Advice for testing line with no knots

Started by gstours, November 14, 2020, 02:22:10 PM

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gstours

  Sounds crazy to most,  :-X butt id like to know the actual breaking strength of several spools of mono to know what to expect from the knotted connections.   Currently knots seem to fail before the middle of the line fails so this is why i,m here.... The pulling can be controlled with a mechanical device and a spring scales can record close approximation of the force exerted butt are simple wraps that don't
overlap each other and bound down by tape acceptable?   Just wondered what others have done????
  I,d rather not cut a fairly long piece if not necessary.   Thanks for some good ideas. ???


Wompus Cat

If a Grass Hopper Carried a Shotgun then the Birds wouldn't MESS with Him

gstours

Thanks for the link to a testing procedure.   I noticed the person seemed to test the line using knots...  I want to eliminate the knots  and just test the line.   Just wondering for some outside the box ideas. ;)

Wompus Cat

Just cut the line you use and tie it back together then do the test like in the video .
If a Grass Hopper Carried a Shotgun then the Birds wouldn't MESS with Him

oc1

Quote from: gstours on November 16, 2020, 10:20:25 PM
I want to eliminate the knots  and just test the line.   

Gary, when I want to test the line and not the knot, I wrap the line around two dowels covered with tape about twenty wraps for each.  When you pull you can feel line tensioning on the dowels until it breaks.  But, it still breaks about an inch away from the dowel.  I don't know if it helps, but it makes me feel like i at least tried.
-steve

philaroman

#5
I guess you'd need one dowel center-bored (basically a long/tall wooden thread bobbin)

w/ lanyard going through bore, connected to scale, then to third dowel to pull on

EDIT: please tell me that's enough to describe the picture in my head,
...or somebody more talented, please draw the diagram

re-re-EDIT:  nope... couldn't use a lanyard...  bobbin would spin
need a fixed "D" handle for center dowel...  like a sawed-off shovel handle

jurelometer

I think that line testing machine procedure is take a bunch of wraps around a large cylinder (mebbe a dozen wraps around a 1" rod or similar, no overlap?) on each side and then tie or cleat off,  Then you have to decide how long to soak the line in water, and how slow or fast to pull,  and make sure that the soak and pull are executed exactly the same each time.  Oh, and do several samples, because the line is variable. I have found some of my braid spools to be so variable, that sometimes the line would break before a 70% knot. So it gets tricky.

It will be hard to nail the exact breaking strength, but you should get in the ballpark by using a couple chunks of 1 inch smooth pipe or similar, attached to a scale with some sort of bridle.

If you tie good bimimis, you can get close enough that it shouldn't matter without the dowels if you are testing mono.  Braid, not so much.

-J

Wompus Cat

Throw the Cow over the Fence some Hay .

That is what I am getting in my Cobwebbed old mind  in relation to the reply on the video  from the first post.
If you wanting to test the line strength then the video with the weight in the bucket should work since the line broke in the video and not the Knots on  each end......
If you want to test the knot strength then it would be different scenario .
You say you don't want to use a lot of line.

The only  other way  I can think of  if you want to test the breaking point of the line without any knots is gonna cost you a roll of line to split between two spools then put the spools between the handle on the bucket ,get two peeps to hold the spools without them spinning , then you put weights in the bucket including the weight of the bucket in your final value  when the line breaks without any knots .
Then you can tie the broken line back together and test your knot strength .
Now then tie that back together and you have your spool of line to use just have a knot in it somewhere but you will know when it will break .........lol

If a Grass Hopper Carried a Shotgun then the Birds wouldn't MESS with Him

philaroman

Quote from: philaroman on November 16, 2020, 11:41:47 PM
I guess you'd need one dowel center-bored (basically a long/tall wooden thread bobbin)

w/ lanyard going through bore, connected to scale, then to third dowel to pull on

EDIT: please tell me that's enough to describe the picture in my head,
...or somebody more talented, please draw the diagram

re-re-EDIT:  nope... couldn't use a lanyard...  bobbin would spin
need a fixed "D" handle for center dowel...  like a sawed-off shovel handle

I'm gonna' translate my own verbiage:

use a a sawed-off shovel handle as one of the dowels
put a spring scale where the shovel used to be
pull on the scale  ;D

thrasher

My thoughts would be to take two dowels and drill two holes thru each one. Take a yard of line, go thru first hole wrap a couple times then thru the second hole. Pull tight and repeat on other end tag end. Attach one dowel to scale and tug on other one

gstours

   Tanks for your responses,   ;)   This good news actually,   kinda like several ways to tye a herring... as long as we get fish for dinner thats the main thing rite????
   I,m doing some off season knot testing,, using newly purchased mono for leaders in less than 30 inches tied w a snap swivel on one end and a swivel on the opposite end....   The knots are another topic...... ???
  Firstly I feel a need to establish a baseline value for the mono..... Sounds crazy right????  its 80# right?  it says so on the spool?  No Daa? :-*
     I have been surprised with losing some good heavy fish this year and it hurts a little,  butt sticks in my mind as I could have made better choices...   In the mentioned cases the leader/knot broke and everything changed fast.    Butt in here to learn.
  Most folks might say use heavier everything. :-X    Yes I like an insurance factor,    Butt I like sporty Too. :)

oc1

A guy testing line on another site wraps it around two pieces of 4-inch diameter PVC pipe claiming that a 1/2" metal rod puts too sharp of an angle in the line where it comes off the metal rod. 

I only use light stuff and break it against a spring scale by hand.  Trouble is, my hands starts shaking trying to slowly break 20# so the needle on the scale is bouncing around and the number is suspect.

-ebenezer

Brewcrafter

We may be trying to reinvent the wheel here.  A quick search for "tensile strength testing" revealed a whole raft of ASTM documents (side bet that Jurelometer Dave has already accessed the appropriate document AND understands what it covers :D) and there are machines built to specifically do this kind of testing - and probably every major fishing line manufacturer has one or more in the QA Lab.  Now since a quick search of Tensile Strength Testing equipment ran the gamut from $2000 benchtop models up to $46,000 units (I think those are used for testing things like suspension bridge cable) I think I'm cool with working out something using broomsticks and a spring scale...
In my previous life we had similar equipment to test the tensile strength of paper, since when you have a giant roll of paper funning through a machine running at high speed, the last thing you need is to exceed the tensile strength of the paper web... - john

jurelometer

As  a side note, it is pretty hard to bust off 60 lb mono with a 70% knot.  If the line is  not IGFA rated, we are probably taking around 70% of 70 lbs, which is around 50 lbs of strain.   If you are breaking off at the knot, you need to test your knots wet, and improve or find new knots  that will hold up  to at least 40 lbs or so.  You should be able to go over 50.

If the line is breaking away from the knots,  I would look for harder leader material.   Hardness is more important for abrasion protection than diameter.

As an example, for fly fishing we sometimes need leaders that are highly abrasion resistant, but will still break before the fly line.  The old favorite (Mason) was incredibly tough, on the very thick side,  and ridiculously stiff, the newer brands usually has a softer core, which is a nice compromise.   I still have some 20 lb Mason lying around, and I wouldn't be surprised if it were more abrasion resistant than most 60 lb leaders on the market today.  This is a long winded way of saying that all leader is not the same, and a harder leader might be the ticket if the leader is not breaking at the knot.  OTOH,  harder leader does not knot as easily.

-J