Dyneema rigging on a budget

[flyingnut40]

This is a new thread to continue a dialog that was started here

https://www.cruisersforum.com/forums...ng-231269.html

For anyone who wants to follow my quest for synthetic rigging at a SS price... feel free to follow along as I unravel the mysteries of synthetics and why plastic costs more than steel!

A bit of background on me.... I'm selling my house this spring and then going boat shopping for something a bit better suited for retirement. I'm looking for a boat of around 35'-36' and since it will have to be an older boat, I fully expect to put re-rigging the standing rig at the top of the list. Rigs seem to be the one thing that people neglect as the boat gets significant mileage on them and they go to market with old rigs more often than not.

This is actually a benefit if you think about it... you get to start your ownership with a known variable. I have never been comfortable with guessing how much life is left in a rig, and a survey saying rig appears serviceable is not much comfort.

So for me zero timing the rig is a plus and if the price is reduced to reflect that, all the better!

As an avid DIY type, I get my hands dirty on a lot of projects and I think my back yard engineering skills are reasonable, but if you have any constructive advice, I am willing to learn from others.

Until I actually buy another boat, this is considered prep work.

Until I prove otherwise, I will be using Endura 12 SK75 rope in 3/8" and 3/16" for the lashings. R&W Ropes have a good (sale) price on this stuff and once I get my test setup going, I'll have a better informed opinion on how much stretch will be needed to factor in to not having heat stretched DUX.

I have read that heat stretching the rope actually damages it a bit and that creep is less on non-heat stretched rope, but I only read that once and it seems counter intuitive. YMMV.

I have enough 3/8" to rig a typical 35' boat and I have ordered a 10,000 lb. load cell and a 3000# chain come along for testing.

3/8" Suncor thimbles are under $3 a piece at Fisheries Supply for making the deadeyes using a similar technique to James of Zingaro if you have seen his videos.

The problem I'm having with deadeye construction is the undersize burry as 3/8" should have a burry of 72x.375"= 27" on each burry... that's a large deadeye!

I saw a video by Kraken that used a smaller line and more turns that looks promising that I want to try, but unless it passes the pull test I'm not going to suggest using it. It'll be fun to experiment with my idea. I want my deadeyes to be short yet have properly buried splices. More on that later.
but I do like the shorter look of Brian Toss's Signature Series deadeyes.

O.K. Let the flames begin...…

[BjarneK]

I really like your project on reasonably priced synthetic rigging. A couple of points:

Have you considered using Acera: https://www.cruisersforum.com/forums...ra-197606.html ? I don't know how accessible it is where you live. It is of course nice to get a good deal on the rope somewhere, but if you can find a good rope with a consistent low price, that might also be available when you have to replace the rigging after a number of years.

It seems that heat set Dyneema requires a large bend radius, but not standard SK-75/78. This seem like a big advantage to SK-75/78 since it puts much less restrictions on the fittings. Maybe it is even possible to splice the rope straight to the tangs on the mast (like these https://www.riggingandhardware.com/i...H%2075-436.jpg). I think the pins on the tangs might be big enough for that.

It should be possible to make the lashings with a thin line with many turns, but I would feel safer using thicker line for the lashings, so it would take more to break in terms of chafe or something similar. I would aim for around half diameter like you are doing.

[Benz]

Well, I'll jump over here as well, I guess.
Are you talking about using 3/8" for the lanyards? That's rather huge. 3/8 would be the diameter of the shrouds for a 34-36' boat; your lanyards should come in at 1/4" at the most; 3/16" would be more reasonable. You can bury the tail of the lanyard deadend 8" with a brummel--it's more than sufficient. Actually, you could put brummelled splices with different lengths of bury on your test bench and see how long a bury you really need.
@Bjarnek plain sk 75 or 78 will suffer both stretch and creep: that's why DUX was invented. There's also Vectran, which I use for shrouds, but it MUST be protected from the sun. On the plus side, vectran is usually far cheaper than any of the Dyneemas.

[flyingnut40]

Welcome along Benz. Just to be clear, 3/8" shrouds and 3/16" is what I have for the tensioning tackle.

I suspect the need for toggles are mostly redundant with synthetic but still useful for adapting the chain plate to the dead eye.

The dead eyes look like dog bones and take the spot a turn buckle would.

I asked Suncor what the breaking strength of their thimbles were in tension as I would love to eliminate the dead eye dog bone and go direct from chain plate toggle to lashing thimble, but then you loose the fail safe feature of the dog bone. BTW the gal at Suncor said the breaking strength of the thimble was the rope or wire. She missed the words " in tension" I am willing to test a thimble to destruction, on the bench, but unless it is stupidly high I'm not sure if I want to trust it. At least the thimbles wrapped in dyneema can't completely fail and are in compression.

As for using many smaller strands instead of one, remember they add up and instead of one 18,000 pound line many might total 30,000 or more. I'm willing to test to see.

Benz, what's the smallest dead eye (dogbone) you would trust in 3/8"?

Is the 72x rule just for plain burry?
How much can that be reduced with the locking brummel?

Benz, thanks for your inputs.

[Franziska]

I redid Lady Rovers rigging with 8mm Dyneema 2018.
Our rigging is fairly simple though, no spreaders.
Simple splicing exercise and not really complicated once you know how to do it.

The complicated part is though to get everything tightened enough when splicing.
You really want it already tight as possible at the start.
Even Dyneema will stretch a little in the first season. It's not the actual fibers stretching but rather the weave and splices setting in.
It's tricky to know upfront how much it will give.

The way you splice it makes it physically virtually impossible to slip, it just pulls everything tighter, but it can not pull through as far as I can see.
As you mark the location of the buried ends anyway, you have a chance to see where it is by close observation of the taper.

I had to redo some splices in 2019 due to the settling in and we actually did add some rigging screws than. It's just so much easier to adjust tension with them.
As the bottle screws are low down weight is less of an issue.
We had looped Dyneema strings previously and it was always a pain to adjust.
As said it is important to have easy means of tightening in season 1 & 2.

So far we are very happy with the results.
Heat shrink over splices works well, but you want to use as little heat as possible and best use the heat shrink tubing with the lowest shrinking onset temperature you can get.

Guess all in all its a project one can tackle after a few test splices.
What might stop some though is the questions which might come up from insurances, but that's a different subject.

Good luck to all who give it a shot. We are happy with our results.

[BjarneK]

Originally Posted by flyingnut40

As for using many smaller strands instead of one, remember they add up and instead of one 18,000 pound line many might total 30,000 or more. I'm willing to test to see.

I agree that you can add the strengths for the smaller strands. What I am saying is to not go too far. Imagine have lots of turns of a 1 mm strand. Sure, if you have enough turns the strength will be plenty, but it just takes a break anywhere along the 1 mm strand for the lashing to fail. This could happen due to chafing going unnoticed or an accidental cut by something sharp. I am sure you could use thinner lashings than 3/16", but I would maybe be a little uncomfortable using 1/16" for example.

[Jim Cate]

Originally Posted by BjarneK

I agree that you can add the strengths for the smaller strands. What I am saying is to not go too far. Imagine have lots of turns of a 1 mm strand. Sure, if you have enough turns the strength will be plenty, but it just takes a break anywhere along the 1 mm strand for the lashing to fail. This could happen due to chafing going unnoticed or an accidental cut by something sharp. I am sure you could use thinner lashings than 3/16", but I would maybe be a little uncomfortable using 1/16" for example.

And, the more turns in the dead eye, the harder it is to adjust the length.

Jim

[mikedefieslife]

Why do people even use lashings? Why not some appropriately sized SS eyes and regular turnbuckles. Much faster and easier to adjust without messing around with bits of thread

I was thinking of running dyneema on some areas my lifelines, I'll use regular pelican hooks. Easily adjustable minimum messing about.

[Benz]

Originally Posted by flyingnut40

Welcome along Benz. Just to be clear, 3/8" shrouds and 3/16" is what I have for the tensioning tackle.

I suspect the need for toggles are mostly redundant with synthetic but still useful for adapting the chain plate to the dead eye.

The dead eyes look like dog bones and take the spot a turn buckle would.

I asked Suncor what the breaking strength of their thimbles were in tension as I would love to eliminate the dead eye dog bone and go direct from chain plate toggle to lashing thimble, but then you loose the fail safe feature of the dog bone. BTW the gal at Suncor said the breaking strength of the thimble was the rope or wire. She missed the words " in tension" I am willing to test a thimble to destruction, on the bench, but unless it is stupidly high I'm not sure if I want to trust it. At least the thimbles wrapped in dyneema can't completely fail and are in compression.

As for using many smaller strands instead of one, remember they add up and instead of one 18,000 pound line many might total 30,000 or more. I'm willing to test to see.

Benz, what's the smallest dead eye (dogbone) you would trust in 3/8"?

Is the 72x rule just for plain burry?
How much can that be reduced with the locking brummel?

Benz, thanks for your inputs.

I think we need first to clarify terms so that we're talking about the same thing. When say a "deadeye," I'm talking about the thimble with holes in it that you feed a lanyard trough to tighten up a shroud. The upper deadeye has the shroud spliced around it; the lower one connects directly to the chainplate, usually by means of a pin. So it goes thus: the chainplate has a lower deadeye attached to it. A lanyard consisting of several (3 min) turns of thin line is threaded between the lower and upper deadeyes; the upper deadeye has the shroud spliced around it. Super simple. No more parts. The shroud is tightened by pulling the lanyard tight, which is like a mini block-and tackle (in fact, I think you just called it a tensioning tackle). You can lead the tail to a winch to get really good tension on it.
72x is for a plain bury--I would use this if splicing the shroud without a brummel. This is ultimately stronger than a brummel, regardless of bury length. The reason your lanyard doesn't need such a bury is because you're using a brummel, which prevents initial slippage, and you're not putting anywhere near working load on the lanyard, especially on the deadend leg which gets the least amount of pull (you'll see why when you tighten one up).

Lastly, the smallest lashing I would trust is 3/8" is 3 turns of 1/8" That makes six legs. Do the math--it's probably as strong or better than the 3/8"

[flyingnut40]

Originally Posted by Benz

I think we need first to clarify terms so that we're talking about the same thing. When say a "deadeye," I'm talking about the thimble with holes in it that you feed a lanyard trough to tighten up a shroud. The upper deadeye has the shroud spliced around it; the lower one connects directly to the chainplate, usually by means of a pin. So it goes thus: the chainplate has a lower deadeye attached to it. A lanyard consisting of several (3 min) turns of thin line is threaded between the lower and upper deadeyes; the upper deadeye has the shroud spliced around it. Super simple. No more parts. The shroud is tightened by pulling the lanyard tight, which is like a mini block-and tackle (in fact, I think you just called it a tensioning tackle). You can lead the tail to a winch to get really good tension on it.
72x is for a plain bury--I would use this if splicing the shroud without a brummel. This is ultimately stronger than a brummel, regardless of bury length. The reason your lanyard doesn't need such a bury is because you're using a brummel, which prevents initial slippage, and you're not putting anywhere near working load on the lanyard, especially on the deadend leg which gets the least amount of pull (you'll see why when you tighten one up).

Lastly, the smallest lashing I would trust is 3/8" is 3 turns of 1/8" That makes six legs. Do the math--it's probably as strong or better than the 3/8"

So Ben,
What you are calling a deadeye, I am calling a thimble with lashing holes in it.

I would love to skip what Kraken calls a deadeye (like the dogbone) and go directly from chain plate to lashing loop (Colligo deadeye) but I would need about 20 of those at deck level and 10 more up top.... that's how we get to spend thousands on rigging....

I wish I could trust the Suncor thimbles in tension and use them with a toggle and lash to that but there would be no failsafe. This would be so much easier with pictures.....


toggle that to chain plate and run lashing from the upper thimble to the lower stay thimble for tensioning.

[flyingnut40]

like this.....



I would love to turn the thimble around and skip the deadeye, but at this point I don't trust the thimble enough to use it in tension. The cross section is about 1/9 of a square inch so 80,000/9= 8888.8 lbs/ x2 = 17,700 lbs.

it should work, but I would want to see a thimble break test first.

[Benz]

Ah, I see now....Kraken has introduced another layer of confusion by calling his thimbled strop a "dogbone". There are other things people are calling dogbones, which consist of a bit of rod spliced crosswise in a line. You slip a loop over that for a quick connect. Traditionally these are toggles, and that's I sell them as. Google Tylaska Dogbones to see. But the pics explain it all.
Anyhow, I see your question, and the solution is to not put a thimble in tension, but to use a regular bow shackle on the chainplate, and feed the legs of the lanyard through there. You can splice your shroud around a closed thimble and use it as an upper deadeye--it's just harder to keep the turns from riding over each other, which is why I like the Colligo ones, which separate the legs of the lashing enough that I can twang individual legs as I tighten. You can use a Colligo one for the upper deadeye, and a bow shackle for the lower--I do it in some places where I couldn't elegantly get a lower deadeye--hrm-distributor, to go. A glance though my website and blog will show plenty of pictures of this in action.
At the upper end of the shroud, there's no reason to use fancy thimbles, just regular closed rope thimbles will do. The're like $5 apiece.

[Benz]

Originally Posted by mikedefieslife

Why do people even use lashings? Why not some appropriately sized SS eyes and regular turnbuckles. Much faster and easier to adjust without messing around with bits of thread

I was thinking of running dyneema on some areas my lifelines, I'll use regular pelican hooks. Easily adjustable minimum messing about.

Lashings are cheaper and lighter and don't ever crevice corrode, gall, or bind. The whole system (on my boat) requires only one clevis pin per shroud. And it looks better. The question is why are people still buying turnbuckles when lashings exist to make our lives better?

[flyingnut40]

Thanks for the input Ben. what size of bow shackle would have a favorable radius for the rope? I expect the chainplate hole to be 7/16" or maybe even 1/2" TBD.

I would feel better if I could eliminate the dogbone to simplify the rig.

I did a closer inspection of the Suncor SS thimbles and it seems the cross section is just under .2 sq " and SS 316 has a tensile strength of 80,000 lbs, so

.2 x 80,000= 16,000 x2 legs of the thimbal.... they should be good for 32,000 lbs. in tension but likely a bit less due to point loading.


I'll check out your site for that info.

[flyingnut40]

Originally Posted by Benz

Lashings are cheaper and lighter and don't ever crevice corrode, gall, or bind. The whole system (on my boat) requires only one clevis pin per shroud. And it looks better. The question is why are people still buying turnbuckles when lashings exist to make our lives better?

Ben,


I like your work, innovative with a twist of frugal.....


You have some really good ideas. However I did not see any pics referencing the shackle at the chainplate to act as a lashing point for the tension line.


A pic would be nice. I would still like a test of the 3/8" thimble breaking in tension.



Since you have a test rig already are you willing/ able to test to destruction? I think I read you can do 10,000 lbs.?


Dennis