Dyneema Guard Wire?

nickd

nickd

Well-Known Member
Joined
29 Sep 2009
Messages
623
Location
Barmouth
Visit site
Hi
I have to replace my guard wires on my Konsort. I am thinking of using Dyneema instead of stainless wire and wondered if anyone else has done this and if they have how have they connected it to the pulpit, and also what the pros abd cons are
Many thanks
Nick
Southern Comfort
 
nickd said:
Hi
I have to replace my guard wires on my Konsort. I am thinking of using Dyneema instead of stainless wire and wondered if anyone else has done this and if they have how have they connected it to the pulpit, and also what the pros abd cons are
Many thanks
Nick
Southern Comfort
Click to expand...

Not done it, but using a cord link that can be cut is common with wire guardrails.

The risk of attachment to the pushpit/pulpit is sharp edges chaffing through the cord, so put a D shackle through the hole on the pulpit & tie to that.

You may also want to consider what wear you're going to get where the dyneema guardrails pass through the stanchions and how you can eliminate that.
 
I’ve had a set on for about 5 years – 8mm Dyneema. No wear. My stanchions have hard plastic inserts. I have small thimbles and shackles at the pushpit end and small turnbuckles at the pulpit end.

It’s difficult to get and maintain quite the same tension as with wire.

Other than that, no problems at all – more agreeable to hold (or fall against!) and easier to replace or repair than wire.
 
dyneema shackles

pvb said:
Surely the problem is chafe at the stanchions, not at the shackles?
Click to expand...
. As I see it, simonfraser was making the point that dyneema can't be very prone to abrasion if it's used in the so-called soft shackles which would thread through s/s cringles. I'm currently "road testing" two such soft shackles - one for jib sheets on an 18 footer and one for genoa sheets on a 29 footer. They work well and I tend to forget that they're there but it's early days so far.
 
Is there a possibility that the dyneema, though stronger than steel, might be too thin to be held easily ?

FWIW we have 3mm stainless wire, and that can be difficult to hold under certain circumstances.
 
sarabande said:
Is there a possibility that the dyneema, though stronger than steel, might be too thin to be held easily ?

FWIW we have 3mm stainless wire, and that can be difficult to hold under certain circumstances.
Click to expand...

3mm is too thin and current rules or guidelines on raceboats I think is 4mm minimum. We replaced our plastic covered ones with one size larger S/S ones on the top rail and original sized uncoated ones on the lower rail.

I don't understand the Dyneema idea at all. Dyneema is expensive and the risk of chafe makes it a no brainer to me. It makes excellent halyards etc but I fail to see any advantage for guardrails.
 
Dyneema

Tried it once thinking it would be more user-friendly. It is, but not for long and had to replace PDQ.
Don't waste your money - stick to bare stainless, wearing gloves if you have to!
 
Thanks for all of your replies
My reasoning for considering dyneema is as follows:
It is as strong/stronger than steel
It is easier to work with, I can splice the end
It can be cut anywhere in its length in an emergency
It may be more aesthetically pleasing
I can carry a spare length.
It would be marginally cheaper

The only downside I can see is chafe where it goes through the stanchions.
The top guide in the stanchion is a polished ring, so the top line will be ok, the bottom line I was thing of gettting some appropriate diameter hose to sleeve the dyneema where it goes through the stanchion.

Tom - "Tried it once thinking it would be more user-friendly. It is, but not for long and had to replace PDQ"
Why not for long was it chafe?

Thanks for all your input
I have to replace the starboard side due to storm damage this weekend, so I may take the plunge and o one side and see how she fares for the rest of the season.
 
glow in the dark

i think this is one advantage of dyneema


http://www.glorope.com.au/catalog/

you can make your guardrails glow in the dark, i think they are the same people that do the sail draft stripes.

I know a lot of the race boats are using dyneema and i 'think' it is now allowed by ISAF although not 100% sure.

In my mind dyneema has a fundamental problem, it is stronger and less stretchy than wire but we are reluctant to belive it. i think from a chafe point of view everything can be overcome.
 
I think the 'strength' of dyneema may actually be a problem. Steel has a certain amount of elasticity followed by a certain amount of deformation before failure. In stretching it absorbs some energy of impact. Dyneema might snap where steel gives.

The impact of a fat bloke hitting the middle of a taut wire translates into a lot of tension for a short while.
Also chafe is easily underestimated. Dyneema halyards on my dinghy have to be shortened to move the chafe point every couple of months, otherwise life is under a year. There are also potential UV issues, I know UV coated dyneema is available, but on a guardrail, the coating may get rubbed off.

Maybe these issues have been looked at in depth, I would look to ORC/ISAF/RORC guidelines.

You might also find that fittings on stanchions etc are different when designed for dyneema if high tech boats are using it. Whereas you can just lead stainless through a hole, you might want something different for rope?

Another point to be aware of is that rope will hold salt water against the stainless 24/7, causing pitting after a while, which will increase the abrasion, I've seen this with guardrail lashings. One reason to replace lashings every year!
 
You must log in or register to reply here.

Share this page

Top