Nacra 5.0 Diamond Wire Safety Wire

It's very important to have the diamond stays secured to the ends of the spreader, but I don't think how that's done is critical. You're just preventing it from falling out of the groove when it's unloaded. The slightly smaller dia wire should be fine, with whatever pattern seems good. Make sure you tape the end well, or use spreader boots.

Dave

That diameter will work fine any type of stainless wire bigger than 22 ga is fine. Just wrap it around the diamond 4-5 times above the spreader go through the spreader and around the diamond 2-3 times then wrap another 4-5 times below the spreader. Take the 2 free ends and twist tie them together. Make sure everything stays snug while you to all this. Tuck and Tape up the sharp ends so that they don't scrape your sails. Voila.

Thanks Dave and Dave.

[del][/del]A

Edited by Edchris177 on Jul 27, 2015 - 07:19 AM.

A couple of years ago I was at the home of a gentleman in Malibu who used to build parts for Nacra, & had sailed/worked with Tom Rolland during his early years. He showed me a photo of them sea trialling the Nacra 36.
We were discussing diamond tension & prebend( he was showing me a carbon fibre mast with double diamonds that went with his 20' carbon hulls). He made the remark that it was suicide to affix the diamonds to the spreaders using the method shown in the early Nacra manuals,(a couple of wraps of seizing wire).
The diamonds/spreader make a very strong structure out of a flimsy stik, but, ONLY IF THE SPREADER DOESN'T MOVE. As soon as the spreader moves out of perpendicular,(either up or down the wire), the force wants to move them further out of plumb, & integrity of the mast is lost. He was adamant about wrapping tape, enough that you didn't need those plastic end caps, very tightly in a figure 8 round the spreader ends & diamond wires to prevent any movement on the wire. As he put it, "if you can slam your hand down on the spreader end, & move it, you risk losing the mast. All the seizing wire does is keep the wire from popping out of the slot, it's very poor at stopping movement."
Since that conversation, I have not used "seizing wire", or the plastic end caps. Use electrical tape,(not the black stuff, it leaves icky residue, get the colored, comes in white, red, or yellow) wrapped as described. You can buy 6 rolls for the cost of one end cap, an application last at least 2 years. Your hand will break before you can budge the spreader bar.
Here is a good thread on breaking a mast due to spreader bar moving.
http://www.thebeachcats.com/index.php?module=forums&func=viewtopic&topic=14793

Thanks Ed. Good info. for me. I have been concerned that if I damage my mast a replacement, 5.0 specific, would be hard to find. I wondered whether the basic extrusion from the other models was the same and according to the post you reference it is.

I should have added that because you have the older style, straight through the mast spreader bar, the seizing wire is fine. You have to bend the entire diameter of the bar to get it to move, so you are really only trying to keep the wire in the slot.
The newer style use the same diameter bar, but because the mast end uses a slot that pins to a fitting at the mast hound, it can be more prone to moving up/down.
However, if you wire it, you still have to secure a protective boot, or tape the crap out of it, so why not just tape it in the first place.