Kite Tech Tips: Brummel Splice

[gmb13]

Prefer this way: http://www.animatedknots.com/brummelmcdonald/index.php

Maybe film it with the camera over your shoulder, so we can see it as we would do it...?

That is exactly what I am doing, I am just using a tool to make it easier. There is no way to do it without a tool on thinner lines.

--
Gunnar

[gmb13]

I'm not a cordell. But I did regurgitate the splicing instruction from Samson rope who makes Amsteel in post above. Respect to you Gunnar for putting the video out there for criticism, but I'm going with the instructions from the guys who make the rope. I'm also going to try to learn from the guys who have had a bad day after breaking leaderlines and halyards so as not to follow in their path.

The Leader I broke did not have a splice in it. Take it or leave it. The instructions from Samson are good, but you will never find a splicing needle for a 1.1mm and .8mm line. That is where my technique of using the loops comes in. So far in almost 10 years of using this splice, I have not had a single one slip or fail.

--
Gunnar

[jakemoore]

I also splice kite line and bridle. For a 1 mm line 10 cm is fine. Samson recommends 63 x the diameter.

[merl]

A 5 mm central depower line needs a 32 cm splice.

I don't think any manufacturer has ever been close to this advice (some loops are amazingly short in fact). Maybe because you don't really need to preserve the full strength of 5mm line in kitesurfing applications (i.e. it is already overkill in terms of strength at around, what, 2000KG?). For kite lines you might be operating close to the breaking strain so maybe it makes more sense there (~10cm bury for a 1.7mm line)

[Sandras]

The Leader I broke did not have a splice in it.

Dumb but honest question : what did it have?
I mean how did it connect to the rest of the equipment?
I bet that to something as thin as a race back line does not like knots...

[fluidity]

Hi Gunnar,
we had a local downwind race with 30 starters and only 5 finishers. One woman broke her ankle/foot before getting into the water, there was terrible turbulence.
I was out maybe 500-800m when in turbulence my upper left rear line looped about 3m into a loop that suddenly formed in my left front line as the kite dipped in a lull and when the kite re-tensioned, the knot completely cut the loop of back line off. I quickly pushed the quick release and self rescued until a rescue boat picked me up. It helped that I'd stuffed a self rescue lanyard underneath my wetsuit before the race, while I was winding my lines and the kite in (took ages with the squalls) I had my board attached via the lanyard. Many people lost boards and/or kites during the race.
A few days later I repaired my lines by doing my own first splices to shorten all lines by 3m.
Your version of the Brummel splice looks elegant but personally I prefer the single long pull or "bury" of the tail through the back of the loop into the cavity between the woven fibres and then stitching across. If it's stitched then I know there will be no creep and of course the outer sheath will tighten around the inner tail under load but there is no way for it to slip. Also, in your version taking the tail through the base of the loop multiple times puts more stress on the twisted fibres in my opinion than the single entry and stitching. Important though to sew with a sharp needle that doesn't have a cutting end. Of course for a thicker leader line there is more strength in the fibres to use your starting method...
Anyway, it might interest you to see the video that one of our 5 finishers (Garrick) made, he was on a 10m kite (I was only on a 9!)
Note how as he is coming up to Somes Island he has full depower, bar out all the way and he has his board sideways for maximum braking!
Graham.
Garrick's video:
https://www.youtube.com/watch?v=HetLeGtRFhY

[jakemoore]

viewtopic.php?f=1&t=2397898&hilit=Splice+fail&start=20

[Kamikuza]

Prefer this way: http://www.animatedknots.com/brummelmcdonald/index.php

Maybe film it with the camera over your shoulder, so we can see it as we would do it...?

That is exactly what I am doing, I am just using a tool to make it easier. There is no way to do it without a tool on thinner lines.

--
Gunnar

You're using the standing line, the animated knots works from the tail. Your method is faster and uses less steps but you're pulling more line through the hole ie. the loop folded over, 4x the line width?

At least, that's how it appears to me which is why I think you should put the camera on your shoulder...or forehead!

I use a similar tool (has a stopper ball on the end so can be "opened") but work with the tail, then put the tool through the loop and then through the hole so it's only pulling 2x the width of line...

My loop tool is fine down to 2mm Amsteel but I generally prefer to use an embroidery hook -- it's just big enough for leader lines. The hook is fine for Lyros steering lines (1.6mm?), but for bridle lines I have to revert to a loop made from guitar wire.

[edt]

All the testing I have seen, amateur testing done by guys here in the forum, testing done by companies, it all indicates that the strength in the splice is in the taper. That taper is one of the worst tapers I have ever seen. Redo the video with a proper taper thank you. Long bury, slow taper, that will give you a 99% splice strength. Quick taper and your line is gonna snap. It doesn't actually snap at the taper it snaps about 5 or 10cm away from the bad splice, doesn't ask me why but that's what I've seen in destructive testing. I had one of my bad splices tested once where I was lazy doing the taper and it had 50% of the strength of another splice, same line, same splicing technique but a much better taper.

[Kamikuza]

All the testing I have seen, amateur testing done by guys here in the forum, testing done by companies, it all indicates that the strength in the splice is in the taper. That taper is one of the worst tapers I have ever seen. Redo the video with a proper taper thank you. Long bury, slow taper, that will give you a 99% splice strength. Quick taper and your line is gonna snap. It doesn't actually snap at the taper it snaps about 5 or 10cm away from the bad splice, doesn't ask me why but that's what I've seen in destructive testing. I had one of my bad splices tested once where I was lazy doing the taper and it had 50% of the strength of another splice, same line, same splicing technique but a much better taper.

That's a bit picky

Any taper has to be better than just cutting it square, like 99% of spliced lines I've seen from manufacturers...!