Stainless bottle screws Vs Dyneema

Sixpence

Sixpence

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For those that don't already know, my boat is an old 21ft Debutante that is currently being worked on in anticipation of launching her at the end of April. However, one of the remaining tasks is that of replacing the old (and not looked after) bottlescrews.
I understand that modern racing yachts are using Dyneema more and more, instead of stainless bottle screws. The standing rigging is fine, so what is the opinion of the forum ?
Do I continue to search for a reasonably priced source of bottle screws or do I switch to the modern Dyneema method, and if so, any tips on tensioning ?

More info here

Here it states its uses include replacing bottle screws

Anyone tried it ?
Opinions please

Apologies for double posting
 
Thanks for the link Clive , but I'm also after opinions on Dyneema . Good enough for racing boats so why not small slug boats like mine , and it still works out cheaper with the added benefit of being able to carry lots of spare without it rattling around in a locker making a racket
 
On the rig stresses on a Deb I'd have thought short lanyards with ordinary prestretched terylene would have been quite adequate - I've used this on a very similar sized boat and never had any trouble - actually preferred it to turnbuckles.
 
Excellent site , thanks
This seems to be on a 63ft boat so it can be done

Looks similar to your description too John ?

shroud_on_63_feet_trimaran.jpg
 
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On the rig stresses on a Deb I'd have thought short lanyards with ordinary prestretched terylene would have been quite adequate - I've used this on a very similar sized boat and never had any trouble - actually preferred it to turnbuckles.

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Agreed, a good cheap solution, I think just make the line off to the chain plate reeve it through the terminal and chain plate, probably 4-5 parts will be enough of 3mm Dyneema to get sufficient tension, then make it off round the lot covering the hitch at the chain plate to tidy it up.
 
Interesting thoughts. Many boats in the past have had rope standing rigging, and deadeyes are still used. I see no reason why you couldnt rig your boat with dyneema, but equally I cant see a reason why you would want to do so except for cost.

To put it another way, if it were a better / cheaper alternative to wire / rod, then I think you would see some boatbuilder in the competitive market offering it.

And whilst your boat is no doubt lovely and well loved, its not the sort of boat that would benefit from the latest sh*t hot racing technology is it?
 
The only places that I can see the claim for replacing bottle screws refers to lacing braid. I interpret this as meaning on guard wires. A friend of mine went for a test sail in the Clyde one February. He was leaning on the guard wires near the pushpit when the worn lacing broke and he went over the side. He was not wearing sailing clothing and was lucky not to have suffered hypothermia or worse. Since then I have always used bottle screws on guard wires.

Nowhere can I see a suggestion that Dyneema replaces rigging bottle screws. Perhaps I haven't looked carefully enough. Personally I think it's a bonkers idea. Why use a piece of string that can be cut with any sharp object. Even if you don't do it, what about guests, vandals, rats? How long does it take a warp tied off somewhere to chafe through 3 mm Dyneema?
 
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And whilst your boat is no doubt lovely and well loved, its not the sort of boat that would benefit from the latest sh*t hot racing technology is it?

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Not sure whose boat you are refering to, mine or the OP?, but I personly have no intention of changing my s/s screws.
 
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Why use a piece of string that can be cut with any sharp object. Even if you don't do it, what about guests, vandals, rats? How long does it take a warp tied off somewhere to chafe through 3 mm Dyneema?

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Isnt Dyneema the same as kevlar? The material that is use for police anti stabbing vests? In which case the chances of cutting or rubbing through are minute.
 
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The only places that I can see the claim for replacing bottle screws refers to lacing braid. I interpret this as meaning on guard wires. A friend of mine went for a test sail in the Clyde one February. He was leaning on the guard wires near the pushpit when the worn lacing broke and he went over the side. He was not wearing sailing clothing and was lucky not to have suffered hypothermia or worse. Since then I have always used bottle screws on guard wires.

Nowhere can I see a suggestion that Dyneema replaces rigging bottle screws. Perhaps I haven't looked carefully enough. Personally I think it's a bonkers idea. Why use a piece of string that can be cut with any sharp object. Even if you don't do it, what about guests, vandals, rats? How long does it take a warp tied off somewhere to chafe through 3 mm Dyneema?

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Blimey Nelson and Co. would have been alarmed about your predictions re the demise of their standing rigging, chafe, rats, vandals (in Nelsons case, he would be keeping his one eye on Frogs and Spans though, eh!), GUESTS, who do you invite aboard???

As for your friend, be fair, it was a TEST sail, the badly maintained guard rails were VERY well tested to destruction.

Seriously, I am Very Glad he was OK! Bill.
 
<<< Isnt Dyneema the same as kevlar? The material that is use for police anti stabbing vests? In which case the chances of cutting or rubbing through are minute. >>>

No, it's UHMWPE, Kevlar is an aramid. Dyneema is easily cut with a knife or any other sharp object. There's a world of difference between the relatively heavy rope used on a man of war and a few coils of 3 mm string.

I'm not suggesting that guests go about deliberately cutting bits off your boat but accidents to very light line can easily happen. The whole thing is totally unnecessary IMHO, do the job properly with metal fittings that are virtually fool-proof.
 
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The only places that I can see the claim for replacing bottle screws refers to lacing braid. I interpret this as meaning on guard wires. A friend of mine went for a test sail in the Clyde one February. He was leaning on the guard wires near the pushpit when the worn lacing broke and he went over the side. He was not wearing sailing clothing and was lucky not to have suffered hypothermia or worse. Since then I have always used bottle screws on guard wires.

Nowhere can I see a suggestion that Dyneema replaces rigging bottle screws. Perhaps I haven't looked carefully enough. Personally I think it's a bonkers idea. Why use a piece of string that can be cut with any sharp object. Even if you don't do it, what about guests, vandals, rats? How long does it take a warp tied off somewhere to chafe through 3 mm Dyneema?

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Of course you're entitled to your opinion but I would appreciate it if you didn't say I was bonkers for having mine . I intend using 5 or 6 mm so not the 3mm 'string' you're talking about , and the incident you're talking about is purely down to poor maintenance not revealing a fraying line . A bottle screw is just as likely to fail if it's not checked but to say it's 'doing it properly' to use metal fittings is plain daft . There is no 'properly' which is why I asked the question . You obviously have your opinion on my idea and thanks for telling me what it is but I like to look at all the alternatives , and bottle screws are not the only way to do the job
IMHO of course
 
I agree with T25, and have been very interested in following this thread, because the same thoughts had occurred to me.

WRT "doing things properly" - there is a difference between doing things effectively and doing them because that's the way things have traditionally been done. IMO the sailing community is very conservative, and there are materials and techniques from other disciplines which would/should supplant current practise if they were more widely known. I mean - what about that new-fangled s/s stuff when wood and manilla deadeyes have worked for donkeys years?? /forums/images/graemlins/grin.gif
 
Is it just me, or does this look like the method of setting up stays used on HMS Victory (and all other boats of similar vintage)? Using a lanyard and deadeyes is a pretty traditional method. And I guess that if it was OK for Nelson and centuries of other sailors, then there is nothing fundamentally wrong with it!

I don't see why you need an enormously strong material. The breaking strain only needs to be the breaking strain of the stay being tightened divided by the number of turns. Of course, you would overestimate that to allow for fraying and UV damage, but the great advantage is that if anything is going wrong with it, you'll see the damage - unlike a bottle-screw, where a fatal flaw migh develop in a place completely invisible to visual inspection.
 
There used to be a good reason for using lacing on guard wires - or perhaps that was an urban myth! Theory was that a continuous loop of wire round the boat made RDF (remember that ?) ineffective. The string bits broke the circle.
 
I had a boat, dating from 1970 with small insulators in the guard rails, presumably based on the RDF theory. The other reason that I have seen for lashings is that they are easily cut in order to aid MOB recovery.
 
Yes it was regarded as a real no no to have an unbroken conductive ring, was it because it affected the handbearing compass on the RDF? very good point re. the MOB!
As I said in a earlier post, I think 5turnsx3mm dyneema would be neat and plenty strong enough for the proposed rig on a 21ftr.
 
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