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Re: Double spliced on a short rope?

Posted: Sat Sep 07, 2019 9:48 am
by Herman
Brummels are not really there to lock the tail they are more like insurance. If the brummel has been loaded it will be upset which means the tail has slipped, that is, the splice has failed and you have been riding on your insurance! In practice with all my splicing I have never come across a brummel that imho had been loaded.

Tails are most vunerable to slippage when load is applied gradually and the outer has not fully bitten on the tail. To cater for this stitch the tail in place. You can also use a throat whipping but that method is not commonly used in kitesurfing.

You can also put an overhand knot in the tail to stop low load slippage but I have never seen this recommended in a splicing manual, presumably because of the loss of strength that results from knots.

For experience it is worth playing with short tails and making them slip under light load then tighten them up and retest with high load, repeat with snatched load etc and you will start to appreciate how it works. There is a certain amount of artistry as well as the basic science! Load a brummell with loosened tail and see how it looks.

It could be argued that brummels are almost pointless compared to stitching but it is a bit like arguing that some insurances are almost pointless! Personally I often use brummels in Line thicker than 2mm but rarely use them in thinner line. I hand stitch tails, and only occasionally use knotted tails and throat whippings. Marlows testing indicates that brummels do cause a slight loss in strength with test samples breaking at the lock. That is why I do not use brummels in flying line. (Plus it is easy to get a tight full length bury with flying lines.)

I liked meri's tip, a good idea for strong short connections.

Re: Double spliced on a short rope?

Posted: Tue Nov 10, 2020 2:32 pm
by Oldman
Herman, May I know what sort of hand stitching and type of thread you use?

Re: Double spliced on a short rope?

Posted: Tue Nov 10, 2020 4:52 pm
by Herman
Threads I use:

Polyester V69 for light stuff. ~ upto 3mm line.
Polyester V92 for heavier stuff
Marlow's whipping twine for heavy gear. Comes in various grades waxed or not.

For splices sown by hand I use a basic running stitch. I don't pull them very tight. If I have time I use 2 needles to make the running stitch. If I am doing a repair that requires flex I use a zig zag again done with 2 needles.
If a repair needs flex I use zig zag.

If you want a strong thread you could consider breaking down some dyneema line to use the individual filaments.

I am not claiming the above to be optimal but it has worked for me for many years.

PS Get a sailmakers thread that is UV resistant.

Re: Double spliced on a short rope?

Posted: Tue Nov 10, 2020 9:10 pm
by BartSt

Re: Double spliced on a short rope?

Posted: Wed Nov 11, 2020 7:22 am
by OzBungy
I do all my pigtails as Brummell splices with the tails side by side as shown in the example. It’s possibly the only time that Brummell splices are useful.

I make them in sets so they have to be consistently measured and the same across the pigtails, which is easy, but they don’t have to be an accurate specific length, which is almost impossible with Brummell. For specific lengths, or load bearing loops, I adjust and sew, usually with a measuring jig (length of wood with nails in it)

Pigtail splices don’t need to be super strong because both ends are trapped inside lark’s head knots. As long as they’re reasonably secure they’re fine.

Re: Double spliced on a short rope?

Posted: Thu Nov 12, 2020 2:36 am
by Oldman
found this on the samson ropes site. Will this hold on a short pigtail?

Re: Double spliced on a short rope?

Posted: Thu Nov 12, 2020 9:51 am
by Herman
^^ Presumably Samson does! If you tell me the coefficient of friction between the inner and outer, the coefficient of friction twine on line and twine on twine plus it’s breaking load........

In practice I don’t like using knots as they create a catch and wear point. Considering the diag in step 5 a rough outline of what I do for single needle method for a 3mm pigtail is:

10 ins of thread. Insert needle a B out at 1 leaving 25mm tail. 2 locking loops at 1. Running stitch to A ,~5 stitches. Then back up to 1 @ 90 deg. Then back down to B. 2 locking loops and bury the end to full needle length. Finally I bury the 25mm tail with the needle. I don’t pull the stitching any more than snug.

PS Have a look at the Marlows website!