something that should be considered while contemplating the joining of these lines is the knot's ability to pass through the eyelets.

SS

Dan_Lehman

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Re: Fishing Knots - Joining Lines
« Reply #66 on: June 30, 2010, 06:28:26 AM »
There's more Replying here than reading & thinking,
and some comments that call for redress.

To one central point --i.e., relative strength of Rosendahl's bend--,
there is some evidence that the Grapevine Bend (aka Dbl.Fish) is
considerably stronger.  A decade ago or so, one fellow did some
homebrew, truck-pulls-knotted-rope-with-knots_A_vs_B in a sort
of competition.  With a few trials for most, he came out with the
Blood knot as a champion, and the Grapevine was also strong;
Rosendahl's Zep. bend was around the middle, not quite so strong
as Ashley's #1452, IIRC.  About these, we can wonder at the exact
geometry taking the force.  (The ends of each specimen were tied
w/Fig.8 eyeknots:  these never failed!!)
((Roo should recall this:  initiated by interest in a presumed invention
of the "Bulldog Bend", which turned out to be Ashley's #1425, which
indeed is a neat knot.))

And from the Treebuzz thread cited by Roo, we have another view:
Quote
When I tested the F8 bend against the ZB, I got 66% and 63% respectfully,
in 9mm PMI rope. I don't even consider 3% enough to claim a difference.
The DFB, however, held to a significantly higher loading and I finally ran
out of room on the machine before it failed.

This is not all so surprising, and quite contrary to
Quote
It seems that that the Zeppelin Bend doesn't put as much stress on a rope as does the Double Fisherman.  The angles in the Zeppelin Bend are not as extreme.
???
To my eye --and to one commenter in the Treebuzz thread--,
the initial bends in Rosendahl's bend are relatively hard, around
one diameter, whereas those in the Grapevine are more gradual
AND each SPart gets gripped pretty firmly by the other.  (E.g.,
in one test of 8mm low-elongation (caving) kernmantle where
a Strangle noose-hitch was tested (i.e., rope turned around a
'biner, and then a "half a Dbl.Fish" was tied to itself), the break
came in the SPart of the noose-hitch, not the knot --so tight
was the knot's choke on the highly loaded line!  (This might not
occur with every rope, though.)

To Roo's dismissal of the witnessed slippage "post rupture" of
the Grapevine:
Quote
When a knot breaks, it breaks.  I'm interested in what the strength percentage is,
not what dance the rope does or does not do afterward.
I'm done trying to think of different ways to explain this.
Security issues only apply before rupture. It shouldn't need to be said.
...
This is not a security issue with slippage, it's what happens after the rope ruptures.

But this behavior is significant, indicating the internal
slippage occurred prior to and so led to the rupture of the mantle
and not the (very strong) core.  Consider that at rupture HMPE
stretches about 4%, but polyester about 10%:  why would the
PES mantle be first to break, then?  --unless the kern's slippage
has left the mantle to do the work (or more than it should)!?
That's my conjecture, anyway.

So, it's not simply some behavior occurring after rupture, IMO;
it has occurred during loading and led to rupture.

Moreover, re
Quote
As I said before, the security issue with slick stiff rope and this knot
is the possibility of things springing open, not slither or slipping.
while I'm unsure of "this knot" --Rosendahl's?--, stiff rope can be
problematic re slipping as turns don't become sharp and nip,
enabling the rope to slip.  (This might explain Richards's results.)


Quote
I'd like to throw into the comparison the Albright Special, the Double Uni,
the Double San Diego Jam, etc.  Let's stack the Fisherman Bends up against those knots.

Firstly, let's forget we even thought about some "Dbl.SDJam"
-- hitching to a hitch is an obviously severe weakening, worse
than eye-in-eye:  1dia turns of highly loaded line vs. line, AND
moving (with force increase).

Secondly, somewhere above I asked if anyone had actually tied the Uni;
my point was that the just-prior-to-tightening images that are commonly
shown present a markedly different form of a multiple-Overhand knot
than seems to be expected to obtain from setting (which would be
the Dlb./Trpl./Quad Fisherman's/Grapevine (and Strangle) form.
So comparing a Uni to the Fisherman's is working with mirrors.
That this isn't recognized speaks to the level of familiarity with
these knots (which to some degree speaks to their presentations).

Quote
But I don't think certain rope users choose these knots because they jam.

Oh, they do.  And they do more:  they tape or hog-ring staple or
tuck-through-the-lay or otherwise secure tails of knots, even of
ones we conclude jam (such as the Fisherman's, noting here though
that Richards's testing found them to slip at high loads).  And
I've read remarks that jamming (well, what would pretty much
be tantamount to this aspect) is deemed good to limit movement
of material within the knot, under load.  (Think *frictional heat*.)

--dl*
====

knot4u

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Re: Fishing Knots - Joining Lines
« Reply #67 on: June 30, 2010, 07:11:32 AM »
Firstly, let's forget we even thought about some "Dbl.SDJam"
-- hitching to a hitch is an obviously severe weakening, worse
than eye-in-eye:  1dia turns of highly loaded line vs. line, AND
moving (with force increase).

Secondly, somewhere above I asked if anyone had actually tied the Uni;
my point was that the just-prior-to-tightening images that are commonly
shown present a markedly different form of a multiple-Overhand knot
than seems to be expected to obtain from setting (which would be
the Dlb./Trpl./Quad Fisherman's/Grapevine (and Strangle) form.
So comparing a Uni to the Fisherman's is working with mirrors.
That this isn't recognized speaks to the level of familiarity with
these knots (which to some degree speaks to their presentations).

First, I tie the Double San Diego Jam like I tie the Double Uni or the Fisherman Bend.  It's not a hitch to a hitch.  We're talking bends here.  Maybe you just don't think too well.

Second, I have tied the Double Uni several times and it's freakin' beautiful.  Maybe you need to practice a little more.
« Last Edit: June 30, 2010, 07:15:15 AM by knot4u »

Dan_Lehman

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Re: Fishing Knots - Joining Lines
« Reply #68 on: June 30, 2010, 07:45:33 AM »
First, I tie the Double San Diego Jam like I tie the Double Uni or the Fisherman Bend.
It's not a hitch to a hitch.  We're talking bends here.  Maybe you just don't think too well.

I think well enough and have asked previously about how this
knot was formed (Roo at least gave the hitch-2-hitch answer;
you, nothing):  there are two ways I could see such a hitch
opposing hitch made:  each hitch *throttles* the other's *neck*,
or they are made (could be made) well apart, and then --yes,
like the Fisherman's Overhand components-- slide together,
abutting each other.  The latter formation doesn't seem at
all good, IMO, for strength or shape; the former would
be trickier to tie.

Quote
Second, I have tied the Double Uni several times and it's freakin' beautiful.  Maybe you need to practice a little more.

Here, again, I've asked (twice) about the form of the component
knots --"freakin'" or otherwise.  And here, too, you've provided no help.

--dl*
====

knot4u

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Re: Fishing Knots - Joining Lines
« Reply #69 on: June 30, 2010, 05:45:46 PM »
or they are made (could be made) well apart, and then --yes,
like the Fisherman's Overhand components-- slide together,
abutting each other.  The latter formation doesn't seem at
all good, IMO, for strength or shape

 ???

The Double San Diego Jam ends up looking almost identical to the Double Uni.  The tying method is similar to that of the Double Uni and the Triple Fisherman.  I would think the properties of all these knots are similar, but the angler knots are built for being able to tie more turns easily.  Also, because the San Diego Jam may be stronger than the Uni, the Double San Diego Jam may be stronger than the Double Uni.
« Last Edit: June 30, 2010, 05:54:34 PM by knot4u »

knot4u

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Re: Fishing Knots - Joining Lines
« Reply #70 on: June 30, 2010, 06:38:41 PM »
To clear up some confusion, some guy on the Internet uses the term "Double San Diego Jam" but is NOT talking about joining lines together.

When I use this term "Double San Diego Jam" above, I'm talking about the bend analogy to the Double Uni and the Triple Fisherman.  My usage makes more sense because the term "Double Uni" is well established to refer to joining lines like this:

http://www.netknots.com/html/double_uni_knot.html
« Last Edit: June 30, 2010, 06:41:39 PM by knot4u »

knot4u

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Re: Fishing Knots - Joining Lines
« Reply #71 on: July 06, 2010, 05:36:28 AM »
Ooops... Here are some test results that go against conventional wisdom.  I just did some testing with the the Zeppelin Bend on fishing line, and the results were surprising.

Using 10 pound test monofilament, I tied a Zeppelin Bend in the same line as an Albright Special.  I used a magnifying glass to inspect proper dressing and started over if I thought a knot was dressed improperly.  I pulled the line on each end until something broke.  The line broke at the Albright Special.

I repeated this test 5 times and received the same result each time.  The line consistently broke at the Albright Special and not at the Zeppelin Bend or anywhere else.  By the way, the Zeppelin Bend jams up in 10 pound test monofilament.

New thread: http://igkt.net/sm/index.php?topic=1902.0
« Last Edit: July 06, 2010, 06:11:46 AM by knot4u »

Dan_Lehman

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Re: Fishing Knots - Joining Lines
« Reply #72 on: July 10, 2010, 06:49:00 AM »
Ooops... Here are some test results that go against conventional wisdom.

To say the least!

Quote
I just did some testing with the the Zeppelin Bend on fishing line, and the results were surprising.

Using 10 pound test monofilament, I tied a Zeppelin Bend in the same line as an Albright Special.
I used a magnifying glass to inspect proper dressing and started over if I thought a knot was dressed improperly.
I pulled the line on each end until something broke.  The line broke at the Albright Special.

I repeated this test 5 times and received the same result each time.
The line consistently broke at the Albright Special and not at the Zeppelin Bend or anywhere else.
By the way, the Zeppelin Bend jams up in 10 pound test monofilament

Good show!

One might question whether you tied the Albright Special correctly;
and, in re "correctly", what is your standard for assessing correctness?

First question, though, is where did the break occur?  (What
sort of loose piece did you have, what did the broken knots resemble?)

Good science demands repetition & verification,
so, thanks to your initiative, I got out some of my bags of discarded
fishline and set about doing a similar test.  I've no idea what strength
the monofilament line is, but it held for a while --in a closed loop/circle--
37.5# of barbell weights, and broke holding the same, just as I was
taking a gander at one of the Rosendahl bends.  I tied TWO of each
knot, in four pieces of line; each side of this closed sling/loop had
one of each knot (AS & RZ) --so I have a survivor of each, to examine.
So, maybe 20-30# line?
It was one of the Rosendahl Zep. bends that broke.  [edit to ad this, um, detail (!) :o]

I found tying the Albright to be a PITA; I used a Geoff Wilson method,
wrapping away from the bight tip 5 times and back the same number
to tuck out the end.  Even with saliva & pliers & nudging, I didn't get
the wraps to draw up fully, and certainly not to close tight the way one
should begin with the method of making all wraps back towards the
bight end (reach far straight, then wrap back).  These sorts of made
or not-made transformations I suspect lead to some various results.

I tied Rosendahl's Z. bend such that each Overhand's tail was pulled
by the other one's SPart away from its SPart --a form I think giving
a nice gradual curvature to the knot.  When I at first drew up one
knot in the easier-to-form version --tails toward respective SParts-- ,
the knot did seem as though it might jam (in such fiddly little stuff);
but the form/version I tied seems readily openable (but right now I
don't want to disturb the survivor).

Possibly, my version of the RZ is less strong than the other, in this
monofilament material.  As best I can tell from the broken knot,
the break came at the bend after passing through the collar, which
is where I'd expect it, at the u-turn.  (But one must be careful in
taking the now untensioned survivor's form as that that
held the full load; there is some recoil.)

In my quick review of some books' info re the Albright, I see that it
is intended for use of tying ("hitching" to a bight, I would say) thinner
line to thicker (or to wire), and sometimes using a "double" --i.e., an
eye knot (Bimini Twist, i.p.)-- for the Albright.  Doing that, of course,
makes the direct comparison to Rosendahl's bend problematic.

--dl*
====
« Last Edit: August 06, 2010, 07:47:10 AM by Dan_Lehman »

knot4u

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Re: Fishing Knots - Joining Lines
« Reply #73 on: July 11, 2010, 02:17:47 AM »
In my comparison of the Zep Bend to the Albright Special, I tied the Albright Special according to a common technique.  I don't know how it's possible to prove to anybody if I tied a knot in 10-pound test correctly.  All I can say is that I tied the knots as best as I could and that I'm pretty good at tying knots.

Note the following:
(1) I tested the knots in my comfy bright home, not on a cold boat that's rocking with the waves; and
(2) If I can't make the Albright Special stronger than the Zep Bend in ideal conditions, then I probably can't make it stronger while on the cold boat.

I'm a little troubled by my findings because, as I understand it, the Albright Special is supposed to be a relatively strong bend for fishing lines.  It makes me have even less confidence with any claims of strength for a particular fishing knot.

When the time comes to bend fishing line for real, I'll probably pull out the good ol' Zeppelin Bend.  I can easily see if I tied the Zep Bend perfectly, and I know that it'll probably be as strong as, or stronger than, any other bend I know.
« Last Edit: July 11, 2010, 03:04:01 AM by knot4u »

 

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