A circumnavigating catamaran

Swingin’ on a Star

I learned three stranded rope splicing in the Boy Scouts, pretty straight forward, but Double Braid splicing… now that’s a horse of a different color. Each double braid splicing guide I’ve looked over is either so sparse that it is confusing or so esoteric that I would need to buy $100 worth of fids before I could even get started. I’m exaggerating of course, but only a little. After trying a couple of different references I think I have gotten the hang of it. I made this guide as a learning tool and reference for myself. Upon reflection I thought it would be a contribution to the public good to post it for others.

To do an eye splice in double braid you really only need a few standard tools:

· Sharp Knife: For cutting (surprise), but do make sure that it is sharp or you will tear up the braid and make it difficult to complete the splice cleanly. A riggers knife with a spike is handy for opening holes in the braid without snagging the yarns.

· Sharp Scissors: A good knife will work in a pinch but some steps are easier to perform with a sharp pair of scissors. Just like the knife, keep them sharp so that you don’t make a mess when cutting.

· Masking Tape: To tape ends while you work and to put a point on ends so that you can more easily feed them up into the braid.

· Ruler: To measure the parts of the rope you are cutting and splicing.

· Felt Tip Pen: A Sharpe or the like works well here. The pen is used to mark off important measurements on the jacket and core of the double braid. We’ll use letters on the jacket and numbers on the core, each increasing as we move away from the bitter ends.

Is it easier to do the splice with the right fid? I’m sure it would be a bit easier to feed the Jacket into the core and vice versa with the proper hollow fid. I can’t say for sure because in the past nine months of looking, I have not found a chandlery that has had anything but huge Swedish fids, which are no real assistance here. The more splices I do the more I find the above basic tools, which everyone has aboard, quite sufficient. You do need to be careful when working the braids to ensure that you don’t snag the yarns or tear up the braid, but this is simple patience.

This splice is a complex set of markings and a simple set of splicings. Once you’ve set it up with the proper marks the splice is actually easier than working with three strand. Double braid is just what it says, a braided Jacket, surrounding a braided Core, usually made of polyester. The Core is actually just like the Jacket, braided and having a hollow center. To make the splice you must first place carefully measured marks on the Jacket (the outer braided cover) and the Core (the inner braided part). Next you separate a bit of the Jacket and Core. Then you feed the Jacket into the exposed Core (creating the eye) and then you feed the Core back into the Jacket. Taper the ends, tighten it all up, and you have an eye splice. Any more explanation will only confuse the first timer, so have faith and follow the steps carefully one time through (preferably on a scrape piece of rope!) and it will all become clear.



The Double Braid Eye Splice

1. Cleanly cut the end of the rope you plan to splice so that the jacket and core are  neat and even. You will need to be careful with the bitter ends until you tape them in a later step. If you find them fraying and unbraiding as you work put a temporary bit of tape on the ends to keep them in order.

2. Measure 22 times the width of the rope back from the end and mark the Jacket with the letter “A” there. For instance, if you’re splicing ¼” rope you would measure back five and a half inches (22 * 0.25 = 5.5). We measure in rope widths because width is the basis for rope strength and thus all of our splice overlap areas must maintain a proper ratio to the width of the rope in order to ensure the appropriate strength in our splice. All of the measurements and marks made are critical to ensuring that the Jacket and Core parts mate up to create a clean and strong eye at the end of the process, so measure carefully. This A location will end up being the end of the tucked in Jacket.

3. Measure 3 rope widths (3/4 of an inch for ¼ inch rope) back up the Jacket from “A” and mark this location as “B”. This mark will be used to align the tucked in Jacket.

4. From the “A” mark measure back the amount of rope that you’d like for the eye when the splice is complete and mark this spot on the Jacket with a “C”. For instance if your eye needs to be 24 inches in diameter to fit around a cleat you should measure at least 24 inches from “A” to “C”. Mark “C” will become the throat (the Y at the loop base) of the splice. Small eyes can be difficult so try an good sized eye for your first splice.

5. From the “C” mark measure back four more rope widths and mark this spot on the jacket with a “D”. This mark will be used to measure the taper of the tucked Core in a later step.

6. Move down the rope 100 times the rope’s width from the “C” mark and tie an overhand knot. As you work the Jacket back and forth in the steps ahead this knot will keep the Core and Jacket aligned at the knot so that you can straighten things out once you’re near the end of the splice process. A lot of Jacket will end up bunched up against this knot.

Steps 1 — 6

7. Separate the braids of the Jacket to open up a hole at mark “C” and gently pull a small bight (loop) of the core up through the hole making sure to pull an equal amount of core from the left and right parts of the Jacket. I use the spike on a rigging knife, or even a sail-makers needle, to gently push the braids of the Jacket aside and to pry the Core up through the jacket. Do not tear up the yarns or unbraid the Jacket or Core. Take your time and protect the integrity of the braid. This step can be hard with some types of double braid but gets easier with practice.

8. Mark the top center of the bight of Core you just pulled up with the number “1”. This mark is a place holder acting as a base for measuring off the other Core marks.

9. Pull the bitter end of the Core all the way through the hole in the Jacket at “C”. You should now have the Core and the empty Jacket separated from “C” to the bitter ends.

10. Slide the Jacket back to expose more Core and place a “2” mark 8 rope diameters up the core from “1”. For ¼” rope this would mean measuring back 2 inches (8 * 0.25 = 2) along the core and placing the “2” mark there. This mark indicates the location where you will begin tucking the Jacket into the Core.

11. Slide the jacket back to expose more core and place a “3” mark 30 rope diameters farther up the core from mark “2”. This requires quite a bit of Jacket scrunching. This mark is the location at which the tucked Jacket will taper to an end.

12. Pinch the last inch or two of the Core into a tight, somewhat pointy, end and tape it tightly with masking tape. This reduced end will allow us to feed the Core back into the Jacket in a later step and keep the core from unbraiding in the mean time.

13. Pinch the last inch or two of the Jacket into a tight, somewhat pointy, end and tape it tightly with masking tape. This reduced end will allow us to feed the Jacket into the Core.

Steps 7 — 13

14. Carefully separate the braid of the Core at mark “2” and feed the pointy end of the jacket into the center of the Core toward mark “3”. Make sure that you are opening a hole up between the braided strands and not in the middle of a strand or yarn. Remember that fibers are the smallest bits of polyester, and that fibers make up yarns, yarns make up strands, and strands are braided to form the Core and Jacket of double braid rope.

15. Work the Jacket through the Core to mark “3” and then carefully make an opening in the Core braid and pull the jacket up out of the Core. This is easiest to do by sliding the Jacket point into the Core, bunching the Core up, and then pinching the Core with the end of the Jacket while un-bunching the Core (like an inch worm making way). Be careful not to twist the Core or the Jacket as you work them together, any twist introduced here will be hard to remove later and may ultimately cause the eye to twist. Tugging on the bitter end of the Core will neaten it up if things get messy.

Steps 14 — 15

16. Cut off the jacket at mark “A” and taper the end of the Jacket by cutting individual braids along the length of the Jacket from “A” back along the Jacket 30 rope widths at even intervals. For ¼” rope this would involve tapering the Jacket from “A” back 7.5 inches (30 * 0.25 = 7.5). For small eyes you may have to shorten the taper giving up strength.

Step 16

17. Hold the Core near mark “3” and pull the Jacket back through the Core until only one rope width of the Jacket is left exposed at mark “3”. Thus for ¼” rope you would leave ¼” of the tapered tail of the jacket exposed at “3”. Be sure that the Jacket end does not work back up into the core as you attend to other parts of the splice. We will pull the Jacket completely inside the core to clean up area “3” in a later step.

Step 17

18. Carefully open a hole in the braid of the Jacket at mark “B” and feed the pointy end of the Core carefully into the center of the Jacket toward mark “D”. Take care not to unbraid or fray either part of the rope.

19. Work the Core through the Jacket to mark “D” and then carefully make an opening in the Jacket braid at “D” and pull the Core up out of the Jacket. The Jacket may bunch up as you work but this is normal. The most difficult bit is working the Core through the Jacket between “C” and “D” where the Jacket is not hollow.

20. Un-bunch and smooth out the Core and the Jacket around the loop from “3” (the throat of the Core side) to “C” (the throat of the Jacket side) until the Jacket to Core unions meet at the top of the loop and the tapered Jacket tail just disappears at “3”. Take time during this step to tidy up the rope by smoothing out the Core and Jacket bits and working out any twists that may have been introduced.

Step 18 — 20

21. With the eye at rest and smooth (as depicted in the previous step) mark the Core tail beneath Jacket positions “C” and “D”. There are two Cores running through the throat here and we are making trimming marks on the one closest to the bitter end (it wouldn’t make much sense to cut the other one!).

22. Pull the core tail until both marks from the prior step appear at “D” and then cut a tapered end in the core diagonally between the two marks creating a new bitter end. This step can be performed by flattening the Core out and cutting diagonally between the two marks with scissors.

Step 21 — 22

23. Work the new Core end back under the Jacket until it just disappears.

24. Hold the rope firmly at the slip knot and roll the standing part’s Jacket back down around the splice feeding the Core/Jacket interfaces into the throat of the splice. If everything was measured correctly you will have a clean and strong eye splice in your hands.

Step 23 — 24

The splice will support strain when pulled on but pushing on it may deteriorate the splice. To eliminate this problem use a needle to sew three or four stitches of nylon twine through the center of the throat of the splice, then turn the rope ninety degrees and do it again. Tie the twine off with a square knot. You can add chafe gear (leather or fire hose) and stitch it securely in place in the same fashion.

Finishing Work

Copyright 2006-2011 Randy & Hideko Abernethy, all rights reserved