Discussion in 'The Splice Rack' started by moss, Mar 1, 2013.
A square knot connecting both ends?
Yes, after your last stitch there should be a thread on each side on the same section of rope. Just bring one thread to the other side close to the other one and tie them together.
I got some 1.5 mm dyneema whipping twine, waxed. The breaking strength is over 200 lbs (pretty sure, still researching the manufacturer's specs). One of the things I gather from watching this thread is that some of the unpredocatable strength of the splice could relate to bad stitching. So I wonder, more stitches might night directly translate to more strength. I do understand, however, that good friction of the rope your stitching increases strength.
So I've got line that has a 200 lb breaking strength and that goes into 5000 25 times. I'm going to experiment with some stitches that have 30 to 35 stitches and get them break tested. Is there some common logic that says that's a bad idea?
I do something similar as Brocky, square knot, leave enough thread after the square knot to push both ends out the opposite side, then trim to leave about 7mm thread ends, light the end with mini-torch or lighter, squish down with your thumb. This leaves a flat disk of melted thread that will never pull through. Be careful of course not to melt any of the stitching. The idea is that the ends are anchored enough that the square knot never loosens.
You can see the melted/flattened ends on the right side of the stitching next to the trimmed rope end
The only thing I don't like about it is how thick the thread is, when you get to the last pass the cordage being sewed will be super hard to push such a big needle thru. I'm thinking if you were stitching a 5/8" bull rope it would be excellent but for 11-11.7mm lines I wonder if the deformation of the cordage fibers would be an issue on your final sewing pass. Worth trying to pull test it.
That sounds like a good plan. Maybe instead of sending them out to be tested, do it yourself at first with a car to see where it breaks.
I'm not sure how stronger thread with less stitches would work. There might be a point where less stitches might not generate enough friction, and only the stitches are holding them together.
When I first read this I thought. "Yes, it will be interesting to see where the car breaks!"
In the past folks have speculated that a high modulus fiber like dyneema might abrade the weaker polyester fibers in the host rope when it's under load. Have no idea if that's a real concept or not for this application.
Petzl uses dyneema in their adjustable bridges and Connect lanyards. There might not be enough movement in the splice for it to affect the rope. I wondered about the larger diameter thread also, but if the stitches are spaced a little it might work.
Edit: if the car breaks first then he must be doing it right!
Thanks a lot for the insight. I am doing my practice stitches on 1/2" stable braid and if things are looking good I may make a friction saver out of the same stuff. The little bit I've done so far seems pretty smooth pulling the needle through with pliers.
It had occurred to me to test using the car and I like the idea of seeing where the break happens to try and learn how to improve the stitching pattern. I only have a small car so I'm a little skeptical that I'll actually be able to break the splice without really shocking the system, which I would avoid doing. For my car's sake!
I'll post some pics and results when I get the chance to. Thanks for being such avid participants in this discussion brocky and moss!
Always need new members in the cult!
The trick with using a vehicle is to be in the lowest gear possible and creep forward very slowly. And anchor to the most solid frame part possible (of course). And keep people and animals clear if stuff starts flying. If you do rip a car in half you will have proved the integrity of your stitching!
It takes a substantial shock load from my 1 ton to break 3/8" tenex that is terminated with a bowline. That's well under 5400 abs.
I think a splitter might be the easiest bet for consistent static breaking, you would just have to drill and thread a hole on the splitting head and one on the frame and put some serious hardware in it to attach the line... that may be a project in the future for me. I think we have a dinky splitter at the shop, but it should be able to break 6k string, right?
Edit: Did you break those well-used eyes yet?
@shankenstein, I'm curious, what type, or how are you stitching, when you are using pliers to do it?
Unfortunately no, have been insanely busy with various projects (book, art etc.) and a broken finger (not tree related) now scrambling to catch up with my tree work customers. I haven't finished my new lanyard so still climbing on my old one that is supposed to be retired ;-) It's doing fine but will be replaced soon.
Just giving you a hard time. Again.
I know you'll let us know how they do when you break them.
@moss; Sorry to hear about the broken finger. I hope it heals quickly and completely.
A good reason to sew your own? I bought two and both looked like this. The top is the front and the bottom one is the back. I don't think any of the locks are inside the cord! Another thing about these loops is they are pictured as if a small eye is at one end of the loop, but the shrink tube is the only thing holding it in this position.
Interesting! Looks like sheyut. Sewing small diameter cord is difficult! Narrowest I've done is 8mm cordage, you have to go with thinner thread and a smaller needle, the thread above looks way to heavy for 6.5 mm cordage. Tension obviously and as you pointed out totally f'd.
Sketchy, I'm not hanging on that.
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