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Old 05-02-2013, 15:59   #46
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Re: Standing Rigging Replacement

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Originally Posted by Stumble View Post
(...) the dyneema typically comes out 2-3 times the strength of the wire it is replacing. This means someone could cut thru more than half the line and it would still be stronger than the wire you have now. (...)
Not sure all engineers will agree with you.

BTW your experience with cutting dyneema/spectra differs from mine. I can cut thru 10 mm of bar-tight spectra with my diving knife in no time. I did not notice any blade dulling, much as Spectra seems harder to cut than say Polyester rope. (in contrast - I cannot cut thru our 6 mm 19-strand SS wires with the same knife).

You will easily notice too, that synthetic standing rigging (actually not too often made of spectra/dyneema) is nowadays protected by sleeves. Now you can educate me and tell me what the sleeves are made from.

b.
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Old 05-02-2013, 16:42   #47
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Re: Standing Rigging Replacement

Large LPG carriers use unsleeved Dyneema for mooring ropes. The manufacturer says sleeves are not needed but they are a habit with some specifiers. An LPG carrier breaking free in a gale is a tad more serious than a yacht rigging failure. In any case, signs of wear would give much more warning than ss crevice corrosion. For tropical use, I vote Dyneem No1, galv. No2 and stainless last.
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Old 05-02-2013, 17:28   #48
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Re: Standing Rigging Replacement

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Dock head,

.

I wouldn't worry about abrasion overly much. They spec for creep not strength, so the dyneema typically comes out 2-3 times the strength of the wire it is replacing. This means someone could cut thru more than half the line and it would still be stronger than the wire you have now. And having worked with this stuff before it is very difficult to cut. I use a ceramic "never needs to be sharpened" knife, and have to replace it every 5-10 cuts because the dyneema dulls the blades.
Not sure about that - abrasion is the worst enemy for Dyneema -thats why often it is best to sleeve if possible...I constantly keep an eye out for sheets to make sure they arent rubbing - just a screecher sheet rubbing for a few hours can start cutting fibres... as for finding it hard to cut with a knife - it slices through v easily - our safety device for cutting through in a dismasting scenario is a small tooth saw which would do the job v quickly....
Most riggers advise putting something like ropecoat on Dyneema if you arent sleeving just so it is easier to keep an eye out for cut fibres...
Sleeving can be a dyneema braid....but there are other alternatives too..on the dyneema lashings I cover with crepe bandage wound tight for extra UV protection as well...
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Old 05-02-2013, 17:31   #49
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I don't know how to word this without sounding prejudiced.


After looking at a lot of poured parts from India and the Pacific Rim, I am hesitant to buy cheap wire from a third world country. Where did the wire that folks got such great prices come from??
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Old 05-02-2013, 17:50   #50
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Re: Standing Rigging Replacement

IF you do the math the wire really doesn't wiegh that much and even a signifcant % reduction in wieght is not really that much in actual wieght. My boat has just under 300' of 1/4 wire and the masthead is 45' off the water, total 6 shrouds (lowers, intermediates and cap shrouds), back stay, topmast stay and head stay (2/3 up mast). I have a solid wooden mast. 7x19 319ss 1/4" is 0.11lbs/ft...that is a total of 30lbs of wire for my boat, 1x19 1/4" (wire more likely to be used on modern high tension rigs and w/norseman fittings) is 0.135lbs/ft
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Old 05-02-2013, 18:03   #51
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Re: Standing Rigging Replacement

DH
Have you had a quote from this guy, based in Gosport, heard good things about him, and meant to be reasonably priced
| Gosport Yacht Rigging at its Best
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Old 05-02-2013, 18:17   #52
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Re: Standing Rigging Replacement

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Originally Posted by DumnMad View Post
(...) For tropical use, I vote (...)

galv. No2
and stainless last.

(...)
Why galvanized wire over SS?

THX.

b.
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Old 05-02-2013, 19:16   #53
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Re: Standing Rigging Replacement

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Originally Posted by barnakiel View Post
Why galvanized wire over SS?b.
With galv you know it needs changing when the rust shows. The risk of rust staining makes you change before any risk of failure arises.

With stainless it fails inside the crevices where there is lack of oxygen and you don't get the warning. I suspect the various recommendations for life span depend on where you are based. Something like 5 years for tropical, and 20 for cold climates. This summer a 5 year old cat lost its rigging near Fiji, - corroded inside the shiny exterior.
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Old 05-02-2013, 19:52   #54
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Re: Standing Rigging Replacement

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Originally Posted by barnakiel View Post
Not sure all engineers will agree with you.

BTW your experience with cutting dyneema/spectra differs from mine. I can cut thru 10 mm of bar-tight spectra with my diving knife in no time. I did not notice any blade dulling, much as Spectra seems harder to cut than say Polyester rope. (in contrast - I cannot cut thru our 6 mm 19-strand SS wires with the same knife).

You will easily notice too, that synthetic standing rigging (actually not too often made of spectra/dyneema) is nowadays protected by sleeves. Now you can educate me and tell me what the sleeves are made from.

b.
The most abrasion and cut resistant line made today is actually dynema. Which is why the best abrasion sleeve for dynema is actually a slightly larger piece of it spliced over the wear area. The same material is one of the only non-metal fabrics that is approved for cut resistant gloves by OSHA, and after dragging trees thru the forest floor the Oregon study on using it in place of steel cables basically said that anyone who doesn't switch is making a mistake (in reality the ended the study because dynema was so much better that there was no reason to continue studying it).

As for synthetic rigging, there are a number of different materials used. Everything from PBO which is wholly unsuitable for a cruising boat, to carbon fiber pultruding rod also unsuitable, to dynema (really Dynex Dux). The cover depends on the underlying material... PBO fails in hours when exposed to UV so it's cover is all about UV protection, the dyneema' problem is also UV and is geared to that. The carbon rod... No idea it's issue is that it fractures from sudden impacts.

Different materials require different coverings.



Wolf,

The absolute weight is one thing, now figure out the additional righting moment.

If we assume that you have 30lbs of wire plus 30 pounds of fittings.., and the average height above the CE is 30' (half the height above water, plus a little since the weight is concentrated high up, and the CE is going to be below the water line). Then switching to dyneema would save you roughly 60lbs*.14 (dyneema rigging usually comes out at 1/7 the weight of stainless) = 8.57lbs

So for your stainless:
60*30=900foot pounds of righting moment
For dyneema
8.57*30=257

So you save about 645foot pounds. Or the equivalent of increasing the mass of a standard 5' foot deep fin keel by about 300lbs.
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Old 06-02-2013, 00:34   #55
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Re: Standing Rigging Replacement

Dockhead,

We've gone almost exclusively to Die-form wire, because one can rely on its composition, and for a given diameter it is stronger than 1 x 19 s/s.

Ann
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Old 06-02-2013, 05:45   #56
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Re: Standing Rigging Replacement

THX everybody above for posting all the precious bits and pieces of information, opinions and experiences. Life is a learning curve and we are blessed with living in times when change is rapid and we can witness it all going from good to better.

I thought I would share these two pieces of my experience too:

I think some of SS criticism (to be used as standing rigging, in the tropics) is not just. I state this because we have two backstays here which came with the boat back in 2003 (age unknown back then) sailed us rtw and now they are here with us in probably the most corrosive environment one can imagine (Sahara dust loaded with corrosive particles). Look brand new. Due for replacement before any serious sailing.

My guess is then, that plenty of SS rigging failure comes when parts are not sized adequately and, perhaps twice as often, when they are not aligned properly - lack of toggles, bad entry angles, and resulting breaking/bending loads, etc..

As re synthetic replacements in (typical) cruising boat, I believe one should weigh the benefits (clear for racers but perhaps not quite so for an average cruiser) against the factors that may (or not) count too: if the weight of the replacement is less, the boat's movements will get more 'nervous' and also windage may grow (the synthetic rigging I have seen was all considerably larger diameter than equivalent rod or 19SS rigging).

Well, I hope these 2 cents of rigging experience help someone too.

Cheers,
b.
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Old 06-02-2013, 06:51   #57
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Re: Standing Rigging Replacement

For anyone considering synthetic rigging:

It may be a great option for "some" rigs that are either very insensitive to rig tune, OR are sailed within a 30 degree temperature range. but for many boats, it could be a disaster.

A case in point would be on my tall, skinny, double spreader, "cutter" rig, where the relative static tension on each shroud/stay needs to stay the same, to keep the mast in column.

I have DUX synthetic on my running backs, (only), and this is a perfect application, because they have folding handle "quick adjust" turnbuckles. I tension them only as needed.

Just to make convenient grab handles for boarding the boat, I have them snug at 70 degrees. WITH NO FURTHER ADJUSTMENT:
At 99 degrees they would be banjo string tight. (Twang!)
At 45 degrees they would be hanging TOTALLY slack, to the point that I can move the runner around in a 1' circle with two fingers!

This was never true with the wires that the synthetic replaced! With temperature fluctuations, the wire and mast expanded and contracted more or less together. NOT TRUE with synthetic. The mast may contract on a cold day at many times the rate of the DUX, causing this 10X tune variation.

This is not a problem on my quickly adjustable runners, in fact the DUX is great here, and flops around far less, being so light. IT WOULD BE A DISASTER on the rest of my rig!

The problem is that the static load on an upper shroud may be reduced by 50% on a cold day/season. while in the same situation, the static load on the lowers might only have changed 25%. This is because with BOTH of the synthetics staying more or less the same, (hypothetically... I have no hard numbers), the top of the mast is perhaps 1/2" shorter. while the bottom half of the mast might only be 1/4" shorter.

The net result is the opposite of what one wants to keep a tune sensitive mast in column. Going from a warm day or season to cold, with no adjustments, you end up with a much slacker rig, and tighter lowers than uppers. (= MAST BEND)

Depending on your rig and sailing climate... For some it may be fine, but not for others.

Something to bear in mind in your rigging decisions.
M.
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Old 06-02-2013, 07:12   #58
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Re: Standing Rigging Replacement

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Originally Posted by Ann T. Cate View Post
Dockhead,

We've gone almost exclusively to Die-form wire, because one can rely on its composition, and for a given diameter it is stronger than 1 x 19 s/s.

Ann
Very good points Ann; I had never thought of the composition / quality assurance aspects of Die-form before
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Old 06-02-2013, 07:34   #59
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Re: Standing Rigging Replacement

Poor Dockhead has elicited a barrage of opinions. I think Wolfenzee has defined the route that I will take. Idora has a heavy old fashioned ketch rig with dual back stays.. There are so many inners,uppers and lowers ect. ect. That it's nothing but a big old expensive project. Shoot, I need over a hundred 1/2" 316 SS bolts just to re-up the chain plates. I will ultimately replace all of it...the most critical parts first, beginning with the bobstay. My goal is to have her in shape to do a round Van Isle when I retire...that gives me 2 years to get it done. Until then I must be conservative with what I do. Which is hard since the boat eggs me on like a big old Labrador who wants to go out and play.
Sure wish I had a fwd looking IR cam.

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Old 06-02-2013, 07:54   #60
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Re: Standing Rigging Replacement

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....but there are other alternatives too..on the dyneema lashings I cover with crepe bandage wound tight for extra UV protection as well...
Now I remember -- it was 6000 pounds to replace the lashings and do a full rig inspection on a Dyneema rigged boat -

So the lashings have to be replaced often? Those of you who have tried it, what are the real running costs like for a Dyneema rigged boat?
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