Thread: Is that a 12' GIS I see hull down on your horizon

Some brands of dyneema don't have good UV resistance and need a cover. These types like Spectra are much more complex to splice and some are not spliceable.

SS wire is cheap and for a small fee the vendor will make up my stays. However, a swaging tool costs $45 so they are not too expensive either.

I am given a choice of 1/8'' 1 X 19 S/S or 1/8'' 7 X 19 S/S. I'm not sure what the difference is. Also, given the choice of nickel or copper swages, which should I get?

7 by 19 is much more flexible so that is probably what you want. 1 by 19 was typical on larger boats which are rigged and left alone and would be much harder to tame in a situation where you rig and de-rig frequently.

Originally Posted by MiddleAgesMan

7 by 19 is much more flexible so that is probably what you want. 1 by 19 was typical on larger boats which are rigged and left alone and would be much harder to tame in a situation where you rig and de-rig frequently.

Ok, sounds good, thanks. I've heard that ss wire rigging has a working life of around 10 years, and even if the wire looks in good condition, the swage's bond to the wire deteriorates due to bimetallic reaction and this is invisible to the eye, so best to change them. I could not believe how I missed all the broken strands before. It could be that coiling the wire made the strands jump out and become easier to see.

Originally Posted by Joost

Back to spectra 12 strand, 3mm (which is available through Duckworks)?

Should work fine as long as the standing rigging is not in the sun for longer periods of time (does anyone know the impact of UV and the required avarage replacement intervals for spectra?).

Joost

Hi Joost

The problem with ordinary 3mm SK75 for shrouds is that there is way too much stretch for this purpose. On my Moth I have been replacing ss wire with Dyneema in a few places, ie. vang primary strop, foot of the mast loop that holds control line blocks and a wire traveler for the outhaul at the end of the boom. I used 3mm SK75 Dyneema for the outhaul traveller which is tensioned with a 4cm eyebolt and nut. The traveller is about 40cm long. Once installed, I tensioned the traveler so tightly that my boom became a musical instrument. When I rigged the boat yesterday and applied lots of tension on the vang, it kept stretching so much it became sloppy. I ended up winding the traveler up to its max and you can see in the pic just how much play is left. This actually suits me now as I need this much "give" to ensure the block remains clear of the boom at the end of its travel when the outhaul is maxed, as is the case here. But it just goes to show that whilst this stuff is strong, there is still some stretch to deal with. (By the way, I've replaced that 4mm yellow spectra outhaul line with 2mm Spectraspeed. Huge friction savings)

IMG_0974.jpg

Originally Posted by woodeneye

Some brands of dyneema don't have good UV resistance and need a cover. These types like Spectra are much more complex to splice and some are not spliceable.

SS wire is cheap and for a small fee the vendor will make up my stays. However, a swaging tool costs $45 so they are not too expensive either.

I am given a choice of 1/8'' 1 X 19 S/S or 1/8'' 7 X 19 S/S. I'm not sure what the difference is. Also, given the choice of nickel or copper swages, which should I get?

Sorry, but that info doesn't seem to match up with what info is available here (USA)

(A) Amsteel Blue (made by Samson from Dyneema fiber) is in fact UV resistant
(B) it is dead simple and fast to splice. Samson provides "all you need to know" about splicing and rigging with Amsteel.
(C) costs much less that equiv SS wire
(D) as MIK suggested it's so light that Int'l shipping might still be feasible -- if you do order Int'l make sure to tell them NOT to ship on a spool, the spool weighs way more than the line on it

What SS wire price exactly is "cheap" compared to Dyneema?

For reference - in the USA, Defender Industries (Discount Marine and Boat Supplies - Inflatable Sales - Defender) - demonstrates that the Amsteel-Blue (made by Samson uses Dyneema fiber) size-for-size is both stronger and much less expensive than SS wire.

Defender.com Search Results: amsteel blue

1/8" SS 7x9 wire is $1.09/ft (break str 1,760 lbs)
1/8" Amsteel/Dyneema is $0.45/ft (ave tensile str 2,500 lbs)

3/16" SS 7x9 wire is $1.69/ft (break str 3,700 lbs)
3/16" Amsteel/Dyneema is $0.90/ft (ave strength 5,400 lbs)

1/4" SS 7x9 wire is $2.39/ft (break str 6,400 lbs)
1/4" Amsteel/Dyneema is $1.40 (ave strength 8,400 lbs)

Notes:
(1) Defender is generally VERY price competitive in the USA - but I have also bought (thru eBay) 1/4 Amsteer-Plus at less than $0.60 per foot
(2) They do give volume discounts (I bought 1/4" Amsteel from Defender for $0.67/ft)
(3) Easier to rig/splice by far - no swaging

Cheers.

I was referring to stretch as opposed to strength. There is no doubting the strength of SK75 but its the stretch that's unacceptable in performance dinghies where a mast coming down will all but write off a hull. At the least it's unacceptable for settings to change while racing.

I am not convinced by the arguments in favour of dyneema stays. However, Dynex Dux looks to be the goods, but only for bigger boats. The sizes unfortunately are all geared for big boats, not dinghies, which is what we're discussing here for the S12.

SS wire is very cheap in Oz. I paid $1.95/m, which is roughly half the price of SK75.

Yes, splicing dyneema is dead easy, but so is swaging. I hired a swaging tool today for $15, so for $45 I made a set of stays that would cost me $100 in creepy dyneema.

From reading the blogs and forums, Dyneema has been tried unsuccessfully by International Moths which are at the forefront of change and technology amongst the dinghy classes. They use either SS wire or carbon rod. A Class cats are the same and are still using SS wire.

Howdy,

The revolutionary advantage I see for the Dux is that you can buy a splicing fid for under 10 bucks and then anyone from Hobart to Howlong can make the rigging at home.

For example I don't have a clue about where to start looking for a swaging tool in the Philippines. Happily I have pinoyboats.org where I can ask the question. But I know what I need, I know what it looks like and how to use it.

But access to the tool is the limiting factor.

That's why I'm pretty keen on the Dynex or variation thereof. It has been prestretched with high load. You do lose some of that with the splicing so there can be significant stretch there.

But the nice thing is the information in the five or six posts above would have taken me weeks or months to track down and be sure of.

Thankyou all for questions and arguments, suggestions and answers. Just super!!!!

Looking forward to more!

I'm putting together a fittings list now. Much easier because Duckworks this week decided to stock Ronstan.

MIK

Originally Posted by Boatmik

Howdy,

The revolutionary advantage I see for the Dux is that you can buy a splicing fid for under 10 bucks and then anyone from Hobart to Howlong can make the rigging at home.

For example I don't have a clue about where to start looking for a swaging tool in the Philippines. Happily I have pinoyboats.org where I can ask the question. But I know what I need, I know what it looks like and how to use it.

But access to the tool is the limiting factor.

That's why I'm pretty keen on the Dynex or variation thereof. It has been prestretched with high load. You do lose some of that with the splicing so there can be significant stretch there.

But the nice thing is the information in the five or six posts above would have taken me weeks or months to track down and be sure of.

Thankyou all for questions and arguments, suggestions and answers. Just super!!!!

Looking forward to more!

I'm putting together a fittings list now. Much easier because Duckworks this week decided to stock Ronstan.

MIK

I take it that you are going with the 5mm Dynex Dux for the S12 stays then?

Hi Bruce,

I'm thinking 3 or 4mm, given that the stainless wire for the NS14 is 2.5mm and that has the compression load of keeping the forestay tight for the jib to set efficiently.

Also found this gigaw from camcleat to add to this collection of new thangs.



Clamcleats - Cleat Information

MIK

Rope standing rigging search continues

Gleistein | Chicago Yacht Rigging Inc.Chicago Yacht Rigging Inc.

Dux equivalent lines - Gear Anarchy - Sailing Anarchy Forums

MIK

I can't find it now but someone on here presented an interesting interpretation of what is being called stretch in these high-tech ropes. He said what actually happens with new rope is the strands have to find their true position. Once set in place stretch is no longer going to happen.

IIRC he provided a formula for pre-setting the fibers. Put it under high load (say, breaking strength divided by 2?) and leave it for a while. When done you have line as capable as wire for use as standing rigging.

Did anyone else see that or did I dream it?

Originally Posted by MiddleAgesMan

I can't find it now but someone on here presented an interesting interpretation of what is being called stretch in these high-tech ropes. He said what actually happens with new rope is the strands have to find their true position. Once set in place stretch is no longer going to happen.

IIRC he provided a formula for pre-setting the fibers. Put it under high load (say, breaking strength divided by 2?) and leave it for a while. When done you have line as capable as wire for use as standing rigging.

Did anyone else see that or did I dream it?

I saw that as well. It could have been Anarchy or a Moth site.

The rule of thumb (MIK loves ROTs ) seems to be to size Dyneema to 1/3 of it's breaking strain and that will give you the equivalent stretch/creep of ss wire. People on the forums with some experience of the various forms of dyneema talk about the stretch occurring in the splices as being a bigger problem than the stretch in the material itself. This settles in boats that stay rigged all the time, but it returns in dinghies that are only rigged for a few hours. I'll admit I am coming around to the idea of Dyneema shrouds for dinghies, but I'm still not 100% convinced that it's the way to go as there really isn't enough information out there on this use of the stuff. I would try it myself, but I'm hesitant to risk the Moth as a mishap will see the mast disappear through both the deck and the bottom.

I think we need to keep things in perspective. The top guys in the development classes don't use dyneema, yet. Breaking strength is not an issue, but it is creep which keeping the top Moth guys from using it as they can't get repeatable settings. The top Moths are using ss wire or carbon rod. Carbon rod has a big downside. It is expensive (about $600 for a Moth) and relatively fragile. It needs to be carefully coiled afterwards and it can shatter in a collision. Not a consideration for our boat!

My thoughts for the S12 are it only has to be practical. The questions become:

• If stretch in the splices is an issue, then there is probably no point in going with an exotic form of dyneema in favour of ordinary SK75.
• Will a teeny weeny bit of stretch be hugely critical on the S12 if the correct mast step design is chosen so that at least the mast won't come crashing down?

As you may know, I recently re-rigged my Moth with 2.4mm SS 7x19 wire. When I enquired about the kind tension required for the rig, I was advised to "take 4 turns of cord around the forestay shackle (ie. 8:1), place a foot on the bow and haul hard until the mast won't rotate by hand without the boom attached." I use 4mm Spectraspeed on the forestay adjuster, and to get this sort of tension in the rig I had to wind the cord around a piece of dowel. Such is the tension, that the free standing mast acquires an S bend! This disappears once the sail and boom are rigged, and the mast acquires it's normal slightly pre-bent shape. The tongue in cheek tension test is to strum the wire, and it should play a D.
Online Tuning Fork

OK, so stay tension can be a bit of fun, but we don't really have to go this far and I think if it twangs and is still twangy at the end of the day, that'll be enough for our purposes.

Originally Posted by Boatmik

Rope standing rigging search continues

Gleistein | Chicago Yacht Rigging Inc.Chicago Yacht Rigging Inc.

Dux equivalent lines - Gear Anarchy - Sailing Anarchy Forums

MIK

There is some really good info in there MIK. I will see what's available locally.

Originally Posted by MiddleAgesMan

I can't find it now but someone on here presented an interesting interpretation of what is being called stretch in these high-tech ropes. He said what actually happens with new rope is the strands have to find their true position. Once set in place stretch is no longer going to happen.

IIRC he provided a formula for pre-setting the fibers. Put it under high load (say, breaking strength divided by 2?) and leave it for a while. When done you have line as capable as wire for use as standing rigging.

Did anyone else see that or did I dream it?

MiddleAgesMan,

I'm the "somebody" - you didn't dream of it. I don't remember exactly what I wrote - but I remember what I did...

One thing that I did, and felt was very helpful was to make up the shrouds with the spices included before I tensioned the shrouds to take out the slack of the unaligned fibers that are part of the manufacturing process.

((Many folks still misunderstand the Amsteel-type woven 12-strand type of line - thinking of them as if they are linear core with cover - which is not true and why so many think there's a lot of what they call "stretch" ))

I size the shrouds based at 20% of breaking strength (as recommended by the manufacturer, Samson - that's their "ROT", and I use it) . It's my personal opinion that if you size the Amsteel/SK75,80,90 lines correctly then you are sizing so that you only get the amount of stretch that you find acceptable.

((There's always stretch, whether synthetic or SS - so you size for it, that's it, there's no 'one is better than the other' just different - it's the low weight, easy to rig, easy to repair, and low cost (especially when you include the associated hardware) attributes that I'm after so I prefer synthetic - of course there are additional benefits like using synthetics to eliminate metal hardware all over the boat. Soft shackles come immediately to mind.))

I remove the mechanical "set" by tensioning the line to approx twice the righting moment that the shrouds will be subjected to - because that's what makes sense to me - nothing to do with the breaking strength ( I may have may have misstated that originally, but no matter now). On my rotating mast boats shrouds only actually get loaded up to the equivalent of the tension that produces the max righting moment - which is surprisingly low when you actually calculate it.

I use a simple ratcheting comealong - something that is easy to borrow or cheap to buy (Amazon 10ton pulling capacity for $50 bucks - more than adequate for the boats I work on).

Between fixed objects (telephone poles work nicely - if you're careful ) I use the come along to add tension. It takes a while -- since the first time you add tension the line starts to stretch (as the fibers gradually begin to get into alignment) so you need to let it work then add tension again and again until it stops stretching at that same load.

Hope that is reasonably clear.

Just do it, it is very hard to screw it up. And I don't worry it to death about using all the special splices either - I splice exactly as Samsom suggests (they did the testing and that's okay for me).

The one thing I do (on rotating masts) - for the thimbles at the hounds - is to go oversize them so that the line is buried deeper in the channel. This (my opinion) helps protect the line from chafe of banging against any other shackles/shrouds at the hounds.

Cheers,
TomH