5/16" Dyneema Sling

[Njdelaney]

I got a good deal on some 5/16" Dyneema SK-75 and was thinking of making a small ultrasling with the small SMC rigging ring. The ring is rated for 32 kN and the rope has a tensile strength of 14,500lbs so there is no question about weight bearing. My question is more about abrasion resistance and whether this is something others have done before. This stuff has a blue abrasion resistant coating and I could also put a sleeve on it to mitigate abrasion from bark, etc. Is this necessary or is this overly cautious? I thought it would be nice to have a small and lightweight sling that wouldn't take up much space or weight but would still be up to serious work if need be. I'd appreciate any input before I start.

 

[Boomslang]

I know plenty of guys who use Amsteel slings

 

[flushcut]

Splice one up and see if it works.

 

[Dan Cobb]

I see a problem. The aesthetic of the rope color and ring color isn't very good.

Seriously, if I'm putting much time or material cost into making something, I'll sleeve a high wear area to extend the life of it. For quick and inexpensive, skip the sleeve and make another when it wears out.

I'm not a splicer. Out of curiosity, how long do you estimate to make it?

 

[Brocky]

Some white whipping twine would give it a Fourth of July look. Shock loading is a problem with dyneema, saddle hunters are using uncovered dyneema for lanyards without wear or snagging being a problem.

 

[Njdelaney]

Thanks @Brocky I knew you'd have some valuable input. I can limit the use to mostly static stuff and keep the weight under 200lbs. @Dan Cobb it will end up taking about an hour or two at most. This stuff is very easy to splice.

 

[TheTreeSpyder]

Dyneema UHMWPE has a friction co-efficient almost matching teflon, many times tho as meat of sandwich between polyester(s). Polyester less stretch than nylon but roughly matching strengths and frictions.
Longer rope part before friction, can give dampening in chain that Dyneema does not, sling is only small part of that shock absorption chain's potential. Friction buffer, before another potential bank of shock dampening resource, except if can control run/friction slip to equate to about same i think.

 

[Njdelaney]

Here's the finished product, weighing in at less than one pound. 7' long total, ring at one end, 10 pockets, and a 3" eye on the other end. Whiplock for the eye, lock stitch for the bury after the last pocket. I used what I think is Notch Acculine for stitching because I had it and don't personally like it for throwline. My only concern is that I don't offend any of your fragile aesthetic sensibilities.

 

[SeanRuel]

I seem to recall dyneema having a pretty low melt point, that may be an issue with heat transfer from the ring? Can't remember details, so who knows. Let us know how it works!

 

[Jonny]

I like the eye on the end, never thought to do that with my ultras. Adds a little versatility to it for retrieval if set up right.

Those little SMC rings are nice, really durable and inexpensive.

 

[Quintanana]

I seem to recall dyneema having a pretty low melt point, that may be an issue with heat transfer from the ring? Can't remember details, so who knows. Let us know how it works!

Yes, low melting point. I’d watch the pockets where there is rope on rope friction generating heat.

 

[evo]

My concern is girdling into the bark, I made myself a loopie but only use it for super light rigging. The only benefit of using it vs 1/2 double braid is the weight (or lack there of).

 

[27RMT0N]

My concern is girdling into the bark, I made myself a loopie but only use it for super light rigging. The only benefit of using it vs 1/2 double braid is the weight (or lack there of).

August Hunicke literally just showed this in a video posted yesterday:

 

[evo]

August Hunicke literally just showed this in a video posted yesterday:

View attachment 78808

It does work a treat but I find myself reaching for it on prune jobs or the like when I need a little extra control, I can just keep it on the saddle and bounce around with it BUT the girdling thing is a risk/no fun on pruning work.

 

[27RMT0N]

Indeed. That said, in this video he was hanging entire trees on it, so that's a lot of force on a small sling/area.

 

[evo]

Indeed. That said, in this video he was hanging entire trees on it, so that's a lot of force on a small sling/area.

well keeping the butt on the ground and having a good groundie a flexy pole helps too. just watched it, and while I know what a spar tree can take (or not take) I still have no desire to ride the rigging like that.

 

[dmonn]

I'm very curious about how you spliced the loop at the end. Did you do a lock stitch on one buried "short" tail after the last pocket and then a single end locking brummel eye splice with a buried, whip-locked tail with the other end? If so, did you overlap the tapered buries?

 

[Njdelaney]

I'm very curious about how you spliced the loop at the end. Did you do a lock stitch on one buried "short" tail after the last pocket and then a single end locking brummel eye splice with a buried, whip-locked tail with the other end? If so, did you overlap the tapered buries?

That is exactly what I did. The bury after the last pocket is more than a fid length so I wouldn't necessarily call it short, especially given that it is pretty redundant. Both buries are tapered and they just barely meet. If I did it again, I'd definitely overlap them. I was worried about pulling one of them back in the wrong direction or bunching it up so I opted for caution, which left me a skinny spot that looks less than perfect.