DIY Standing Rigging

[Stumble]

While I am a huge fan of dyneema rigging, the expected life of the rope is only 8 years. The hardware however depend on the material. If aluminium then almost forever, if stainless then it depends on corrosion.

[mstrebe]

Really? My rigger was more optimistic. Unfortunately it hasn't been around long enough to really know. It doesn't corrode, but it does UV degrade. However the surface layer blocks further degradation (like the oxide layer on stainless). So according to him, you buy it oversized by 1mm, and that becomes the degraded surface layer.

[VinnyVincent]

mstrebe- the idea of using synthetic rope is intriguing since I am still in the planning/learning phase.

How did the rigger connect the rope to your boat and mast? Do you have any pictures?

[mstrebe]

Originally Posted by VinnyVincent

mstrebe- the idea of using synthetic rope is intriguing since I am still in the planning/learning phase.

How did the rigger connect the rope to your boat and mast? Do you have any pictures?

On this particular boat, which is fractionally rigged and has a rotating mast, the stays are connected to a hound and a large shackle, so we just used sailmaker's thimbles and spliced the dyneema to form a loop around it. Same thing on both ends. You have to protect the dyneema at the spreaders from chaffing, so we wrapped them with tape before clamping them down. At the chainplates, they're just connected to the stock stay adjusters with an appropriate shackle.

If you learn how to do a proper splice over a thimble, you can do this yourself. The only hard part is you have to pull the dyneema out (stretch it) using a press that can create the correct force, which in my case was 4,000 pounds. This pre-stresses the dyneema and makes it inelastic. It will then slowly creep tighter over time as the stays work, and you can release that extra pressure at your turnbuckles until they're out of room, and which time you need to re-pull your stays.

Basically they age opposite of stainless--instead of getting looser over time, they get tighter. Unlike stainless, you can make them new again by pulling them out with no loss of strength.

So in sum, you just splice them around a sailmaker's thimble at each end, and then use shackles to rig that.

You _can_ actually just knot them around the thimble using a figure-8 loop knot that is finished with half-hitches and a stopper. If that knot survives being pulled out with a press, it will jam and provide 100% of the breaking strength of the rope. If it comes out when you pull out the dyneema, well, you did it wrong. In any case, because you have to pull the rope out, you can know in advance whether a simple knot will hold.

You must use a thimble for the bend however, because using the rope alone will reduce its breaking strength by something like 40% because all the rope fibers are not equally loaded at the bend.

[VinnyVincent]

Originally Posted by mstrebe

On this particular boat, which is fractionally rigged and has a rotating mast, the stays are connected to a hound and a large shackle, so we just used sailmaker's thimbles and spliced the dyneema to form a loop around it. Same thing on both ends. You have to protect the dyneema at the spreaders from chaffing, so we wrapped them with tape before clamping them down. At the chainplates, they're just connected to the stock stay adjusters with an appropriate shackle.

If you learn how to do a proper splice over a thimble, you can do this yourself. The only hard part is you have to pull the dyneema out (stretch it) using a press that can create the correct force, which in my case was 4,000 pounds. This pre-stresses the dyneema and makes it inelastic. It will then slowly creep tighter over time as the stays work, and you can release that extra pressure at your turnbuckles until they're out of room, and which time you need to re-pull your stays.

Hmmm, very interesting. It seems like this would be much cheaper and more DIY friendly, unless I am missing something? My current steel cables are mostly 3/16" thick. If I were to buy 3/16" Dyneema to replace them, which actually seems a bit overkill, from what I am seeing on average it's about 4 times cheaper for the Dyneema AND you can save on the fittings by not having to use swage/stalock fittings? Again, am I missing something here? Why aren't more people making this switch when it comes time to replace?

[mstrebe]

You aren't missing anything. In fact a lot of people are moving to synthetic when they replace.

Sailors are a cautious lot, especially when it comes to safety of life equipment which standing rigging is.

When you do this, use dyneema dux, which is pre heat treated and stretched. It's specifically designed as a steel wire replacement. Look up the breaking strength for your existing rigging, and find the size of dyneema dux that matches or slightly exceeds that rating.

Then add 1mm. This is critical to ensure that UV degradation over the life of the rigging doesn't go below your load rating requirements. The surface of dyneema will degrade because of UV, but then protect the layers below. So this extra mm is a sacrificial.

Dyneema Dux can be pretty stiff and hard to work or knot at larger sizes. Practice splicing over some thimbles and pulling those ropes with a truck and a tree until you can make splices that don't pull out when the rope breaks. As long as the rope breaks before the splice, you're doing it right.

Good luck!


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[Captain Obvious]

I replaced all my stays except for the forestay (roller fuller) with dynex Dux. Stronger than steel. Lovely to work with, great on the hands and my rigging feels rock solid. I did my lifelines too as it is just so nice to touch or lean against. Much lighter too so less weight up high.

You need to use the modified Brummel splice. It self locks and cannot undo.


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[Dave852]

Quote "

Basically they age opposite of stainless--instead of getting looser over time, they get tighter. Unlike stainless, you can make them new again by pulling them out with no loss of strength."

Wow, your understanding of creep is 180 degrees from mine:-)


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[GordMay]

➥ http://www.colligomarine.com/docs/misc/DynexDuxFAQ.pdf

➥ Dynex Dux fiber rigging after 6,000 sea miles - Sail Magazine

[mstrebe]

Originally Posted by Dave852

Quote "

Basically they age opposite of stainless--instead of getting looser over time, they get tighter. Unlike stainless, you can make them new again by pulling them out with no loss of strength."

Wow, your understanding of creep is 180 degrees from mine:-)


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Yeah, I found it hard to believe as well, but this is according to my rigger for stays that have been pulled out to pre-stretch them. If you don't pull out the dyneema dux after splicing the ends, it will creep rapidly and longer. The pre-pull to max load is what causes the reverse creep.

Mostly they just don't creep at all. Mine are a year in with no change in tension. Same size Dux vs. 1x19 wire is 4X stronger.


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[VinnyVincent]

Does anyone else sell Dux or is it exclusive to colligo marine? That seems to be the only place I can find it for sale. Their prices for the rope are about 6X higher than the regular Dyneema I was looking at yesterday.
Problem is, from what I can tell, replacing my 3/16 stainless wire I would need 7mm Dux. That's 4+ dollars a foot compared to the stainless 3/16" wire I found online for .98 a foot.
Add in their special dead eye connectors and you are looking at a significantly more expensive setup than the plain jane 1X19 SS.

From what I can tell, it seems like one of the most expensive parts when going the 1X19SS route is the swage/stalock fittings.
Is there anyway around using these?
Why couldn't I just use swaged eye terminals on both ends, like this:



I already have the tools at work to make these and I can borrow them. Seems like you could attach them to the turnbuckle with a shackle and call it a day?

[Dave852]

Originally Posted by mstrebe

Yeah, I found it hard to believe as well, but this is according to my rigger for stays that have been pulled out to pre-stretch them. If you don't pull out the dyneema dux after splicing the ends, it will creep rapidly and longer. The pre-pull to max load is what causes the reverse creep.

Mostly they just don't creep at all. Mine are a year in with no change in tension. Same size Dux vs. 1x19 wire is 4X stronger.


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You are confusing constructional elongation and splice slippage with creep. Creep occurs from long-term static loading, in other words when you tighten your turnbuckles and leave them tight. The pre-stretch you are referring to tightens the splices and general construction of the weave. But from there you will add creep over time, just a bit but it will be there. So you start with the turnbuckles rather open and will tighten them over time. Besides uv concerns creep is the main reason you oversize dyneema, to lesson the creep. You wind up with a much higher breaking strength than steel because you are engineering to minimize creep, not match the strength.


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[Stumble]

Originally Posted by VinnyVincent

Does anyone else sell Dux or is it exclusive to colligo marine? That seems to be the only place I can find it for sale. Their prices for the rope are about 6X higher than the regular Dyneema I was looking at yesterday.
Problem is, from what I can tell, replacing my 3/16 stainless wire I would need 7mm Dux. That's 4+ dollars a foot compared to the stainless 3/16" wire I found online for .98 a foot.
Add in their special dead eye connectors and you are looking at a significantly more expensive setup than the plain jane 1X19 SS.

From what I can tell, it seems like one of the most expensive parts when going the 1X19SS route is the swage/stalock fittings.
Is there anyway around using these?
Why couldn't I just use swaged eye terminals on both ends, like this:



I already have the tools at work to make these and I can borrow them. Seems like you could attach them to the turnbuckle with a shackle and call it a day?

A few things...
1) regular dyneema isn't suitable for standing rigging. You have to use Dux or the amount of creep you will get is going to be crazy. It's more expensive, but there are plenty of places that sell it.

2) Colligio fittings are the gold standard, my boat uses eye splices attached to turnbuckles instead. A heck of a lot cheaper. What you will need depends on your rig, but call John and ask for a quote. It will likely be in the same range as wire the first time, substantially cheaper at the replacement interval where the fittings are reusable.

3) nico press fittings aren't made that fit stainless wire. You would also need to switch to galvanized. It's an option, but not a good one in balance.

[poiu]

Originally Posted by Stumble

A few things...
1) regular dyneema isn't suitable for standing rigging. You have to use Dux or the amount of creep you will get is going to be crazy. It's more expensive, but there are plenty of places that sell it.

As I understand it Dux is a pre-tensioned, heat set dyneema using grade 75. That treatment removes the construction stretch so there is only creep and fibre stretch to deal with. Those elements are much smaller then the constructional stretch so Dux is hugely easier to fit and tension.

There is a new Dyneema fibre: Dyneema Max, which has a vastly improved fibre creep performance. I don't know why that isn't used instead as I expect with long term use that the fibre creep with Dux should be a problem, especially in permanently fixed highly tensioned rigs. it may be feasible to build one's own pre stretch heat set rig and use Dyneema Max if a Dux version can't be bought.

[seandepagnier]

I recommend using dyneema as that's what I used. Otherwise consider galvanized. Don't use stainless as it's expensive and can fail without warning (it's not the right material for standing rigging)

I used bronze chainplates I made from bronze bar, and turnbuckles (I got half inch bronze ones for $10 each)

I got the dux 7mm for $1.80 per ft but this was already more than 4 years ago.

I think if you cannot find the dux, it would be possible to get the regular stuff in a larger diameter and stretch it yourself. The other option would be to simply use it as is, and use deadeyes and remember to keep tightening it as it stretches. Eventually it will stop.

If you cover the dynemma from the sun it should last a very long time, but without this it probably lasts already 20 years because although the outside gets weaker, it protects the inside and it's a lot stronger than it needs to be.