Calculating Dyneema for Standing Rigging

[flyingnut40]

Originally Posted by SailFastTri

3000 # is not enough to get rid of constructional stretch, and you would need to sustain your load over time. You can’t cut corners and get the same results as the pros.

With the exception of a few (like colligo marine) most DIY types are using back yard physics. I'm working on something in the middle. I like to think of it as
"Trust but VERIFY" I don't know if I'll build a full test rig but if I got a deal on a really big I Beam..... I might.....

[smj]

Originally Posted by unbusted67

Colligo, Colligo, Colligo. I hear about these guys on every forum everywhere. Is it maybe, just maybe possible that they have cornered the market on synthetic standing rigging through a very aggressive marketing campaign around Dynex Dux and that maybe there are other options? New England Ropes has a couple of heat set options HST78 HST90...I don't doubt that they are good but are they twice or even three times the price of other options good? Must we also buy their extremely expensive hardware?!?! Just playing devils advocate here and kind of joking...but also not.

Google Kraken Structures, another option.

[Benz]

Originally Posted by smj

Google Kraken Structures, another option.

Googled it, but Kraken doesn't seem to make any hardware--looks like he's using closed SS thimbles and putting lashings on them like they were deadeyes. Nothing wrong with that, if you can deal with the legs trying to ride up on each other, but it can get awkward.
There was an outfit called Precourt some years back making deadeyes, but their design was poor and they seem to have disappeared. For now it looks like Colligo is the only player making actual functional deadeyes in aluminum.

[smj]

Originally Posted by Benz

Googled it, but Kraken doesn't seem to make any hardware--looks like he's using closed SS thimbles and putting lashings on them like they were deadeyes. Nothing wrong with that, if you can deal with the legs trying to ride up on each other, but it can get awkward.

There was an outfit called Precourt some years back making deadeyes, but their design was poor and they seem to have disappeared. For now it looks like Colligo is the only player making actual functional deadeyes in aluminum.

Give him a call, if your interested in dyneema rigging it will be worth your time in my opinion.

[unbusted67]

Originally Posted by flyingnut40

I don't consider 8+ years of this stuff being on cruising boats to be new....

Here is a start Ben....

https://www.ebay.ca/itm/5-13mm-Hampi...Kl3MW1P7_hTkTw

or here

https://jimmygreen.com

I found endura 12 SK75 on sale at;

https://rwrope.com/

I bought enough to do a 36' boat for about $900

I'm not just blindly diving off the high board with this stuff.... but I will cut thru the mystery that keeps prices high.... stay tuned.

Thanks, I mean still, 300 feet of this stuff @8mm is about $950 (I estimate needing 360 feet), plus thimbles, plus small stuff for lashing and we are looking at comparable prices for swage fittings on SS. Not complaining...just seeing the reality that it's not really cheaper that SS. Let's not forget shipping because it doesn't seem like I can find any of this in the states retail.

[Benz]

Originally Posted by smj

Give him a call, if your interested in dyneema rigging it will be worth your time in my opinion.

Ah--I'm not shopping for rigging. I was just curious whether anyone other than Colligo is making deadeyes. Someone will eventually, and then prices will have to come down. Or at least stay the same.

[Benz]

Originally Posted by flyingnut40

And yet I have read that once stretched to its working load, regular Dyneema will stabilize and then experience even less creep than DUX. My understanding is if you allow for this and pre-stretch your stays you can reduce the need for re-splicing.

This assumes that you are using dead-eyes, NOT turnbuckles. If you want to use turnbuckles, then DUX or NER STS is the only way to go.

Having said that, there is at least one cruiser out there that started with turnbuckles and after a year decided to eliminate them in favor of dead-eyes.... I forget the poster, but I could find it if you need the actual name.
If you are building dead-eyes (you can buy them from Kraken Structures) the HD closed Suncor thimbles are under $3 each from Fisheries Supply in 3/8".
I am planning a re-rig of my next boat in Dyneema, not DUX because of cost and as such I am removing the stretch of my stays in a very controlled manner.
I have purchased a 10,000 lb. load cell and display that I can both test a new dead-eye idea AND pre-stretch my stays. I also purchased a chain come along that will do up to 3000 lbs. to do the pre-streching.

Not wanting to hi-jack your thread.....

If anyone wishes to keep up with this project over the next 6-8 months, let me know and I will start a thread dedicated to DIY rigging on a tight budget.
Dennis

Can you cite where you read this? AFAIK, DUX (which is SK 75), is the most stable of the Dyneema family once the splice is pulled in tight. SK 78 will always have a little bounce back ( I do a lot of pulling on a 10-ton test bench), SK 78 MAX (prestretched) will still bounce more than DUX in my experience--the only thing that comes close is SK 99. Given the choice (where price was no object) I'd still choose DUX over any other dyneema product, though I'm watching that new DM20 with interest.

[Benz]

Originally Posted by unbusted67

Thanks, I mean still, 300 feet of this stuff @8mm is about $950 (I estimate needing 360 feet), plus thimbles, plus small stuff for lashing and we are looking at comparable prices for swage fittings on SS. Not complaining...just seeing the reality that it's not really cheaper that SS. Let's not forget shipping because it doesn't seem like I can find any of this in the states retail.

If the price is comparable, then the advantages of synthetic rigging are still there to outweigh (heh!) the evils of SS.
RigPro in Portsmouth, RI carries everything that Marlow sells, which includes their full line of pre-stretched Dyneemas.

[flyingnut40]

Originally Posted by Benz

If the price is comparable, then the advantages of synthetic rigging are still there to outweigh (heh!) the evils of SS.
RigPro in Portsmouth, RI carries everything that Marlow sells, which includes their full line of pre-stretched Dyneemas.

I dont expect to beat the price of SS...... but improve on the $4-5000 you could spend at the PRO shop.....

Colligo makes some beautiful aluminum thimbles with the individual rope holes etc and if using turnbuckles they would be very nice but not at $70 a Piece!!!

I need to go back to their website and see their dead eyes again...... I just remember that at those prices I would have to go with SS and risk the rusting, cracking, fraying and other shortcomings of swegging and/ or mechanical fittings. You just cant get away from fatigue on wire.

The easier inspection and ability to repair yourself anywhere are my priority even it it does cost a bit more than SS.

Off to Colligos website to see those dead eyes......

[flyingnut40]

O.K...… I'm NOT dreaming..... went through pretty much the whole website and NO deadeyes.... lots of other neat stuff.... really cool.... but way above my budget.

If you can find a deadeye.... please share a link...

Colligo is BIG on using turnbuckles WITH their very nice thimbles.

I DID see the lashing thimbles connected DIRECTLY to chain plates WITHOUT toggles which in my mind is ill advised. How can they break THAT rule? Are they thinking that a buzzing wire will fatigue at the swage but a rope will not?

I'm listening for your opinions.....

[carlosproa]

Originally Posted by unbusted67

Hey all,



I'm going to do my standing rigging myself with Dyneema using thimbles and dead eyes. I have a ketch with 1/4" SS on the main and 3/16" on the Mizzen.



Using Colligo's stretch calculator it looks like I should go with 5/16 and 1/4" Dyneema respectively. If I were to replace with stainless I'd be looking at a total of 310 feet of 1/4" SS for the main and 120 of 3/16"SS for the mizzen



1) How do I calculate length of dyneema? It looks like I should anticipate appx 30" for dead eyes and lashings per stay. Have others found this to be accurate? What about calculating for splicing and creep? Is adding 20% to the stay lengths adequate to account for bury in the brummel splices?



2) what size (gage?) lashing material should I use for lashing dead eyes? 1/8"?

Go to YouTube and see Sailing Zíngaro as he did a very in-depth documentation on all kind of Dynema projects. He is in this group but not sure how active he is

[flyingnut40]

Originally Posted by SailFastTri

3000 # is not enough to get rid of constructional stretch, and you would need to sustain your load over time. You can’t cut corners and get the same results as the pros.

According to Colligo here is their schedule for re-stretching lines for removing constructional stretch...…


The re-stretch loads we use are as follows:
Line size / Minimum re-stretch load
7mm & 9mm / 2,000 lbs
11mm / 3,000 lbs
13mm / 4,000 lbs
16mm / 8,000 lbs

Since I wont be using anything bigger than 9mm I think 3000# should be O.K.

[flyingnut40]

O.K. so I have been through the Colligo site from end to end and I think their stuff is beautiful "work of art" stuff.... well engineered and pricey.
If money is no object, by all means pay 2 -3X more than SS for your rig.
That's not the objective I'm working on here.

I'm looking to have better function and reliability than SS at a cost that preserves my cruising kitty resources for other stuff. If I need to replace it in 8-10 yrs. so be it....

I understand that JOB 1 is to keep the rig up!!

I think it's time to start a thread devoted to this so have a look for a new post...…

[flyingnut40]

New related thread...

https://www.cruisersforum.com/forums...04#post3090404

[Benz]

Originally Posted by flyingnut40

O.K...… I'm NOT dreaming..... went through pretty much the whole website and NO deadeyes.... lots of other neat stuff.... really cool.... but way above my budget.

If you can find a deadeye.... please share a link...

Colligo is BIG on using turnbuckles WITH their very nice thimbles.

I DID see the lashing thimbles connected DIRECTLY to chain plates WITHOUT toggles which in my mind is ill advised. How can they break THAT rule? Are they thinking that a buzzing wire will fatigue at the swage but a rope will not?

I'm listening for your opinions.....

Perhaps we are using different terms. Those thimbles with individual rope holes you saw are what I call deadeyes. Colligo calls them something like "line terminators," or "distributors) but they are deadeyes. You don't need a toggle when you have a flexible rope lanyard.
As for $70 apiece being steep, well, look at the price of turnbuckles with toggles and pins. Then look at the price of having some machined for you and anodized. $70 each begins to sound very reasonable, IMO.