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Has the time arrived for synthetic rigging?

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(@Anonymous 13024)
Posts: 4319
Topic starter
 
[#29383]

Hi all,

it looks like synthetic rigging is becoming more and more common in the yachting world. Have the time now arrived for beachcats also to go synthetic?

For our boat I am serious about using synthetic for all stays but keep the diamonds in SS wire.

Earlier it was suggested to keep some SS wire for the sections wrapped around the mast when rotating the mast. Still valid?

I have seen Colligo Marine referenced and SK78Max as one line option. Others?

Anybody with experience or opinions?


 
Posted : September 24, 2012 11:18 am
(@waynemarlow)
Posts: 877
Chief Registered
 

Been there and done that, it has so many advantages that it should be a no brainer, easily spliced, widely available, lighter in both guage and weight, easy on the hands and body when you end up crashing into it and the list goes on.

The one downside is that I could not ever halt the very slight creep over time. Its very little but never the less I had to adjust the rigging every time I used the boat and by consequence just couldn't get the boat settled to one constant rig setting.

Sadly I gave up and now have gone back to steel rigging.


 
Posted : September 24, 2012 11:59 am
(@Anonymous 13024)
Posts: 4319
Topic starter
 

What kind of fibers did you use and what size?


 
Posted : September 24, 2012 12:01 pm
(@waynemarlow)
Posts: 877
Chief Registered
 

At the time ( which was a about 4 years ago ) the Marlow D12 was about the only real high strength available, but in theory absoluteley fitted the brief. I used 4mm all around but in hindsight I should have gone down a size to 3mm which may have stopped some of the creep. I notice to that you can get this D12 now in pre streteched form so maybe it is worth a go.

D12 is one of those ropes I find totally indespensible, you can do almost everything on a boat with it, from soft shackles to main sheet ( in the cascade system ) to the spinny retrieve where it is soft enough that it never seems to burn the spinny no matter how hard you try.


 
Posted : September 24, 2012 12:12 pm
(@Anonymous 13024)
Posts: 4319
Topic starter
 

Thanks!

I heard referenced to size for creep and not strength. So 5mm Dux75Max (that is pre-stretched Dux75) was suggested for a beachcat. Does that make sense in your opinion?


 
Posted : September 24, 2012 12:15 pm
(@waynemarlow)
Posts: 877
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5mm really touches on being aerodynamically brick like. To be honest why change from steel, its very well proven, you could use 2.5mm if you want, widely available at relatively modest cost, easy to rig and to be honest weight shouldn't be a problem ?

I wasted a good few weeks titavating about to simply get easily adjustiable rigs, in hindsight they were very wasted weeks.


 
Posted : September 24, 2012 1:10 pm
(@Anonymous 13024)
Posts: 4319
Topic starter
 

Steel is heavy exactly where I dont want weight. I would also like to make the stays myself.
On the Tornado I belive we had 4mm dyform wire. Not far from 5mm..

How big is the drag vs reduced weight, and how to quantify the advantage/disadvantage for each option? I believe the added leverage in the rig when sailing in any kind of waves reduces the propelling force far more than the drag subtracts from the propelling force. But I am unable to quantify this.

Anybody?


 
Posted : September 24, 2012 1:17 pm
(@Anonymous 38725)
Posts: 5859
 

My main concern would be about the synthetic stuff being cut or frayed and then breaking while I'm out racing. My steel stay wires are not that heavy in the first place and I like not having to worry about stretch or breakage, especially when I leave the boat with the mast up for a month or more.


 
Posted : September 25, 2012 11:22 am
(@Anonymous 13024)
Posts: 4319
Topic starter
 

Would synthetic wires break more often on beachcats compared to larger multis like Farrier trimarans, or 60 foot tris?
I dont think so <img src="<>/smile.gif" alt="smile" title="smile" height="15" width="15" />


 
Posted : September 25, 2012 11:57 am
(@Anonymous 38725)
Posts: 5859
 

My nightmare is when you leave your beach cat alone overnight and some clown with a knife or a cigarette lighter comes by...

The bigger boats are usually kept at more secure locations, and they save more weight up high as their wires weigh quite a bit more. I think my steel stay are thinner than 3mm, so the synthetic stuff would add drag up high, right? Is that better or worse than a few oz. of weight?


 
Posted : September 25, 2012 12:02 pm
(@Anonymous 13024)
Posts: 4319
Topic starter
 

Would that guy take the same knife or lighter to the trampoline or whatever? I dont know. Around my area boats are most often left alone.

I am willing to trade that risk against some performance <img src="<>/smile.gif" alt="smile" title="smile" height="15" width="15" />


 
Posted : September 25, 2012 12:09 pm
(@Anonymous 38725)
Posts: 5859
 

You live in a better place, no doubt! Here in Florida you can't leave ANYTHING outside over night, or you risk losing it if it's small enough to be hauled off, or damaged, if it's in a public spot.

There have been many guys who have found cigarette burns on their tramps the next morning at a public beach regatta.


 
Posted : September 25, 2012 12:42 pm
(@Anonymous 13024)
Posts: 4319
Topic starter
 

I leave my boat at the club and dont worry about it. No fences at the club, mainroad to the town passes 100 meters from the lot. Pedestrian road passes almost through the club. Except from kids who wants to jump on the

trampoline

and one incident where we either lost a locking pin or somebody removed it. There have been no man-made issues with our boats there at least.

Resale value for a stolen cat in the domestic market would be nil.

Perhaps you should relocate to this place and begin flying for SAS <img src="<>/wink.gif" alt="wink" title="wink" height="15" width="15" />

Other concerns or thoughts about synthetic rigging? How about the drag issue Wayne mentioned with 5mm stays instead of 2.5/3mm?


 
Posted : September 25, 2012 1:02 pm
macca
(@macca)
Posts: 981
Member
 

you should not forget the dynamic elasticity difference with dyneema and wire. You will notice that the boat feels softer if you change to dyneema.

As a good example, the M2 class changed from unidirectional wound aramid side stays to PBO and within one regatta they noticed that the chainplates were pulling out of the deck on almost all boats... the PBO was transfering the loads much more directly and hence the issues...


 
Posted : September 26, 2012 10:30 am
pgp
 pgp
(@pgp48)
Posts: 4470
Member
 

I'd be opposed to changing class rules. Change just creates dissent and ill-will.


 
Posted : September 26, 2012 10:50 am
(@Anonymous 13024)
Posts: 4319
Topic starter
 

Wait a sec Macca, I thought PBO was also a fiber, but much less elastic than aramid?

What would you recommend as a budget solution for fiber rigging on an F16 to be sailed by a 102kg crew (102kg + equipment/clothes)?

Aaaaand.... What are you currently filling your time with? Still sailing? Boating business or something completly different?


 
Posted : September 26, 2012 10:52 am
(@Anonymous 13024)
Posts: 4319
Topic starter
 
Originally Posted by pgp
I'd be opposed to changing class rules. Change just creates dissent and ill-will.

Did you post to the wrong thread Pete? I see no changes to class rules to implement fiber based rigging?


 
Posted : September 26, 2012 10:53 am
pgp
 pgp
(@pgp48)
Posts: 4470
Member
 

No, all these discussions usually lead to talk of rules changes. Sorry, guess I jumped the gun.

I'm satisfied with my equipment as it is.


 
Posted : September 26, 2012 11:13 am
macca
(@macca)
Posts: 981
Member
 
Originally Posted by Rolf_Nilsen
Wait a sec Macca, I thought PBO was also a fiber, but much less elastic than aramid?

What would you recommend as a budget solution for fiber rigging on an F16 to be sailed by a 102kg crew (102kg + equipment/clothes)?

Aaaaand.... What are you currently filling your time with? Still sailing? Boating business or something completly different?

Aramid is much less elastic than Dyneema (although a unidirectional dyneema SK90 is pretty good these days) but PBO is really great stuff and has a very small amount of elasticity and it is a noticeable difference. We are using solid carbon on a new project now and it is a huge step up from PBO in stiffness and elasticity so we expect to see a similar gain.

For a beach cat like your F16 I think you will struggle to find anything off the shelf that is better than wire for the same diameter, but you should have a look at easy rigging if you are serious about it. Sure its more expensive than wire or rope, but its a lot better.

As for my current project.... you will all see soon enough <img src="<>/smile.gif" alt="smile" title="smile" height="15" width="15" /> it pretty special and will certainly make the news.


 
Posted : September 26, 2012 12:55 pm
(@Anonymous 13024)
Posts: 4319
Topic starter
 

I dont mind going up in diameter and trade drag for weight reduction. I'll see if I can find uni SK90.. Starting to unravel uni carbon cloth and glue on terminals myself would be a bit too exciting I think, even if fun! What is the UV rating for carbon fibers in the sun..

Easy Rigging is noted..

Looking forward to see the announcement of the project!


 
Posted : September 26, 2012 1:04 pm
macca
(@macca)
Posts: 981
Member
 

its possible to make your own carbon stays, you need to pass the uni fibres inside a length of heat shrink tube and wind them around a thimble at each end, then set the thimble ends in resin and shrink tube to keep it all together.

takes a lot of patience and mucking around... in the end if you value your time then you are much better to buy from someone like easy rigging


 
Posted : September 26, 2012 2:13 pm
(@Anonymous 13024)
Posts: 4319
Topic starter
 

What about breakage where the stays are rolled around the mast when tacking and jibing? Are there special techniques to handle this or was the issue overrated when

plastic

rigging was new?

I am actually tempted to try to make carbon stays.. If my more conservative building partner is up to it <img src="<>/laugh.gif" alt="laugh" title="laugh" height="15" width="15" />


 
Posted : September 26, 2012 3:08 pm
macca
(@macca)
Posts: 981
Member
 

as long as you make sure that the resin hard area is limited to the thimble only (you cant have the unsupported cable stiff from resin) then its fine


 
Posted : September 26, 2012 4:23 pm
(@Anonymous 13024)
Posts: 4319
Topic starter
 

Hoy Macca,

do you know how they handle carbon diamond wires on masts? What is done on the spreaders to avoid chafe and breakage there?

I have to think a little about how to set up the timbles unless you have some good links. So far a mental exercise but very interesting stuff!

At least now that I hear carbon fibers slowly being introduced as rigging I am certain that synthetic stays is viable and also the way to go for the future <img src="<>/smile.gif" alt="smile" title="smile" height="15" width="15" />


 
Posted : September 27, 2012 3:33 am
(@waynemarlow)
Posts: 877
Chief Registered
 

Any piccies out there of these carbon stays ?


 
Posted : September 28, 2012 6:28 am
macca
(@macca)
Posts: 981
Member
 

The stays are fine around spreaders, but you need to make a nice piece of carbon or stainless to ensure its a larger surface than the normal wire mounting.

i have been looking for pics, but none with me.

There is another option from maffioli that could be good. its called ultrawire and can be supplied in 3, 3.5 and 4mm sizes in either SK90 and Zylon (PBO) this is a pretty good solution for you guys.


 
Posted : September 28, 2012 7:23 am
Smiths_Cat
(@Smithscat)
Posts: 569
Chief Registered
 

I absolutely agree with Wayne. In short Dyneema isn't right for standing rigging. With Vectran you could solve the problem of creep (pre stretching Dyneema is only marketing blabla). But compared to steel of similar diameter I don't like the softness, although I could never measure a difference in speed (I have no jib). Hence this is very to your like. With a jib I would always go with the stiffest material.
Never used PBO, Carbon or Aramid on my boat. None of them like UV and water, hence need sophisticated protection and one would lose the diameter advantage on small boats.

On small cats, rigging drag is more important than weight (cross-section area depends on diameter in square and drives strength and weight, drag depends on diameter only).
The performance difference to 2.5mm steel (for uni) is more in your mind than on the water for a small cat anyway.

Since three or four years I use synthetic ropes (dyneema) to connect the wires to the mast fitting, so that the steel wire never touches the carbon mast. Makes the boat silent as well.
Never had any failure. The boat is exposed the full season to UV and weather.

Cheers,

Klaus


 
Posted : September 28, 2012 5:25 pm
(@Anonymous 13024)
Posts: 4319
Topic starter
 

Hi Klaus,

what I have observed is that our rigs move about a lot as we sail trough waves. The thinking is to reduce weight aloft to get less inertia from the rig movements and thus get more speed.
The opposite value is increased drag if synthetic materials have a bigger diameter than metal wire.
Are you able to quantify this in a meaningful way? How much will total drag increase if going from 3mm to 5mm stays. The

reduced inertia

factor can be calculated, but how to compare this... I have no clue but I have a feeling <img src="<>/smile.gif" alt="smile" title="smile" height="15" width="15" />

Additional advantage could be easier righting for lightweight crews and a small degree of better righting movement.

I dont see why the jib makes a difference in metal vs synthetic rigging? Unless the rigging is really stretching and flexible the forestay will be tightened by the mainsail sheeting loads going upwind.

What is the issue with water and UV on carbon? Is carbon fibers UV degradable? Water degradable? Or are you thinking of the fittings and resins being broken down by UV and galvanic corrosion?


 
Posted : September 29, 2012 3:00 am
Smiths_Cat
(@Smithscat)
Posts: 569
Chief Registered
 

Hi Rolf,

a moving rigg isn't bad. Actually it has improved aerodynamics. In many dinghi classes

pumping

(e.g. periodical change of the sail inflow conditions or sail angle) if limited or forbidden, because people feel that their seems to be an advantage by doing so.
Hovever if the motion causes excessive hull drag due to splash or nose diving, it can't be good. There are many possibilities to do cure the problem: Hull shape, T-foil rudders and reducing inertia.
Reducing inertia is always good, but unfortunately the standing rigging is only small part of the mast-sail system and this is only a part of the whole boat inertia. Hence the gain by playing with lighter standing rigging is small.
Hull shape has significantly improved in the last years. For example my Javelin sails far smoother in waves than the 4 ft longer Tornado. I would expect similar or even better wave-going behaviour for the F16, becase of the lower mast and lower inertia.
The most efficient way would be a T-foil(ed) rudder. It will not only damp the pitching motion, but transfering the energy from pitching in thrust (negative drag). However in calm water you would have drag penalty.

The advantage of essier rigging is on F16 size boat fairly low. I didn't feel any difference.

The jib makes a difference: From your comment I see that we agree that a sagging jib is not good (especially upwind). If you don't have a too flexible mast the main sheet will keep the forestay tight. But when you react to a puff by opening the main your jib would start to sagg in exactly that situation where you want a flat jib.

Every rope from organic (e.g. plastic, anorganic = metal) suffers from UV and water. The question is how fast.
BTW I know of carbon fiber only used with resin, hence a rod and not a rope. So the UV and water resistance of the resin would be important. It should have some addtitional protection (e.g. PU or wax).

I guess some googleing would reveal you, that
Dyneema is good againbst UV and water (I replace the unbraided dyneema ropes on my boat only once a year), Vectran is used for tugging dipping sonars and on space-exploring vehicles, hence I would think of good resistance as well. Aramid and PBO are on the low end of the table.
I can tell you that Aramid (Kevlar) has so poor water resitance that we don't use it in our business (even not with epoxy resin and PU coating), but an aircraft has a different utilisation of course.

Regarding the drag increase due to diameter, I think I made some calculations already on this forum.
Btw is 5mm a bit much for a single hander?

Cheers,

Klaus


 
Posted : September 30, 2012 2:27 pm
(@Anonymous 13024)
Posts: 4319
Topic starter
 

Hi Klaus,

nice input!

About moving rigs. I find movement parallel to the sail surface to be unvanted and not comparable to pumping. Reversal of flow can never be good in my opinion. This is the movement (pitching) I think about when discussing movement. Movement in the other axises might be good but force lost due to elasticity does not sound good on a racing sailboat unless there are handling issues.
Stays that are

flexible

to a certain degree would improve on the jib, but starting to design this into the rig is very complex and with uncertain gains in my opinion. I would prefer to pull on some more downhaul and continue running the mainsheet and accept the jib draft increase.

Agree on the T foils! But they dont seem to be

in vouge

anymore.

5mm is probably a bit much but the matieral properties would be the deciding factor.

UV should not be an issue if the fibers are protected by a heat shrink tube. Epoxy is a well known property regarding UV and water. The remaining question is how water affects carbon fibers in the long run.

Very interesting discussion. Thanks for adding to it Klaus!


 
Posted : October 1, 2012 4:57 am
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