In the interest of reducing metal fatigue and deterioration of the aluminum casting, I decided to try and find a soft shackle that could replace the SS connection and take its place.
The one below seems to fit the bill and has an aprox fail value of 11k pounds. Adds about 0.5 inches to overall distance from the collar . I’ll replace all in short time. Only item of concern is UV deterioration over time to be monitored.
I’m a huge fan of soft shackles and dyneema. What makes them expensive, and may lead people to worry about whether UV damage makes replacing them cost-effective, is simply that the big, fat knot which serves as a toggle is hard for DIYers to master. That allows manufacturers to charge way more than the true cost. There are alternatives to that for the budget-minded among us.
(Example, the knot just about the mast collar in Gary’s pic.)Those big, fat knots are useful in applications where a flogging shackle might hit and hurt someone, like on the clew of a jib or spinnaker. (Which we don’t have.)
For other applications, it’s relatively cheap and easy to make shackles that use small wood or aluminum dowel pieces for that toggle. I have to get to my boat to get materials to post a how-to, and I’ll come back and do that later in the week.
Also, UV degradation in relatively sun-protected spots like under the sail and canvas will happen slower than elsewhere on a boat.
So I’m with Gary on this one.
-- Bob
I’m a fan of this approach. After replacing Soave’s mast collar last year, I’ve been using dyneema deadeyes.
I’ve observed so far :
Rob…
At the 2025 rendezvous of our Northwest group we tested a soft shackle I made with (as I remember) 1/4" Dyneema and a simple figure eight stoper knot on a friend’s 33. We attached it between a deck cleat and his halyard winch. We were unable to break it or make the knot slip before his fear for his deck cleat overcame his scientific curiosity.
One key to success of any of these knots is to tighten them hard. Dyneema takes a set once hardened and resists slipping much better.
I have several soft shackles made this way on Sandpiper and have never had one slip or fail.
Animated Knots has a good demo on how to tie the EStar stopper knot, developed and tested by Evans Starzinger. It’s a relatively easy knot that’s tested out as good on Dyneema: EStar Stopper Knot | How to tie a EStar Stopper Knot using Step-by-Step Animations | Animated Knots by Grog
For those who want to make their own soft shackles but are worried about the complexity of the end knot, here are two YouTube videos which show different ways to make one with what I previously called a toggle, but is often also called a dog-bone:
The picture above in the link to the second one shows pretty clearly what a dog-bone looks like. The indentations that give it the dog-bone name make it narrower in the center so the loops holding it can’t slip off.
You can buy a pricey one through marine stores. You can also make your own by buying 6061 aluminum rod half again the width of the line you’re using, then rotating it in a lathe or a drill that’s clamped down while grinding the indentations with a file.
If you’re worried about UV, you can also, after putting the shackle in place, wrap velcro around most of it. The hard side adheres well to the line, you barely need to attach the velcro to itself.
Now that I think about it, that may also be a good way to put some chafe protection on a soft shackle passing over rough metal like on our mast collars. Hmm, I’ll have to try that out…
-- Bob
I have found that soft shackles used directly on the castings will chafe and appears that their useful life is dramatically diminished.
I use one on my boom clew in conjunction with a Wichard eye bolt and it works very well. A similar approach would work at the choker block attachment.
The cast mast collar, I have not seen a solution, short of smoothing the edges of the casting holes or wrapping them with rubber banding or rescue tape .
Main sheet block, choker blocks are obvious uses of a soft shackle. Main halyard as well
I have a dingy tow and replaced the lines with dyneema used a smaller line but needed to add a section of double braid exterior where the jam cleat is as that dyneema is slippery
Thor,
How long do your soft shackles last when used on the mast collar casting ?
What thickness dyneema are you using ? Sometimes thinner is better with a tight turning radius.
I’m using 3/16" spliced into a “Rigging Doctor” style deadeye. I’ve modified the recipe to make a 4" deadeye with about 25" of dyneema.
I’m in my first year and haven’t noticed any chafe yet. The assumptions I’ve made is that Dyneema would be safe for use in critical places like this for about 3 years, and that retired pieces would kick around in junk box and eventually get used in a sacrificial capacity.
An idea that seems to work for me. I hope others will chime in if it is a bad idea. Lanolin ( the cheap stuff that is just lanolin… not LanoCote ) seems to form a slippery protective layer on cast aluminum. It lasts about a season because it is very good at filling in pores and when buffed by the rubbing of ropes or a cloth any excess is easily removed. Over-application creates a sticky mess ( ask Soave’s Tides Track ).
I’ve used it in a couple places where it looks like age has taken it’s toll on surface layers in various spots on Soave. I’m pretty sure this would make it very difficult for future owners to paint to improve aesthetics, but I don’t mind the look of aging aluminum.
Experimenting and searching to find stuff that works for me.
Rob…
Thanks. for posting, Bob, because I had the same thought on knots when I saw the beginning of the thread. According to Evans, it is the ONLY stopper knot that is completely secure (won’t slip) with Dynema.
I have been using soft shackles for a few years now. All the reef lines at the mast collar are soft shackles with a low friction ring. Mast tack and clew are as well but so far I can’t bring myself to change out the big heavy shackle at the sail halyard. Carefully filing and sanding the aluminum castings smooth is required or else the soft shackle wont last very long. I haven’t had one break yet.
Tom
Assuming it’s a place where you have a large enough hole to work with, you can always feed the soft shackle through appropriately sized polyester tubular webbing to provide chafe protection.
The tube needs to be just wide enough to let the eye end slide through, and just long enough to leave room for the eye to be opened and slide over the stop knot or dog-bone.
The mast collar eyes have enough room. The aft boom fitting probably doesn’t, unless you’re deft enough to make soft shackles out of really small-diameter line. My fat fingers can handle 3/16ths given enough time and expletives.
-- Bob
