Class rules

Frank are you saying buying a Dyneema backstay is cheaper than buying a a standard 1x19 - 3/16" dia with swaged on ends? Can you verify this for me.

Thanks Dan,

By-the-way, same with making a new backstay. If you can do a brummel splice, you can make a back stay. Also about price: There are many grades of dyneema, but all stronger than steel. There is SK 75, SK 78, and SK 90, then such things as Dynex Dux. You can also order dyneema winch line from China via Ebay, etc, where you can buy 5mm for the life lines, or back stay, etc, for about $.50/ft. I also purchased some yacht braid for them in 8mm (5/16') with a dyneema core and polyester jacket. I purchased six rolls of 50m each. The advertised price was $128/roll, but since I bought 6 rolls he discounted it to something like $100. This material is beautiful, but not suitable for tapering, because the core is not UV protected as are the cores from New England ropes, Samson, etc. They are nice lines though.

Regarding Dynex, I think the class might be able to negotiate a deal on a their 5mm from Colligo Marine. The owner's name is John. His company is the one making the most effort in promoting Dynex into the recreational marine community. They offered to rig my entire boat in Dynex, including standing rigging, as a promotional thing. The local handicappers said that they would start out with a 3 point hit. As it happens, my boat is under the microscope by the rating people as it is, so I decided to not do it. As long as my boat is pretty much a conforming Laser, they can't very too much from the base rating. However we have here what we refer to as an X-boat, (something to which there is no reference or has been highly customized) and once you are an X -boat the rating people can assign any number they want to it. I don't want to trip into that.

The company in China I deal with is called YZ Ropes. Find them on Ebay.

The reason that Dynex can only be advertised as good for 5 years in the sun is because it hasn't existed longer than that for practical testing. The expect it to go much further. Also, you have no idea if your plastic coated life lines are good or not because where they start rusting is beneath the plastic. That's why most authorities don't allow them anymore. When I purchased Voila, the one thing on the survey report was the suggestion that I get rid of the plastic coated life lines. We trucked her from Portland to Blaine, and then sailed her from Blaine to Squamish, BC. Within an hour one of the life lines failed. I did a lash job and made a temporary fix. An hour later, a separate life line failed.

In my view, there is no case that can be made for steel compared to Dyneema for life lines and standing rigging other than for, perhaps, the forestay. I can't figure out how to accommodate the 72 diameters of bury in the 6.24 mm channel in the Carbo Foil.

I have the fresh water perspective and have never seen a coated lifeline fail and we have lots of boats here. But with the RRS mandating lifelines we will follow that and drop our own rule. The membership will need to decide if they want to allow dyneema for the B-stay. It certainly isn't a cost issue and it's been around for over 10 years. Sounds interesting. Thanks for your input 

In sailing, no single item breaks a boat loose and sends her on the plane other than say 50hp on the back. A boat's speed is the culmination of many fractions.
Weight aloft is a terrible thing for our Lasers. Recently I demonstrated to our crew in a practice the necessity of hiking hard. In the given breeze we were making 6 knots even with all hands on the rail and feet out. I then had the main trimmer turn around with his feet insider and the boat speed dropped to 5.74. That's about 500m per hour.......non recoverable. It seems like a little thing to have one's feet inside, but it is not. If you could put, say 3 or 4 pounds on the end of a pole of say 26' long and held it out and waved it around.....you couldn't. Now accelerate that weight as when going over chop and hitting a wave, and the inertia of the mass is huge. Worse, hang it all out to leeward on the end of a long stick.   Much worse than one crew with his feet inboard. Boats far bigger and more stable than ours, are meticulous at reducing weight aloft. Voila lives on the hardstand together with a fleet of Farr 30's. None have steel back stays or cascades, all their antennas are on the push pit, many halyards start at 6mm and taper from there.

After all, we are all trying to go 6 mph just a little faster than the next guy. Fractions make the difference if you are a racing sailor.

Life lines and for certain the back stay. Then dump all the stainless steel wire in the cascade system and replace it with any of the Dyneema's. You don't need Dynex for that. Just some Amsteel or anything in the 1/8 - 3/16 range will do for the cascade. You will be very happy with it all.

If you decide to go with more Dynex for standing rigging, I would not worry about the rig falling down. The steel shrouds that are standard on the Laser have a tensile strength of 4,400 psi. The 5mm Dynex Dux that would replace them is rated at 11,000 psi and weighs 1/7th as much as the steel. Then you can also take the heavy rusting bolt cutters off the boat, and just keep your rigging knife sharp. The use of Dynex is rigging is not a cheaper step down. It is an improving step up both in safety and boat performance.

A few years ago on the boat I crew on, we bought a new jib halyard as the old one had terrible meat hooks in the 1x19 stainless (yes, we were actually using stainless 1x19 for a halyard).  We upgraded to dyneema. 

Seemed like a great idea until the first time we hoisted the genoa with the new halyard, five minutes into the Wednesday race the line broke.  Turns out a sheave at the top of the mast where the line entered the mast had some sharp edges, most likely from the abuse of the meat hook (chicken or egg I'm not sure but I digress).

My point is, Dyneema is super strong and super thin, but you'd better keep it away from sharp objects.  Hoisting your genoa back up with the other halyard is one thing.  Losing your backstay is something else.  Yes, I know the L28 will survive a blown backstay, but I'm just saying is all...

Frank, What toggle do you use for the b-stay at the masthead crane? Or do you attach to only one side? and do you use a thimbal on the bottom end?

frfletch wrote: When I bought my boat in 2008 it had a spectra (dyneema) back stay that had been on it for years. It also had spectra tapered halyards that went back to 2005, still good. I have since changed the back stay and down sized it to 4mm and shortened it, and all halyards are dyneema and tapered. No problems with anything. If you have burrs on your sheave boxes, they were caused by the wear from the rubbing of the previous stainless wire halyards that wear on the sides. My boxes are fine and there is zero wear on my halyards. Our halyards are 1/4" before tapering, so we are only 1/8" dyneema on the core.......no failures nor wear on the halyards at all. Regarding standing rigging, they do use standard turnbuckles for take-up, though multiple lashings are an alternative, mostly used on cruisers and multi hulls. Boats like ours use turnbuckles. Dux creeps very little as it is already pre-stretched. There is initial movement, but it is the mechanical take-up of the splices and settling into the terminating thimbles. Once that is taken up, there is no creep in the line. I am not trying to sell the stuff, it is not my business. However the notion that dyneema is risky in the use of back stays and halyards is totally without foundation, unless the yacht is not properly set up. We have no visible wear on our dyneema other than some light fraying on our tapered spinnaker sheets that rub through the beak of the pole end, but the same tapered lines still go on for years in that use.

Oh yeah for sure the sheave damage was caused by the previous 1x19 wire.  I guess all I'm saying is that if you're considering switching, inspect everything carefully to make sure you have no sharp edges  :-)