Cruising Sailors Forum Archive

Splicing 12-strand Dyneema

This is a follow-up to a thread below regarding the various methods of splicing 12-braid Dyneema.

I am replacing the lifelines with 1/4" Amsteel and looked into the various splice methods. What I find is two recommended methods:

Modified Brummel and Bury as outlined in:

http://www.colligomarine.com/docs/misc/splicing_instructions_for_web_rev_1_2.pdf

The other is Samson's standard tuck and bury splice:

http://www.samsonrope.com/site_files/12S_C2_EyeSpl.pdf

I made a couple of sample splices to see how it went and have some comments.

The Modified Brummel looked tricky in the instructions but actually went quite easily. Once it was done it looked pretty good considering it was my first attempt. One thing that bothers me a bit about this splice is the tension on the terminator part that is buried inside. It looked OK when it was done but I brought it to work and a couple of us passed it around, admired it and "messed" with it. After a while the buried part seemed to develop a bit of slack where it came out of the center. A slight tug on it pulled it out
and left the loop shown. I do not see any way to fix this splice now that it has come out Although Collegio's instructions say no whipping is necessary I think I would put some stitching through the penetration area. It might have also helped if I had put a heavy load on the completed splice before handling it. It would seem the the Modified Brummel depends on the pass throughs for the holding power rather than the "Chinese Finger Trap" effect of the Samson splice.

The Samson splice is also shown. I put in a couple of stitches with dacron twine to hold it. In the finished product I would use 1mm dyneema twine for the whipping as detailed in their instructions.

In both cases I tried a couple of different methods of feeding the tail back down the standing part. Brian Toss's wand did not work very well although I have had good results with it when spicing Sta-Set, etc. A normal fid (the one with the hook on the end) sort of worked but I had some problems snagging some of the yarns. What really worked well was to pull it through with sail twine. I passed the twine through the line about 1" from the end then put 1½" heat shrink tubing over the end. Unlike tape it doesn't leave any sticky tails or pull off. The line was expanded with a standard fid then pulled through with the twine.

My plan is to slice eyebolts to one end of the line to match the existing gate hardware. The other ends where the turnbuckles are now will be adjusted with a 7/64" Amsteel lashing. It is not possible to make the Modified Brummel splice with any hardware attached since the eye has to pass through the inverted hole so it looks like the Samson splice will be the one I use.

I found the Amsteel very easy to work with. Both splices were simpler by far than a typical double-braid splice.

Messages In This Thread