Jump to content


Rope/knot/splice load testing


  • Please log in to reply
1429 replies to this topic

#1401 Ajax

Ajax

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 6,314 posts
  • Location:Edgewater, MD
  • Interests:The sea, women, history, women who like the sea. Racing, crewing, travel, reading, learning.

Posted 21 April 2014 - 04:41 PM

Well, I have Toss' book to carry with me but I just don't see how that's going to help me when I need a knot other than a bowline "right g-damed now".

 

I guess I'd just better find a way to memorize them, sort of like the prayers in Catholic school.



#1402 Essington

Essington

    Newbie

  • Members
  • Pip
  • 5 posts
  • Location:Wyoming

Posted 21 April 2014 - 04:57 PM

How the hell do you guys remember how to tie all of these knots??

 

While the wife and kids are watching TV in the evening, I'm sitting on the couch with lengths of line, fids, a marlin spike, and a stack of knot books ...

 

In another couple of weeks, our frozen lake will become more liquid and I'll be putting the sailing fleet together, so I'll get a chance to

use some of the stuff I've learned on the couch.

 

But the truth is, there are a lot of esoteric knots being discussed here, you might have need of 1 or 2 of them (I'm not counting the knots you use every day) in your particular setup. Identify what you need and learn to tie them, then use them. 

 

I just keep references (notes) about where to find the instructions for particular knots that i only use very rarely, because I only remember the ones that I use all the time.



#1403 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted 21 April 2014 - 05:51 PM

For me, a basic requirement of a "good knot" is that it is intuititive (for me) to tie. That's why I use the zeppelin among all the various bends, because it is the one I find most intuititive. All the knots and splices I use (except one) I can tie from memory in the dark.

The only exception is that I use the icicle for a few particular applications (like attaching a bridle leg to my drogue rode) and I have to look up the instructions everytime. I use it because it is the only one (I have found) that always grips.

I actually think sailors may use more knots than climbers. They use a figure 8, a water knot, a Prusik (or one of the other grippers like the kleimherst), perhaps a butterfly, perhaps a double fisherman.

#1404 Merit Therapy

Merit Therapy

    Newbie

  • Members
  • Pip
  • 1 posts
  • Location:Boston MA
  • Interests:lasers, camping on racer/cruisers, windsurfing

Posted 21 April 2014 - 08:14 PM

I have a question about the red&green tracers in 1/4in amsteel blue. I've done a couple splices leaving them in place, but they're a pain and often pop out. I read that some folks just cut/pull 'em out for the section they're working on. Does everyone do this? Does it have any strength impact?

#1405 pelorus32

pelorus32

    Member

  • Members
  • PipPipPipPipPip
  • 43 posts
  • Location:Melbourne, AU
  • Interests:Soft rigging

Posted 21 April 2014 - 08:48 PM

A pair of dumb questions:

 

  1. What are seizings typically used for, vs. knots, splices and sewn constructions (in the case of wire, swaged and mechanical conections)? I've used them, but I don't see how they are better than alternatives unless there are special cases I don't understand.
  2. Why serve to protect when a chafe guard is easier and more durable? Perhaps something that had to run through a block, though a chafe sleave careful siezed would do as well.

Just curious about practical application. I'm sure their are many places these will work, but I'm not clear on where they are better.

It's an interesting question...You'd probably call many of them service, rather than a seizing. For instance the brummell and splice entry on my lifelines is protected by what amounts to a small length of service. Chafe guard would be hard to retain in that spot...except by use of a whipping...the same beast by another name. Similarly the point where the chafe guard buries into the life line, at the stanchions is also protected in this way.

 

On my spinnaker halyard the end of the chafe guard on the 12 strand Dyneema tips goes through the eye and then buries back inside the chafe guard itself. That is then served over for extra protection and security. It also prevents the eye going into the block ;) Same with the end to end splice that joins the Dyneema double braid to the single braid tip on the tack strop for the asymmetric. The cover bury is provided with additional protection and security by a piece of service. The tack strop seems to get quite a bit of wear and tear so needs all the help it can get.



#1406 pelorus32

pelorus32

    Member

  • Members
  • PipPipPipPipPip
  • 43 posts
  • Location:Melbourne, AU
  • Interests:Soft rigging

Posted 21 April 2014 - 08:49 PM

 

Just checking in. I've had a bit of a glitch prepping samples of splices, bends, and shackles for testing, but I hope to get them all out soon. Our good friends at New England Ropes are standing by, ready to break large stuff.
Re seizings, I can tell you that I have done a few tests with Spectra, seized, and even with very long, absurdly rock-hard seizings, the stuff slipped out at, as I recall, less than 40%. I tried it over service, as well as bare rope; no significant difference.
By comparison, I've tested seized wire rope at approaching 100% efficiency. Am hoping to make some samples, soon, with seized Dacron and Nylon.

G'day Brion,

 

I'm not worried about service/seizing holding the load. Instead I'm concerned that a splice - capable of holding the load in its own right - when seized, might have a hard point which causes a failure. 

 

Well the answer to that is . . . . a very very little.

 

I made of a piece with good splices either end (using the samson taper, which seems to be 100% in much less space than the super long 'colligo' taper).  I loaded it up to 60% of breaking strength, and I then put on two wire seizing's.  One in the middle of the line where there was no tapered core, and another near the end of a tapered bury.

 

attachicon.gifwire1.JPG

 

It broke at the middle one, so that did create the 'weakest point'.  But it broke at 102% of line tensile - statistically equal to 100% - so it was not a significant weakness.  It just found the weakest point, even if it was only .01% weaker than elsewhere.

 

attachicon.gifwire2.JPG

 

I am prepping my boat, so will have less time the next couple weeks, and then be away from my test bench for the summer.

Thanks for that Evans, it seems like the worry is less than I expected, though perhaps it's a matter of fatigue at the exit point?



#1407 Reht

Reht

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 1,555 posts

Posted 21 April 2014 - 09:01 PM

I have a question about the red&green tracers in 1/4in amsteel blue. I've done a couple splices leaving them in place, but they're a pain and often pop out. I read that some folks just cut/pull 'em out for the section they're working on. Does everyone do this? Does it have any strength impact?

I've never seen amsteel blue with tracers in it, but I don't claim to have seen it all (and certianly my experience with 1/4" amsteel is limited).

Tracers are generally just a different coloured thread in the braid and should be treated like any other thread (to my understanding).



#1408 haligonian winterr

haligonian winterr

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 484 posts
  • Location:Halifax, NS
  • Interests:Going Fast.

Posted 21 April 2014 - 10:04 PM

I've seen it, and to the best of my knowledge it doesn't add anything to the strength of the line. 

 

I think I heard somewheres that they act as somewhat of a "copyright"? To show that it is "legitimate" Amsteel.

 

Again, just speculation.

 

HW

I have a question about the red&green tracers in 1/4in amsteel blue. I've done a couple splices leaving them in place, but they're a pain and often pop out. I read that some folks just cut/pull 'em out for the section they're working on. Does everyone do this? Does it have any strength impact?

I've never seen amsteel blue with tracers in it, but I don't claim to have seen it all (and certianly my experience with 1/4" amsteel is limited).

Tracers are generally just a different coloured thread in the braid and should be treated like any other thread (to my understanding).



#1409 allen

allen

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 1,218 posts
  • Location:SF Bay

Posted 21 April 2014 - 10:30 PM

I have a question about the red&green tracers in 1/4in amsteel blue. I've done a couple splices leaving them in place, but they're a pain and often pop out. I read that some folks just cut/pull 'em out for the section they're working on. Does everyone do this? Does it have any strength impact?

They just showed up a year or so ago. I just pull them out.  They are a pain and always get in the way.  They are easy to remove so that is a good thing.  I suspect they are some manufacturing artifact but I never asked so am not sure.

 

Allen 



#1410 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted 22 April 2014 - 12:01 AM

sailrite velcro - straight line shear strength = 6psi.  There is no branding on this.  But it is 25% less than the 'velcro' brand I tested above, and about 50% less that the 3M velcro spec.

 

And a 2-loop without webbing strength of 640lbs (fabric broke), which is about the same fabric strength as the velcro brand.

 

I think it is interesting that the fabric is breaking rather than the velcro bond in the 2-wraps.  Does that not suggest that the sewing/adhesive is more important than we might have thought?



#1411 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted 22 April 2014 - 02:06 PM

I had a conversation with both Sailrite and North about Velcro stitching/bonding.  Both suggested that zig zag was used when there was going to be a sideways load (to the stitch line), but that zigzag decreased the velcro hook and loop bond strength. However neither had test results to support that theory.

 

So, I created three samples.  All with small puller loops sewn on the ends and 5 sq in of velcro to velcro bond overlap area.  One sample had no stitching at all in the overlap area - simulating an adhesive solution.  One solution had two rows of short straight stitching. And one sample had two rows of long zig zag.  I pulled them until they came apart.

 

The sample with no stitching in the bond area was by far the strongest (35% stronger than the straight stitching), and in fact it was the only sample where the velcro fabric broke at the loop rather than the velcro bind pulling apart. I tested two different versions of this sample (one with better sewing at the loop) to be sure and both broke the fabric rather than pulling apart the velcro to velcro bond.

 

Straight stitching was 10% stronger than the zig zag, both having the velcro to velcro bond pulling apart.

 

Message - for strongest bond strength, use adhesive and the least possible sewing in the bond area, and short tight straight stitching rather than zig zag.

 

Attached File  velcrosewing.JPG   381.05K   30 downloads

 

 



#1412 allen

allen

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 1,218 posts
  • Location:SF Bay

Posted 22 April 2014 - 02:17 PM

^^ what are you stitching to?  Is there some webbing or just sewing through the Velcro? I am not understanding the application here.



#1413 Essington

Essington

    Newbie

  • Members
  • Pip
  • 5 posts
  • Location:Wyoming

Posted 22 April 2014 - 03:03 PM

Straight stitching was 10% stronger than the zig zag, both having the velcro to velcro bond pulling apart.

 

Message - for strongest bond strength, use adhesive and the least possible sewing in the bond area, and short tight straight stitching rather than zig zag.

 

attachicon.gifvelcrosewing.JPG

 

In a previous life, I managed a sewing factory that primarily made products for industrial safety ...

 

Regarding hook and loop, whenever we sewed it, we only did so with a straight stitch (actually quite a bit longer than the stitch in your samples) and also tried to keep it either on or as near as possible to the edge of the tape where there is no hook or loop. 

 

Sewing over the hook/loop itself basically removes the section with stitches from service. The thread blocks the hooks from engaging the loops.

 

One other thing we noticed is that there was a pretty large disparity in durability between the domestic and the imported hook and loop products. The domestic product would last quite a bit longer, while the imported product would begin getting weaker and weaker as the loops pulled out and the hooks broke. However, this was a couple decades ago, so maybe the imported product has since improved in quality.



#1414 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted 22 April 2014 - 03:37 PM

^^ what are you stitching to?  Is there some webbing or just sewing through the Velcro? I am not understanding the application here.

Allen, It was just a pure test . . .to see how the stitching effected the hook/loop bond.  I just wanted to learn how best to apply velcro.  It is simulating sewing onto any substrate - webbing or sail cover or sail .  I just did not add bother adding/wasting the substrate.  The question for me know is the best adhesive for this application.  Vecro brand has some specific 'velcro adhesive'.  There are some contact cements recommended for this application, and there are fundamentally three different types of pre-applied adhesive backing. I think North is using the 3M seamstick tape, but am not completely sure.

 

In a previous life, I managed a sewing factory that primarily made products for industrial safety ...

 

Regarding hook and loop, whenever we sewed it, we only did so with a straight stitch (actually quite a bit longer than the stitch in your samples) and also tried to keep it either on or as near as possible to the edge of the tape where there is no hook or loop. 

 

Sewing over the hook/loop itself basically removes the section with stitches from service. The thread blocks the hooks from engaging the loops.

 

One other thing we noticed is that there was a pretty large disparity in durability between the domestic and the imported hook and loop products. The domestic product would last quite a bit longer, while the imported product would begin getting weaker and weaker as the loops pulled out and the hooks broke. However, this was a couple decades ago, so maybe the imported product has since improved in quality.

Yes, I have confirmed both of those - as shown here, sewing decreases the bond.  I was actually surprised the difference between straight and zig zag was only 10%; and the 'no brand' is not as good in several technical regards (initial bond strength and repeat bond strength are significantly worse, the fabric strength is just a little worse) as the 'brand' velcro.

 

North does (apparently) use zigzag when the load is going to be parallel to the sewn line, even in velcro.  I have some of that on my mainsail in the leach batten pockets closures.  You just need to know the velcro bond will be less.



#1415 allen

allen

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 1,218 posts
  • Location:SF Bay

Posted 22 April 2014 - 03:54 PM

^^ what are you stitching to?  Is there some webbing or just sewing through the Velcro? I am not understanding the application here.

Allen, It was just a pure test . . .to see how the stitching effected the hook/loop bond.  I just wanted to learn how best to apply velcro.  It is simulating sewing onto any substrate - webbing or sail cover or sail .  I just did not add bother adding/wasting the substrate.  The question for me know is the best adhesive for this application.  Vecro brand has some specific 'velcro adhesive'.  There are some contact cements recommended for this application, and there are fundamentally three different types of pre-applied adhesive backing. I think North is using the 3M seamstick tape, but am not completely sure.

.

I don't see how this applies to the case with webbing.  With longer sections of Velcro you are going to get more holding power and at some point will exceed the strength of the Velcro fabric.  At that point you need the webbing for strength and you need to transfer that force to the webbing.  It could easily be that a loss in strength of the Velcro bond is not as important as an increase in strength of the webbing over the Velcro fabric.  If the adhesive is still the answer, it needs to be stronger than the Velcro fabric.  If it is not, then sewing could make the assembly stronger.  Perhaps I still don't understand.



#1416 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted 22 April 2014 - 04:17 PM

Allen, all other things being equal, higher velcro to velcro bond strength cannot be a bad thing.

 

The velcro to velcro bond, and the velcro fabric strength, are both quite weak at their best case - apparently only 5-8psi, and 40-150lbs.  That should not be hard to exceed with adhesive.

 

But if we do need sewing, we know to use as little as possible in a way that disturbs the hook area as little as possible.  That implies some distinctive sewing patterns.

 

>>With longer sections of Velcro you are going to get more holding power and at some point will exceed the strength of the Velcro fabric.<<

 

mmmm . . . the psi will be the same with length.

 

More wraps will give you more holding power, primarily because the load is cut (as in a tackle).  That does not increase the psi.

 

There is a secondarily compression effect (about half of the 'tackle effect') that does increase the psi, but that extra force appears to be transferred to the webbing by the compression and does not require a lot of bond strength to accomplish that transfer. (this all assumes low stretch webbing).

 

At least that is how I interpret my findings so far.



#1417 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted 22 April 2014 - 07:15 PM

^^ just to put the above a bit simpler . . . The failure mode on my sewn webbing Velcro straps is the Velcro to Velcro bond slipping . . . So working on increasing the Velcro to Velcro bond strength seems like the natural place to look for improvement :)

#1418 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted 22 April 2014 - 08:25 PM

duplicate from tramp thread . . . 
 
Just coming back to this - pull out load of 3/8" stainless spur grommet in 4 layers of 18oz shelter-rite fabric (a typical tramp border). 340lbs.
 
Attached File  photo 1.JPG   37.65K   3 downloads
Attached File  photo 2.JPG   36.94K   1 downloads


#1419 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted Yesterday, 11:34 AM

Allen (and others),

I was chatting with someone about soft shackles yesterday . . . Have you ever made/tested any shackles from tenex (or any other polyester hollow braid)? If so, do they fail in the same way at about the same % of tensile? Since polyester is more tolerant of bends/knots I was thinking they might do higher % of rated tensile.

#1420 thinwater

thinwater

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 301 posts

Posted Yesterday, 02:14 PM

^^ I've used polyester stropes for years, and tested a few. Failure is generally by shearing the knot off, though if the tail is doubled they will sometimes fail at the eye, always over double line tensile. However, I was testing used line, just for my curiosity about failure mode, and the numbers were aproximate. I used 5/16" strope for a genoa for years (1500-pound working load) for years, until switching to Amsteel. It did not look worn, just old.

 

I always used a double fishermans as a stopper, though something larger might be better. Mostly I use them to secure covers and tarps, for which they are...

  • Cheap. Always made from left overs and retired line.
  • Fast to make and use. Simple enough to fabricate in-place.
  • Large enough to handle. Smaller Amsteel is anoying.
  • Knots large enough they won't pass through grommets.
  • Won't scratch, like a carabiner would.

Generally the eye is fixed (does not noose shut). In practice they don't shake off (never in years) and they are easier to handle, because they cannot invert.

 

---

 

I do use Amsteel shackles for clews and where smaller size matters.



#1421 allen

allen

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 1,218 posts
  • Location:SF Bay

Posted Yesterday, 02:43 PM

Allen (and others),

I was chatting with someone about soft shackles yesterday . . . Have you ever made/tested any shackles from tenex (or any other polyester hollow braid)? If so, do they fail in the same way at about the same % of tensile? Since polyester is more tolerant of bends/knots I was thinking they might do higher % of rated tensile.

I do have one Tenex soft shackle someone made for me as a gag. It is a foot in diameter and made from 1/2 inch line.  It was in exchange for the Lash-It soft shackle I made for him the year before.  On Papoose, I have used tenex line shackles where I have the opening eye at the end of a Tenex sheet or other control line.  I take those to Amsteel stopper knots.  These were always 7/16 Tenex and I have not tested them.  I like Tenex.  I find it has the nice qualities of Regatta braid but is not even close to as snag prone.  It is also very inexpensive and quite strong.  It has about the same stretch as double braid but gets it with more stretch as a percent of breaking strength but a higher breaking strength.  Only buy the white color.



#1422 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted Yesterday, 05:14 PM

Ok, just for fun . . . some 5/16" regatta braid . . . Broke at 175% of line tensile (which was higher than most dyneema as I expected, but not as much higher as I expected, but that is explained by the failure mode being different), it broke at the line exiting the noose (an odd place to break I thought).

 

Attached File  dacronsoft1 - Copy.JPG   288.88K   19 downloads

 

Attached File  dacronsoft2 - Copy.JPG   260.25K   20 downloads

 

I like the feel of them. I am going to make 3 or 4 large size ones for the boat for utility purposes.  5000lbs is decently strong.  

 

Edit: note - this is a standard diamond soft shackle. Given that the break is not at the knot, the 'stronger design' (in dyneema) would apparently not be stronger in this Dacron (after only one test).



#1423 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted Yesterday, 06:06 PM

By the way, I have been playing around with the 'rat tail' with Grog. It's a gripper, like the prussik or rolling or icicle.

 

It is a nice gripper - intuitive to tie (unlike the Icicle, at least for me), and puts a nice clean pull on the line (most of the other grippers bend/distort the line).

 

But the tying/dressing needs to be right or it does not work at all.

 

Here is one that did not work - with the 'loops' too spread out'.

 

Attached File  rat2.JPG   43.4K   9 downloads

 

Here is one just tied/unloaded that will work

 

Attached File  ratA.JPG   159.89K   10 downloads

 

And here it is loaded up

 

Attached File  RatB.JPG   159.41K   10 downloads

 

Here is an icicle at the same load as the above

 

Attached File  icilce.JPG   42.88K   7 downloads



#1424 allen

allen

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 1,218 posts
  • Location:SF Bay

Posted Yesterday, 06:35 PM

Ok, just for fun . . . some 5/16" regatta braid . . . Broke at 175% of line tensile (which was higher than most dyneema as I expected, but not as much higher as I expected, but that is explained by the failure mode being different), it broke at the line exiting the noose (an odd place to break I thought).

 

attachicon.gifdacronsoft1 - Copy.JPG

 

attachicon.gifdacronsoft2 - Copy.JPG

 

I like the feel of them. I am going to make 3 or 4 large size ones for the boat for utility purposes.  5000lbs is decently strong.  

 

Edit: note - this is a standard diamond soft shackle. Given that the break is not at the knot, the 'stronger design' (in dyneema) would apparently not be stronger in this Dacron (after only one test).

I am going way out on a limb here but is it possible that Amsteel slips through the nose to equalize the load and the Regatta braid binds up in the crossover?  Tenex might do a little better as the surface is smoother.  It is not fuzzy like Regatta braid.



#1425 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted Yesterday, 08:42 PM

^^ perhaps . . . It may also be that I was not very careful about tying the legs exactly the same length, because I am used to (in dyneema) the diamond slipping enough distance to equalize things, but the load here does not pull much rope out of the diamond. In fact you could (I just did) untie the diamond. . . The friction is so high it just does not tighten up the way it does in dyneema.

Based on my Dacron knot testing, I was expecting about 210-220% here. I will make one more, more careful sample. It is somehow much easier to make in this rope, perhaps it is the larger diameter than we are used to working with in dyneema.

But I did think it nice that the "Dacron crowd" can also use all the neat single braid rope tricks (like the soft shackles) we have been using in dyneema.

#1426 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted Yesterday, 09:08 PM

Ok, I just broke a more carefully constructed one - it broke at 200%, and it broke at one of the pins (10mm dia, with 8mm line) and not at a shackle feature.  So I think our 'theory' is correct, and with a careful construction and bigger pins, we have a (roughly) 220% potential here.  It 'should be' a pretty close toss up between breaking at the diamond knot vs the noose.

 

Attached File  dacron2.JPG   217.74K   10 downloads

 

By the way, on another but similar topic . . . .was reading Samson's catalog to find their dacron 12 strand hollow braid product alternatives, and notices a section on joining lines that said that a simple 'loop to loop' join (one loop spliced thru another spliced loop) was 90-100% strength.  This conforms exactly with our test results related to 1:1 bends (where I pulled a lot of 'loop to loops').   But it went on to say that two loops joined by cowhitching was 85%.  I was a bit surprised by that.  I have not tested it but did not think it would be weaker than the 1:1 loop to loop.  I believe them :), so there must be some sort of turn or compression or torque in the cowhitch construction that knocks some strength off.



#1427 allen

allen

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 1,218 posts
  • Location:SF Bay

Posted Yesterday, 09:19 PM

^^ I talked to them once about splicing Amsteel to XLS and the way they recommended doing it was back to back eye splices.  I didn't want the added bulk so did the splice on my web site but it does have that cosmetic issues with hernias.  Their assertion was that you cannot splice two lines with such dissimilar stretch characteristics.  I think they test things pretty well so I trust them as well.



#1428 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted Yesterday, 09:34 PM

Yes, "back to back eye splices" is what I meant by "loop to loop's".

 

In the above dacron shackle, the two legs both broke evenly - which is a good sign for the construction quality.  The diamond was harder to untie, but I still was able with a spike without too much work.  There was some melting at the "noose" pass thru and it was no longer sliding freely - a quick jerk free-ed it - it looks like this was perhaps a blue tracer thread that melted - not sure if that might be polypropylene as none of the main white dacron threads seem to have melted.

 

Anyway, I think it is sort of exciting that  these work so well in dacron (in efficiency terms even better than in dyneema) -  and 6000lbs is a lot of load on most boats.



#1429 thinwater

thinwater

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 301 posts

Posted Today, 10:55 PM

You might try breaking one of these, tied in any scrap of small polyester.

 

I often tie these from parachute cord or scraps to secure tarps and such. But this is also the style I used on my genoa clew for a year. Perhaps a 200 year old style.

 

Strop+002.jpg

 

 

And I've used a few of these. Notice where it broke (in the line). The stopper was MUCH larger before loading. Also used long ago, with the eye splice in 3-strand and a wall knot for a stopper. For sail ties I use covers from 4- to 6-foot scraps (single braid!), bury splice an eye, and leave just enough core in to make a fat stopper; very easy to use and never jam. The flat braid really grabs the stopper, yet they are easy to remove.

 

loop+test,+5-16th+after+low+res.jpg



#1430 Estar

Estar

    Anarchist

  • Members
  • PipPipPipPipPipPipPip
  • 5,145 posts

Posted Today, 11:09 PM

>> For sail ties I use covers from 4- to 6-foot scraps (single braid!), bury splice an eye, and leave just enough core in to make a fat stopper; very easy to use and never jam. The flat braid really grabs the stopper, yet they are easy to remove.

 

Do you have a picture of one of these.  I think I know what you mean . . .  it sounds like you somehow know exactly what length to make them, where as my sail ties need to be much different lengths depending on how well I flake the mainsail.






0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users