RS600: stretchy halyard?

   I completely disagree with you. I am a rigger by trade and have been specing ropes for boats from oppies to the worlds largest super yachts.

Sk90 creeps a lot less. It is stronger. 

I highly recommend it for all applications where you wish to have no creep in a line.

Dm20 is a good product for stays, shrouds and forestays.

Sk99 is the new product that we will be using for non creep lengths from now on. 

All dyneema is produced by dsm.

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NHRC Send Private Message Find Member's Posts Visit Member's Homepage Posting king Joined: 13 Dec 13 Location: Lymington Online Status: Offline Posts: 102	Post Options Post Reply Quote NHRC Report Post Quote Reply Topic: RS600: stretchy halyard? Posted: 29 Jun 14 at 11:39pm
	I completely disagree with you. I am a rigger by trade and have been specing ropes for boats from oppies to the worlds largest super yachts. Sk90 creeps a lot less. It is stronger. I highly recommend it for all applications where you wish to have no creep in a line. Dm20 is a good product for stays, shrouds and forestays. Sk99 is the new product that we will be using for non creep lengths from now on. All dyneema is produced by dsm.

Paramedic Send Private Message Find Member's Posts Really should get out more Joined: 27 Jan 06 Location: United Kingdom Online Status: Offline Posts: 929	Post Options Post Reply Quote Paramedic Report Post Quote Reply Posted: 29 Jun 14 at 9:13pm
	Sorry but that doesn't bear out what the fibre manufacturers themselves claim, or what i've found on a variety of boats. According to DSM (The fibre manufacturer who supplies Marlow and English Braids) SK90 is stronger than SK78, but has similar creep to SK75. So i don't know what was going on with your Laser kicker, but i have found that poor quality rope - even using SK78 - is a waste of dyneema. The fibre is only part of the equation, the lay of the rope and the pre-stretch process have much to do with it and cheap rope is, well, cheap. Most dinghies will never need this extra strength, and we all want low stretch/creep. If you want ultra low creep you want DM20 aka Dynastay - i've used this instead of Vectran on a number of boats and it's very, very good. The rest is good advice tbf :) Edited by Paramedic - 29 Jun 14 at 9:26pm

NHRC Send Private Message Find Member's Posts Visit Member's Homepage Posting king Joined: 13 Dec 13 Location: Lymington Online Status: Offline Posts: 102	Post Options Post Reply Quote NHRC Report Post Quote Reply Posted: 29 Jun 14 at 10:58am
	Paramedic you are completely wrong about SK90. I have tried and tested it on a number of boats and it is the best product for no stretch applications. For example when testing a Laser Vang first part of the cascade in SK78 the result after a 20 minute sail in a 15 kt breeze was 65mm stretch With SK90 it was under 20mm 20mm would have been the splices bedding in. What I would add to this thread is that to reduce stretch/creep a). Use a good product, might not be cheap but it will last and wont fail. b). Work out the load that the line will carry and multiply that by a safe working factor of 4:1 to counter dynamic loading. Buy a rope diameter that will carry that Safe Working Factor c). Splice ropes wherever possible, knots cause failures, reduce the strength of the rope and degrade it massively d). Dont run un covered ropes through cleats as you degrade them very quickly e). Dont use high UV sensitive ropes (Vectran or Kevlar are most common), without checking and replacing them very very regularly.

Paramedic Send Private Message Find Member's Posts Really should get out more Joined: 27 Jan 06 Location: United Kingdom Online Status: Offline Posts: 929	Post Options Post Reply Quote Paramedic Report Post Quote Reply Posted: 27 Jun 14 at 9:17pm
	Don't buy SK90 for dinghies it has no advantages over SK78 for our purposes and is more expensive.

Jack Sparrow Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 08 Feb 05 Location: United Kingdom Online Status: Offline Posts: 2965	Post Options Post Reply Quote Jack Sparrow Report Post Quote Reply Posted: 27 Jun 14 at 5:27pm
	One thing to check if your old halyard is Kevlar. Kevlar doesn't like tight corners and has a habit of breaking at knots. You won't realise as the the kevlar core has broken inside the outer sleeve. You could be getting slip because you are actually only tensioning the sail with the outer sleeve of the rope which then stretches under load. Dyneema on the other hand creeps and takes a little time to bed in depending on the variety. But yes the SK78 (Excel D12 Max78) or SK90 (Excel Elite 90) minimise this to the Max and would don't the Kevlar sleeve trick as they don't mind corners. Edited by Jack Sparrow - 27 Jun 14 at 5:28pm
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bristolmustoskiff Send Private Message Find Member's Posts Groupie Joined: 20 Nov 12 Location: bristol Online Status: Offline Posts: 84	Post Options Post Reply Quote bristolmustoskiff Report Post Quote Reply Posted: 27 Jun 14 at 2:54pm
	you need the black rope with the kevlar in it 4mm last forever when you think you have pulled it up tie a loop in the halyard then tie the cunning ham to it and pull it tight that will take the stretch out of it
	live hard race harder

Neptune Send Private Message Find Member's Posts Really should get out more Joined: 08 Jun 09 Location: Berkshire United Kingdom Online Status: Offline Posts: 1314	Post Options Post Reply Quote Neptune Report Post Quote Reply Posted: 27 Jun 14 at 1:29pm
	£1 a metre.....yeah that's going to stretch again. Something like Excel elite with the SK78 core should be more like it at nearly £3 a metre (4mm should do it).
	Musto Skiff and Solo sailor

tgruitt Send Private Message Find Member's Posts Really should get out more Joined: 02 Dec 04 Online Status: Offline Posts: 2479	Post Options Post Reply Quote tgruitt Report Post Quote Reply Posted: 27 Jun 14 at 11:11am
	Also, don't hoist the halyard with the rope through the cleat as it wears them out really really quickly.
	Needs to sail more...

iGRF Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 07 Mar 11 Location: Hythe Online Status: Offline Posts: 6499	Post Options Post Reply Quote iGRF Report Post Quote Reply Posted: 27 Jun 14 at 9:00am
	I've just tried to correct this very same problem, 1st off it was worn cleats, so I changed them, then it was diagnosed as stretchy halyard, so yesterday took myself off to the Chandlers via an hours traffic hold up and asked for their recommendation. Dyneema core and its a£1 a metre came the reply, so 14 mtrs later and a lot of pfaffing around with fishing line and plumb weights (we'd already pulled the old one out by accident the race previously). Did it work? No, there was still a couple of inches, I'm hoping it was just new line 'stretching in' but am going to be gutted if it happens again on sunday. The other thing we had problems with whilst I'm on, was spinnaker hoist going all curly then jamming in the block, we re roped that as well, but used some cheap stuff which seems to be ok so far, I've found that dyneema cored stuff to have more of a propensity for twisting than just plain 8 plaid, but would love to know the views of the hive mind. Edited by iGRF - 27 Jun 14 at 9:01am
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Rupert Send Private Message Find Member's Posts Really should get out more Joined: 11 Aug 04 Location: Whitefriars sc Online Status: Offline Posts: 8956	Post Options Post Reply Quote Rupert Report Post Quote Reply Posted: 27 Jun 14 at 8:39am
	All you have to do is pull the sail up, then put the downhaul on as tight as you can. Once you've let it off again, you'll find you can pull the halyard up more. Do this a couple more times until you are geting no more movement at the top of the mast.
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