Well, looks like my idea to install dyneema forestay be no more.
Recently watching rigging doctor about what they have with dyneema rigging.
In cold weather dyneema loosing tension and in hot snap to tension.
His rigging was all loose, didn't eat to tension afraid that if temp wet up, dyneema would snap something.
Looks like back to furler and use dyneema for soft shackles al over only.

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Kryspen said..
Well, looks like my idea to install dyneema forestay be no more.
Recently watching rigging doctor about what they have with dyneema rigging.
In cold weather dyneema loosing tension and in hot snap to tension.
His rigging was all loose, didn't eat to tension afraid that if temp wet up, dyneema would snap something.
Looks like back to furler and use dyneema for soft shackles al over only.

Got a link to that episode?

This one from 2015 mentions it.www.riggingdoctor.com/life-aboard/2015/10/2/life-cycles-of-dyneema

And this one from 2020 is specifically about effect of trmperature on length: www.riggingdoctor.com/life-aboard/2020/4/10/dyneema-and-its-coefficient-of-thermal-expansion

Given there are various versions of Dyneema about (SK75, SK78, SK99), plus pre-stretched versions, unclear if the coeff of thermal expansion is constant across all.

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Quixotic said..
This one from 2015 mentions it.www.riggingdoctor.com/life-aboard/2015/10/2/life-cycles-of-dyneema

And this one from 2020 is specifically about effect of trmperature on length: www.riggingdoctor.com/life-aboard/2020/4/10/dyneema-and-its-coefficient-of-thermal-expansion

Given there are various versions of Dyneema about (SK75, SK78, SK99), plus pre-stretched versions, unclear if the coeff of thermal expansion is constant across all.

Thanks

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julesmoto said..

Kryspen said..
Well, looks like my idea to install dyneema forestay be no more.
Recently watching rigging doctor about what they have with dyneema rigging.
In cold weather dyneema loosing tension and in hot snap to tension.
His rigging was all loose, didn't eat to tension afraid that if temp wet up, dyneema would snap something.
Looks like back to furler and use dyneema for soft shackles al over only.

Got a link to that episode?

Select to expand quote

julesmoto said..

Kryspen said..
Well, looks like my idea to install dyneema forestay be no more.
Recently watching rigging doctor about what they have with dyneema rigging.
In cold weather dyneema loosing tension and in hot snap to tension.
His rigging was all loose, didn't eat to tension afraid that if temp wet up, dyneema would snap something.
Looks like back to furler and use dyneema for soft shackles al over only.

Got a link to that episode?

On YouTube .
He have to got underway using his engine ( electric ) afraid that his rigging might snap ( damage something if he tension dyneema while temp raise ).
Just wonder what grade ocean racing boats are using to avoid this problem .

I don't think this guy called The Rigging Doctor is necessarily that qualified. I also find his totally slack lifeline a bit unbelievable as I have dyneema lifelines on my NS38 and have never experienced that much slack (bad batch of Ebay Chinese Dyneema?).

The guys at Colligo marine should definitely know what they're talking about and they have this to say.


This is from a post on the subject from the cruisers forum here:

www.cruisersforum.com/forums/f116/dyneema-rig-goes-slack-in-the-cold-not-for-me-281479.html

I made sure that the stuff I bought was manufactured in Europe distributed by Ronstan.

Also from same thread:

I've gotten lots of good tips from the Rigging Doctor, but you need to beware, for example his dive into DIY Lithium was a disaster.

Have you worked out how much expansion/shrinkage you'll get in the different temperatures you'll sail in? I'd hazard a guess that the environment The Rigging Dr sails in has far more extremes in temperature than we'd get sailing in Australian waters. I'm looking at converting to dyneema but I must admit that this issue has given me some pause for thought. One degree of temp change will cause expansion/shrinkage for a 1 meter length of dyneema of 0.000012m's. So taking say a 20 degree temperature drop, this will cause a 10m shroud to shrink 20 x (0.000012x10) m's = 0.00024 meters = 2.4mm's. Not inconsequential, and even more so if one is sailing from the Gold Coast to Hobart via Cape Horn. Of course if one chooses the dyneema path it goes without saying that even under normal circumstances shroud tension should be checked much more often than SS. I guess it all gets back to how much you want to have dyneema and the perceived advantages vs the negatives.