Spectra rigging? What do you think

[snort]

Originally Posted by Training Wheels

Chafe concerns me too. Met a couple who had dyneema rigging and their capshrouds and aft lowers were all wrapped with tape because the main would chafe them. Plus, always worry about some pissed off guy with a machete!

The pissed off guy with a machete probably has the means to get a hold of a bolt cutter as well.

[RaymondR]

On my previous boat I carried a length of 1 19 SS with a couple of Staylok fittings for emergency repair purposes. I'm going to look into getting a length of Dyneema for the same purpose on this boat. Looks like it would be far more convenient than the wire was.

[Benz]

For everyone worried about chafe, there are many varieties of covers available, from Dyneema sleeves to PVC chafe guards called "Spiroll" I have a little of both on my synthetic rigging, but I can testify that chafe is not really a problem.
I plan to take one of my shrouds to destruction test, just to see what it will have done in six years; I'll post results on this forum when I do (it may not be this year, but it's in my heart to do it).
For those worried about vandalism: why stop at shrouds? Why not worry that a rock could smash your portlights? or a machete cut your docklines? or your nylon rode? You might as well worry that some vandal will break in and rearrange your sock drawer while leaving the toilet seat up.
Casual vandals aren't really smart enough to target rigging specifically, and anyone who hates you enough to want to damage your rig can easily do so no matter what it's made of.

[etesian]

I re-rigged my Alberg 30 with colligo Dux 4 years ago. I haven't covered any of it and chafe doesn't seem to be a problem. The only area that has a little fussiness are the forward lowers where the genoa sheets drag. Not enough abrasion to worry about. I went with 9mm dux all around to keep it simple so the lowers have a pretty good safety margin. I also kept the forestay as wire. One oddity is the thermal elongation and contraction of the rig. This could be a big deterrent for some. I keep the boat in British Columbia so we have a fairly large temperature swing seasonally as well as daily. My rig goes totally slack in the winter and during the first warm spell usually around May it will be bar tight if I'm late in adjusting the turnbuckles. In the spring and fall it will change noticeably from day to night where we can have frost in the mornings then 25c during the day. Needles to say I do a lot of screwing in and out of turnbuckles. I actually leave them un pinned because of this. Constant rig monitoring... lol It not a bad thing actually. In a different climate especially somewhere tropical I bet the rig tension changes would be barely noticeable and a non issue. For now its fine with my smaller rig but I'm building a Cape George 38 and I don't think I'm going to go dux because of this. A 50+ foot double spreader rig that has to be tuned continually is just to daunting a situation. I wish it weren't this way because I really like the stuff. I recieved an email from Colligo showing more pull test data and it looks like after 10 years the stuff is at 40% strengh. Thats still as strong as new wire would be. Seems that during its working life it has one hell of a safety margin. Pretty cool stuff.

Kristian

[Snowpetrel]

^^ thanks. Very interesting, and thermal expansion is one thing that puts me off at the moment, especially for aluminium masts. The thermal expansion coefficient of spectra is negative where as alloy is positive. So as it cools down the specta elongates and the alloy mast shrinks. A wood or carbon mast would be much better in this regard.

[Benz]

Originally Posted by etesian

I re-rigged my Alberg 30 with colligo Dux 4 years ago. I haven't covered any of it and chafe doesn't seem to be a problem. The only area that has a little fussiness are the forward lowers where the genoa sheets drag. Not enough abrasion to worry about. I went with 9mm dux all around to keep it simple so the lowers have a pretty good safety margin. I also kept the forestay as wire. One oddity is the thermal elongation and contraction of the rig. This could be a big deterrent for some. I keep the boat in British Columbia so we have a fairly large temperature swing seasonally as well as daily. My rig goes totally slack in the winter and during the first warm spell usually around May it will be bar tight if I'm late in adjusting the turnbuckles. In the spring and fall it will change noticeably from day to night where we can have frost in the mornings then 25c during the day. Needles to say I do a lot of screwing in and out of turnbuckles. I actually leave them un pinned because of this. Constant rig monitoring... lol It not a bad thing actually. In a different climate especially somewhere tropical I bet the rig tension changes would be barely noticeable and a non issue. For now its fine with my smaller rig but I'm building a Cape George 38 and I don't think I'm going to go dux because of this. A 50+ foot double spreader rig that has to be tuned continually is just to daunting a situation. I wish it weren't this way because I really like the stuff. I recieved an email from Colligo showing more pull test data and it looks like after 10 years the stuff is at 40% strengh. Thats still as strong as new wire would be. Seems that during its working life it has one hell of a safety margin. Pretty cool stuff.

Kristian

I don't see huge thermal changes, but my rigging is Vectran, not Dyneema. If I tune the rig nice and tight in the spring, it stays good all summer.
But Kristian, the Cape George 38 you're building is the perfect candidate for a schooner rig. With two smaller masts, and a lot less rig tension required, synthetic would be perfect. And schooners look way cooler than sloops.

[Snowpetrel]

Originally Posted by Benz

I don't see huge thermal changes, but my rigging is Vectran, not Dyneema. If I tune the rig nice and tight in the spring, it stays good all summer.
But Kristian, the Cape George 38 you're building is the perfect candidate for a schooner rig. With two smaller masts, and a lot less rig tension required, synthetic would be perfect. And schooners look way cooler than sloops.

Interesting choice, I understood vectran was more UV sensitive than Dyneema, though some of the test result seem to show it stabilizing faster. The thermal expansion and creep issues seem much better for vectran, but it is still negative. Do you have a wood or alloy mast? Here is a couple of approximate comparisons of Coefficient of linear thermal expansion. Note the huge differences between Aluminium and Dyneema.

Vectran -4.9 x 10-6 1/K

Dyneema -12 x 10-6 1/K

Aluminum +24 x 10-6 1/K

Stainless +16 x 10-6 1/K

Wood +4 x 10-6 1/K

Carbon fibre layup 0 x 10-6 1/K depending on layup.

https://www.google.com.au/url?sa=t&s...8VCzYdWYc6klfP

Saying this on a simple inline rig exact tune is not so critical. But I'd be a bit worried on a swept spreader rig that relies on a tight rig to stabilise the mast fore and aft.

[fxykty]

So I guess that anyone planning on sailing in higher latitudes and/or wintering should avoid synthetic rigging? Having to adjust twice a day seems like a PITA and really increases the chances of a rig failure. Thoughts?

[Snowpetrel]

Originally Posted by fxykty

So I guess that anyone planning on sailing in higher latitudes and/or wintering should avoid synthetic rigging? Having to adjust twice a day seems like a PITA and really increases the chances of a rig failure. Thoughts?

I don't think its that bad, more a summer/winter thing. Manageable if you are proactive with rig tune, but not set and forget. Probably not an issue in the tropics. But down here winter often gets down to 0 deg Celsius and summer is up to 30+ degrees. It also shows the importance of keeping masts and dyneema reflective low heat absorbing colors rather than dark colors.

Some very rough back of envelope calcs seemed to suggest that a 30 deg temp change would roughly change the prestress in the dynex by about 10%. So if you tuned your rig to 10% of break (Stainless wire at 15 degrees) it would range from 5%-15% at 0° and 30°. Just about acceptable for an inline masthead rig, but not so good for a frac swept spreader rig where shroud tensions often need to be more around the 20-25% range to keep the forestay tight and stop pumping. Still this is all just theory on my part. I am interested to hear real world data.

[Benz]

Originally Posted by Snowpetrel

Interesting choice, I understood vectran was more UV sensitive than Dyneema, though some of the test result seem to show it stabilizing faster. The thermal expansion and creep issues seem much better for vectran, but it is still negative. Do you have a wood or alloy mast? Here is a couple of approximate comparisons of Coefficient of linear thermal expansion. Note the huge differences between Aluminium and Dyneema.

Vectran -4.9 x 10-6 1/K

Dyneema -12 x 10-6 1/K

Aluminum +24 x 10-6 1/K

Stainless +16 x 10-6 1/K

Wood +4 x 10-6 1/K

Carbon fibre layup 0 x 10-6 1/K depending on layup.

https://www.google.com.au/url?sa=t&s...8VCzYdWYc6klfP

Saying this on a simple inline rig exact tune is not so critical. But I'd be a bit worried on a swept spreader rig that relies on a tight rig to stabilise the mast fore and aft.

My shrouds are made with polyester-covered Vectran, so they're pretty well shaded, though I'm hearing that some sunlight manages to leak through the cover--hence my desire for a destruction test of one of them.

My mast is alloy, but it's short, since I ship a gaff mainsail on it. There's a barely detectable slacking of the shrouds on chilly mornings, but not enough to make me want to take up on all the lanyards. I try to do my spring tune on a chilly early morning, and it all stays just right for the rest of the season.

I will say, though, that my low-aspect-ratio gaff-headed cutter rig isn't very shroud-tension dependent; there's no pre-bend, no aft-swept spreaders--it's kind of a great rig for hand-tuned shrouds with a critical eyeball up the length of the mast to check for column. Knowing very little about other sorts of rigs--fractional and swept and pre-bent and all, and having no use for them whatever (why fix what ain't broke? a gaff rig's the best thing for my sort of boat), I can't comment on the usefulness of synthetic shrouds for them. Stone-age designs like that might just have to stick with stone-age shroud materials like rod or dyform...too bad for them.

[Snowpetrel]

^^ Ha, thanks Ben, I pretty much agree with you on your rig choice! Its very hard to beat the simplicity of your rig, and it very tolerant tune wise. Even a simple in line bermudian cutter rig like the Cape Georges are designed with does not get too twichy tune wise, especially if it all adjusts tension approximatly similarly as it would in this case.