Kite Tech Tips: Brummel Splice

[gmb13]

It's not tapered. The brummel shown in the video somewhere around 50% a properly tapered splice and close to strength of a figure 8 knot.

That is just not true.

--
Gunnar

[MartinRaz]

yes, thats, what i need.

i stil do not get, how i can do the pic you show with a brummel?

But as Sandras wote - i can just fold in half and make a figur 8

[Sandras]

Martin,

what do you need to do?

To create a pigtail with loop on one side and knot at the other?
(If yes, a figure of 8 at a doubled line works and takes 20seconds and also looks fugly)

If you want to make something like kamikuzas pictures,
you will have to make 2 Brummel splices (to make the 2 loops) and in the middle of one of the two, you will have to make an additional knot.
(I have standarized my bars/kites and have no need for such)

[Kamikuza]

Oh bad picture sorry. That's just a loop at one end and figure 8 at the other. Dead simple, just a regular eye splice and tie a figure 8 at the other end.
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That was what I meant...

Of course, you can do a Brummell when you have both ends free. When adding a knot, you need to measure your tail bury from the end of the line, decide on the size of your loop and measure from the previous mark, add a knot at the apex, THEN measure the other side of the loop. Then do the Brummell for both ends free...

http://www.animatedknots.com/brummeldemo/index.php

e.g. you want a 1-inch long loop with a knot in the middle.
Measure 10 cm (or 62-80x the rope diameter!) from the end for the bury.
Mark it.
Measure 1 inch, make a small mark and tie a figure 8 on top of it.
Measure 1 inch down for the second mark.
At those two marks, you will "Brummell" the rope and bury the tail.

Then at the other end you'll have to do a Macdonald Brummell or other "one end free" method. You'll also have to jigger the length of your knotted loop to make it look right, if you're OCD enough.

The problem with doing Brummell splices and not simple eye and stitched splices is getting the lengths exactly the same. Can be fiddly...

[Kamikuza]

PS for the obsessive, I wouldn't buy or use the pigtails in the picture. What is that, a 2cm bury? Crikey!

[edt]

It's not tapered. The brummel shown in the video somewhere around 50% a properly tapered splice and close to strength of a figure 8 knot.

That is just not true.

--
Gunnar

I've done destructive testing with my own splices and it's what I've found. I can even tell you where the splice will snap. it doesn't snap right at the bury but away from the bury by about 6cm. I encourage you to do your own testing.

[MartinRaz]

AMAZING - thanx for your help!!!

[OzBungy]

I am wondering why we're talking about Brummel splices at all. They sound cool because they are self locking. The big problem is that they're very difficult to get accurate lengths. All the splice parts use up a couple of centimeters of line and you end up with a short line. Once you have done the splice you're stuck with it. I just tried compensating for the length of the splice parts and did not get accurate results.

A simple bury splice is much easier to do and extremely easy to adjust the length. You just put it next to it's partner line and slide the splice up and down until it's accurate. Don't forget to apply the same tension on the lines when measuring. Tension makes a huge difference in line length.

Length of flying lines is not so critical because you can adjust them with the pigtails. It's still a pain to do that. Length of bridle lines is super critical (especially in foil kites). It's far better to use a method where you can proof and adjust the length before completing the splice.

Once the length is perfect you can hand sew the splice to lock it into place. It only takes a few stitches.

If you're super pedantic like me, use a safety pin to lock the splice then sew it on the sewing machine.

I would have been more interested in seeing Gunnar do a splice on <1mm line. It's really hard to get the end of the guitar string into thin line. I think my record is 1.1mm. I tried 0.8mm and it was too hard.

Just a few other comments on Brummel splices. The method shown puts twists into the line where it passes through itself. That worries me. You can do a brummel splice by passing the long end through and that avoids the twist.

Depending on what google search you look at Brummel splices can be considerably weaker than straight splices. I am inclined to believe that given we're poking holes and putting in multiple twists.

Everybody gets excited about the length of the bury, somewhat reasonably because that is where the strength of the splice lies. I generally make the bury about as long as the splicing tool allowing for convenience. Why would you do a short bury on anything except a pigtail (because pigtails are short to start with and the ends are trapped in lines).

Similarly, there's lots said about how important tapers are. I'm not so convinced. I have seen the result of breaking tests to Dyneema and Kevlar and the break was always a few cm away from the knot or splice. Anyhoo, why wouldn't you taper the bury? It takes all of 30 seconds. Half the fun of doing splices is seeing how beautiful and sleek the end result is.

PS If you want more strength, insert a length of line inside the loop portion of the line. That gives you double thickness on the loop section. It doesn't make the line stronger, but it does increase the radius of the loop section.

[gmb13]

It's not tapered. The brummel shown in the video somewhere around 50% a properly tapered splice and close to strength of a figure 8 knot.

That is just not true.

--
Gunnar

I've done destructive testing with my own splices and it's what I've found. I can even tell you where the splice will snap. it doesn't snap right at the bury but away from the bury by about 6cm. I encourage you to do your own testing.

I am not sure what you have tested, but my own tests on sk99 dyneema say something different. With a blunt splice the a 1.1mm dyneema line with a 10cm bury broke between 380kg and 410kg. That is pretty much at almost 140% breaking strain. With the taper the way I do it, it broke between 410kg and 430kg, which is about 150%. Also statistics and also most literature on this does not support your statement of 50% .

--
Gunnar

[foilholio]

That is pretty much at almost 140% breaking strain.

Thats your problem right there, thats how do you say not possible To be less rude your testing numbers are wrong or the manufactures numbers are wrong, I would say both are wrong with a leaning to the manufacturer.

With the taper the way I do it, it broke between 410kg and 430kg, which is about 150%. Also statistics and also most literature on this does not support your statement of 50% .

I did do a lot of testing on this stuff and edt was in the thread discussing it with me. Now I am not entirely sure what you two are talking exactly about and this is from memory ( not the best). Tapers have little to no effect on strength but not using one would seem to cause long team wear on the line. The brummel itself is about 50% strength and if the tail slips and the brummel gets tight it will weaken down somewhere towards 50%. The strength in a brummel is from the tail. Another good reason for tapers especially with foils is they make the line smooth and less likely to knot and the tail end is less likely to pop out.

Strangely I would say plain splices are more fool proof, but you really need some stitching for that. Brummels though in use seem fine.