Prusik

[AviD]

Hey guys, I'm using 1/2" (listed as 13mm from NE ropes) with 8mm prusik material but having a problem with the gripping of the 8mm...doesn't seem to cinch down well unless I set it and pull down and OUT. If I pull straight down it doesn't cinch, it just slides. I think part of this is due to the prusik material being very stiff, if it was softer, I think it would cinch and hold, but instead it just cinches and slowly loosens enough where it doesn't stay "loaded"/set and slides too readily.

Debating on going to 7mm to get a little more grip or maybe I need to soak the 8mm in water or something to soften it up and break it in a little?

Any recommendations?

 

[moray]

What knot are you using? By modifying the knot or the prusik material you can certainly get good performance. An extra turn on the knot might be all you need.

 

[Ghillie]

Three wrap prusik?

Be carefull if you try 7mm that is not just accesory cord. Make sure it is rated for life safety.

I have used 8mm that felt more like 9mm and would not grip on 1/2" static kernmantle.

I would try to stay with 8mm and find a softer handed cordage to use. It will be kind of hard unless you can get your hands on it to compare.

DO NOT try to soften up the cordage you have, either physically or chemically. You will compromise the integrity of the cord.

 

[Ghillie]

How is the hunting?

I thought I recognized the name. What cord did you end up using?

Be safe,

Fred

 

[AviD]

Thanks guys.

I'm using Petzl Rescue Cord, 8mm (5/16").
It's pretty stiff cord.

Tying it together with Double Fishermans, but based on reading more I'm probably going to make them Triple Fishermans.

The prusik with 4 wraps (8 total = 4 above and 4 below) is better but still slides. I can lengthen the cord and go with 5 wraps, but I don't think I've seen a prusik (I admit I haven't seen a ton, just in general hunting applications) with 5+ wraps (10+ total).

Just seems like due to it's stiffness it doesn't set and hold when you cinch it. It loosens up and then slides too freely once you relieve the pressure...and if you then pull directly down on it, it just slides freely downward rather than gripping the main line. If you pull OUT and down, it will re-cinch and grab.

No plans on chemically altering it, was just wondering if over time through manual usage it will soften up and become more pliable and therefore grip and lay/hold better.


The problem with shifting cords is I can't feel them...so I'd have to maybe order several test lengths and see how they feel before ordering my supply.


moray,

I was thinking of using a Kleimheist, but haven't tied it/tried it yet. Was wondering if it would give a tighter hold once it's set and won't back out like a prusik.


Ghillie,

Hunting sucks in NJ! LOL

Hard to find property here, hunting a few public pieces and took a doe a few weeks back. Been knocking on doors (since the spring), but keep coming up empty...either leased already or owned by antis. Meanwhile there are 20 deer sitting in their backyards and running in front of their cars...go figure.

I'll keep on knockin, hopefully get lucky sooner or later.

You been out at all?

BTW, I'll be out in your neck of the woods come November...out in Meigs county. Beautiful out there, love the hardwood ridges and ravines or "hollars" are you native Ohio folks call em!

 

[2FatGuys]

There are quite a few friction knots that work well with 8mm on 11-13mm. Don't stick to the prussick if it isn't working for you!

 

[AviD]

I just tested the Klemheist and it works well with the 8mm.
Once loaded/cinched it stays put rather well.

I did just a two turn Klemheist, I'd prefer 3 or 4 but the length of the prusik wasn't sufficient.

Using a 60" starting length, tying Double Fishermans and a 2 turn Klemheist is about right.

I'll probably bump it up to a 72" or 78" starting length to get another turn or two in there with the Klemheist.


If anyone has any additional thoughts, please let me know.


Thanks all!

 

[Ghillie]

Thanks guys.

I'm using Petzl Rescue Cord, 8mm (5/16").
It's pretty stiff cord.

Tying it together with Double Fishermans, but based on reading more I'm probably going to make them Triple Fishermans. The knot efficiency of the double fisherman's is 21-30%, meaning the knot will cause the rope to fail at around 70-79% of it's rated strength. If you are worried about strength, the only tests I have seen where the triple was stronger was in specialty materials like spectra, technora etc.

The prusik with 4 wraps (8 total = 4 above and 4 below) is better but still slides. I can lengthen the cord and go with 5 wraps, but I don't think I've seen a prusik (I admit I haven't seen a ton, just in general hunting applications) with 5+ wraps (10+ total).

Just seems like due to it's stiffness it doesn't set and hold when you cinch it. It loosens up and then slides too freely once you relieve the pressure...and if you then pull directly down on it, it just slides freely downward rather than gripping the main line. If you pull OUT and down, it will re-cinch and grab.

No plans on chemically altering it, was just wondering if over time through manual usage it will soften up and become more pliable and therefore grip and lay/hold better.If it makes it pliable enough to make a difference, I would worry about core integrity of the cord.


The problem with shifting cords is I can't feel them...so I'd have to maybe order several test lengths and see how they feel before ordering my supply.That's a problem I have around here too. Helps to have forums like this to bounce ideas off people though!


moray,

I was thinking of using a Kleimheist, but haven't tied it/tried it yet. Was wondering if it would give a tighter hold once it's set and won't back out like a prusik.


Ghillie,

Hunting sucks in NJ! LOL Bad day of hunting is better than a good day of working!!!

Hard to find property here, hunting a few public pieces and took a doe a few weeks back. Been knocking on doors (since the spring), but keep coming up empty...either leased already or owned by antis. Meanwhile there are 20 deer sitting in their backyards and running in front of their cars...go figure.

I'll keep on knockin, hopefully get lucky sooner or later.

You been out at all?Nope, not yet. Ike blowing through while two of our main guys where in Colorado mule deer hunting SUCKED!!! Hope to get some meat in the freezer this weekend. Then I can take my time looking for a rack.

BTW, I'll be out in your neck of the woods come November...out in Meigs county. Beautiful out there, love the hardwood ridges and ravines or "hollars" are you native Ohio folks call em!

Y'all come on down an' hunt a spell! Maybe you can rustle up a turdy pointer! A'right!

BTW, glad the kleimheist works and you didn't have to order in an assortment of cordage!

 

[AviD]

Ghillie:

The one thing that caught my attention was the following:

The knot efficiency of the double fisherman's is 21-30%, meaning the knot will cause the rope to fail at around 70-79% of it's rated strength. If you are worried about strength, the only tests I have seen where the triple was stronger was in specialty materials like spectra, technora etc.

So we're getting 80% out of the double and what out of the triple?
Is there a knot that retains 95-100% of the rated strength when attaching two similar/same diameter ends?

 

[Ghillie]

Ghillie:

The one thing that caught my attention was the following:



So we're getting 80% out of the double and what out of the triple?
Is there a knot that retains 95-100% of the rated strength when attaching two similar/same diameter ends?

If you are just using nylon, there is no appreciable difference with the triple.

The highest rated knot that I can remember seeing was the figure-nine (stevedore's knot?) and it was only 15% efficiency over the figure-eight at 18%.

Some of my figures come from CMC rescue and some from USC tests and others over the years.

I may be corrected, but I am confident in those numbers.

If a knot or bend has around 20% efficiency and suits my other needs ie. directional loading (butterfly) not easily capsized (figure-eight) or easily tied and un-tied after loading (bowline) I am happy with it.

Sounds to me, unless you just want to play with ropes and knots, you have a set-up that will suit you well for your application and I would be confident in it keeping you safe (as long as your descriptions are accurate )

You might consider posting pictures and info in the outdoor section of the forum. I would be interested in seeing what you are describing.

Be safe,

Fred

 

[AviD]

Here's what I found on the Stevedore knot:

The Stevedore knot is a stopper knot, often tied near the end of a rope. It is more bulky and less prone to jamming than the closely related figure-of-eight knot.

Before tightening:

I'll see if I can take some pics of my setups.

 

[Ghillie]

Here's what I found on the Stevedore knot:



Before tightening:

I'll see if I can take some pics of my setups.

Yep, that is the one I was referring to. I have played a little with it, tying it in some of the same configurations a a figure-eight and found it bulky (as the quote said) and harder to dress than the figure-eight so I thought that the gains in strength ~3% were not worth the hassle.

 

[yooper]

Y'all come on down an' hunt a spell! Maybe you can rustle up a turdy pointer! A'right!

BTW, glad the kleimheist works and you didn't have to order in an assortment of cordage!

Ya know da turdy point buck lives in da U.P. EH