Brummel Burry

C

Clay

Ok, I seem to have versed myself in regards to using the locking brummel, or more appropriatly the mobius brummel (sounds like a splice for a harpoon gun used in whaling). I've bought some of samson's new ice tail to try, I thought if it works well there probably isn't an easier prussik cord to splice when compared to the numerous high tech fiber double braids.

My question I guess is in general to all splices, I understand the taper should be as long as possible to smooth the transition, though how much of the line should be burried, if any, before the taper begins.

Nick, I had found a thread in regards to beeline where you had mentioned brion toss' recommendation of 48 rope diameters for full strength in vectran burry, but is this 48 diameters before taper? or including taper?

As I've mentioned in a previous post it might sound scary someone asking what might be an obvious answer to those of you that know splicing, but that's why I ask. I have tested other splices of mine to failure so I'm fairly confident in my ability. And as other splicers probably already realize, to take full advantage of spliced line for tree climbing it isn't long before you are trying to modify manufacturer's recommendations to fit our needs.
 
Clay,

I have to say that so far I am completely thrilled with the Ice Tail. You are correct in that it splices very easily and holds up extremely well to the rigors of climbing hitches. In fact I have completely discontinued the use of Tenex for eye to eye lanyards due to the fact that the Ice Tail flat out out performs it in every aspect.

As far as the bury goes, why not just cross over your buries and create a continuous piece? This gives the end product a nice round shape and avoids the problem of bury length. This also creates a slightly larger diameter cord to hold onto instead of the smaller 5/16". Just my 2 cents but from what my clients say they prefer the cords done in this fashion.
 
Oops sorry, having just reread your post I think I may not have responded to your question. I usually count down 8 strands prior to tapering the cord. Of coarse this depends upon what cord I am using and what I am making, but generally for 12 strand hollow braids I tend to start the taper at 8 strands. For Ultratech and Beeline I modify this a bit.
 
Well stated. I have been wondering the same thing. Brion Toss seems to bury "oh...about this much" before the taper begins. I am currently climbing on spliced Ice Tail. After the eye is formed with the Brummel, I've got 8" tail to bury. I count down one station on the tail(three pair of right and left hand strands). This should coincide with one station in the standing part and where the bury begins. I count down one more station on the tail and then I begin to taper. I pull two strands at each of three stations for a total loss of six strands. To finish, I ravel and taper about six diameters.
 
Thanks guys, despite my lack of specific detail you have both answered my question very well. So typically you start pulling strands for the taper shortly after it is buried? and then the end is unbraided and cut at an angle for the finish, makes sense.
Rich, I think I saw a thread on MasterBlasters site where you had a detailed description of the locking brummel which explained your overlap or cross over, I like that idea a lot, as said before it gives you a little more meat in the rope and it's consistent through the length.
 
Clay, beeline and HRC both have the strength in the core, you splice them with a brummel, the beeline splice has roughly a 4" bury with a 2" taper, roughly a short fid on the bury, which is the length of a sharpie marker.
 
Careful, guys like me might interpret that wrong. I don't think that is anywhere close to the recommended bury length for a full strength splice in either size of beeline, which both sizes are very different construction (5/16" = vectran core, 3/8" = polyester core).
 
Rich, one more question, if the taper starts so soon how do you bury the tail to get the strands to lay in the right direction?

In any other splice I've done the tail is run down through the standing end and then back out before the strands are cut for the taper. Then the standing end is milked back down to suck in the tail bury, allowing the cut strands to be oriented in the correct direction.

The pictures I had found that you posted for the locking brummel shows the tail strands cut for the taper before they are through the bury section in the standing end. Do you just run the tail beyond where it should lay and milk back the standing end to align the strands?
 
Clay,

I think you nailed it. Once I have the crossover completed I will take out slack in both directions and then mark where each tail comes out of the core. (just mark the tail, not the body of your cord) Then you pull each tail out and cut them just inside where you made your marks. You can then taper both sides. What I like to do is if I started with a 4" crossover (measured when you take the slack out of the cord) I will taper each side for the full 4". After this you will milk both tapers back inside trying to bring both sides in at the same time. (I put a carabiner in one eye and a carabiner with a foot loop in the other eye, this allows me to pull each side and one time) Once in place I will milk from both ends while applying a ton of pressure to set the strands.

Like anything else there are probably 5 million ways to achieve the same result as above, but this way works really well for me.
 
OK! Done... Haven't climbed on it yet but I finished up two I&I loops with samson's "ice tail." They are about 25" long, the shorter the better, and they ended up with about 12" bury using a 4" crossover.

What I don't like about the ice tail is how soft and lose the braid is on top of it being a slippery material that's only a twelve braid (pick points are larger than higher count braid). After the splice was done and I started playing with the loop I started to get strands popping out from my crossover. I pulled the tapered ends back out, taped them up, pulled them back through, un-taped and re-buried. Now they're set, I think because of the sticky tape residue left on them.

...Which got me thinking, has anyone covered/applied anything to the tapered tail ends to prevent this? I though maybe some wax just on the tapered section might help seat the strands and prevent single strands from working free from the group and eventually working their way out of the outter strands. The right wax or maybe some rosin would provide a certain amount of tack keeping the tails set against each other (at the crossover) and in the outter braid.

Any thoughts? Anyone else with this problem?
 
[ QUOTE ]
My question I guess is in general to all splices,...how much of the line should be burried, if any, before the taper begins.

Nick, I had found a thread in regards to beeline where you had mentioned brion toss' recommendation of 48 rope diameters for full strength in vectran burry, but is this 48 diameters before taper? or including taper?

[/ QUOTE ]

If I'm doing a locking brummell, it will typically be about a short fid down the tail, AFTER the lock, before any taperring happens. In the rarer occasions where it's NOT a locked Brummell, I'll go a long fid in polyester and nylon ropes.. It's worth mentioning that Yale's directions recommend a short fid before tapering, and Samson recommends a full fid before tapering, but that Samson just does a straight bury with no crossovers.

As a rule, things tend to be doubled for what Samson refers to as "Class II" ropes...Vectran, Technora, Dyneema, PoBon, etc... They go 2 full fids before the taper. Yale does about the same, but with some ropes they call for a tail FOUR FIDS long...tapering I think after...3 fids? But we'd have to go check the directions for that.

Yes, Brion Toss just simplified it for us and calls it an even 48 (and sometimes 72!) rope diameter (that'd be a 2'-3' bury for 1/2" rope). Those number are the entire tail length. I think Toss recommends 8 rope diameters before starting the taper...that's just about a short fid, too.

I like the splicing talk....keep it up!

love
nick
 
Hello,
A lot of variables here; I'll try to get to all of them. First, there needs to be an untapered section of any tail, as that is the place you have full rope strength; if you start tapering at the crossover, you are giving away strength.
On a related note, immediate tapering also makes it likely that the load — or just random motion — will cause yarns to pull at the crossover, so there's another reason to delay tapering.
For both reasons, about 8d is a good minimum before tapering, though if you have a really loose braid, go further.
Next, the bulk of the tail is not there to provide strength, but to generate friction, and splice tails are, or should be, calculated to generate ample friction even though the tail is tapered. How long the tail needs to be will vary with the slickness and strength of the material, so Spectra, for example, will need a longer bury than Dacron.
Because the tail is there for friction, taping, wax, or anything else added to the rope is likely to act as a lubricant, a friction reducer. Bad idea.
To prevent the taper from coming apart as you cut the strands, one approach, mentioned above, is to pull the tail out after tucking, cut the taper, then withdraw the tail. This works, but (a) it makes for an extra step, and (b) it is very difficult to start the taper as high as I'd like. Remember, a tapered splice, in almost every material and construction, is stronger than an untapered one, and tapers are always more chafe-resistant than blunt ends. So I like to make as long and as smooth a taper as is consistent with friction generation needs. That's why I taper before tucking, but wait to cut the strands until the bury has started, and the each strand is just started into the bury, and a bit turned back, before cutting. That way the braid tends to stay intact.
As for how much to bury, 48d is what I'd use for covered high-modulus (HM) rope. So if I had 1/2" Spectra with a cover, there'd be a 24" tail. 72d is the tail for UNcovered HM rope. So if I have a piece of 3/8" uncovered Spectra, there'd be a 27" tail. The cores, which take all the load, are about the same on both ropes, and the uncovered tail is a bit longer, which isn't a bad thing, without the cover involved to contribute to security.
Note that on normal Dacron and Nylon, double- or single-braid, there'd be a 24d tail, as that's all that is needed for ultimate security in these fibers (indeed, most splicers use 21d, but the longer bury allows for a longer, smoother taper, and the length is much easier to calculate).
Fair leads,
Brion Toss
 
I've only been burying about 3 diameters prior to tapering a Brummel. Though I doubt that this will endanger my 170lbs. + gear, I will discontinue this practice and bury the 8d recommended.
 
Ok, at least 8d before taper, I like that. On a locking brummel should the bury still be lock stitched and whipped?

My wax idea would refer specifically to only about 4" of the tail where the braid would be unraveled and cut at an angle to overlap the opposite tail in a short eye and eye friction cord. I think the right wax might work or as I had mentioned maybe rosin, though I like the idea of wax better. The right wax would be tacky, like a microcrystalline wax. Still a bad idea?

I finished up a job this weekend where I used the new "ice tail." I love it. I kept a pretty close eye on it and had my beeline eye and eye as a backup in case I saw something I didn't like. Had my brother try it "low and slow" so no worries! He's a BIG boy, of coarse I tried it low too, made sure it felt good. Having the tails overlap in the center of the eye and eye works great, it gives the whole cord a fairly even thickness that is much easier to work with, grabbing good when it's needed but unlocks easy even after a fairly quick burn "test" descent.
 
[ QUOTE ]
Ok, at least 8d before taper, I like that. On a locking brummel should the bury still be lock stitched and whipped?

[/ QUOTE ]

Absolutely. If the tail starts to back out, or if it gets snagged by a little limb...bad things could happen. I typically JUST stitch them a few times to hold the tail in. The proper whipping only goes in if it's NOT a locking brummell, customer requests it, or if I just feel a little frisky that day!

I still am not seeing an advantage to waxing or otherwise coating the strands. If I am following you right, you're aim is to prevent the strand-tipsthat are popping out of braid of the rope?

I've found that by doing a longer, more gradual crossover, I can keep them tips in, even in a looser rope like Yalex. Where I tend to get loose ends popping out is where there is a lot of cut strands all in one spot.

love
nick
 
Clay

What friction hitch are you using and what is your set-up in regards to your carabiners, slack tending pulley, clip in points, etc. The reason I tapered so soon was to lessen the thickening or firming effect of the bury. I make a cord that measures 28" end to end when finished. With any less length or any more full size bury the knotting capabilities are reduced and/or the hitch behaves differently due to the stiffness of the legs. I use a 3 wrap 3 braid Vt in the "Strasser style" set up with the mickey mouse CMI pulley tied around 1/2" Blue Streak or Hi Vee. Depending on my mood I also clip both carabiners directly to my bridge with a Petzl Fixe as the slack tender.
 
Hi again,
Oops, forgot to mention how much I like the overlapping tails on small grommets. For one thing, it's the only way to get a maximum length tail, when the circumference is too short to get an optimum one. Plus, as you note, it makes for a constant diameter. It's how we make small grommets for yacht work, too. The nice thing about these grommets is that the load always presses on the cores inside, adding to security, and this compensates for the short tails. There's a practical limit to how small you can make a grommet, but if I was faced with an extremely short tail, my first inclination would be to go with a different construction, like a Loupee [sp?], a larger grommet with seized eyes, or perhaps a multiple Brummel instead of a bury.
We do stitch where the cores dive in, but only to keep the cores from falling out of the rope when there's zero load.
As for the wax, first of all the grommet you use should be built with a stout safety factor — I'd like to see at least 10:1 for this application — so your weight, or your brother's weight, or both combined won't be any indicator of how good the grommet is. But that safety factor should not be willingly compromised, even potentially. So until I see strong evidence that anything you put on that cord will do no harm, I'd leave it off.
In any event, I'm not clear on why it seems desirable. What kind of taper are you putting on the ends? 8d, cut after raveling, and spaced properly, should be pretty firm.
Fair leads,
Brion Toss
 
Clay, can you send me a few feet of your Ice Tail and I'll splice it and send it back...just to see if the way I splice it helps keep the tips from poking out?

PM me if you have a few feet you'd be willing to sacrafice.

Linda at samson tells me that ICE is a 80% technora and 20% polyester. Sounds like it'd be a good hitch cord. Unforunately, she recommended the Class II splice, which just simply won't work for our application!

Brion, when you say grommett, is that a loop? We're talking about an eye-eye configuration here...just to clarify. Everything you're saying about the crossover of the tails still applies...I just wanna keep it clear in my brain. Thanks for dropping in here occasionally! We love having the expertise here!

love
nick
 
My eye and eye measures 25” full length (eyes included). I buried 12” at each end, which includes a 4” crossover in the middle, though I started my taper sooner than 8d. I think I will cut the two eye and eyes I had made so as not to be used and re-make to include the 8d bury of full braid.

What I might try to do to resolve the loose strands from popping is try and leave the tail braided at the end and cut braid strands much like at the beginning of the taper. I think the problem is that this ice tail is so soft, that with the braid and strands unraveled, the center of the eye and eye isn’t as stiff as the rest and allows the ends of the tails to work against each other and out of the standing part. As mentioned, more full tail buried means more friction, and should pull the standing section into a tighter braid that I’m hoping will hold the crossover better.

The ice tail has over a 8k lbs abs, even if my splices are only half as strong as the rope I still theoretically have a 20:1 safety factor for a 800 lbs load! (½ of a ½) Which I know isn’t 100% accurate when taking into account varying friction and uneven loading, but still, more weight than the rest of the equipment I’m hanging from.

As far as specifics, I climb with a distel on a ‘biner through both eyes and a minding pulling in between.
 
You must log in or register to reply here.

New threads New posts

Back
Top Bottom