Deadeyes for dyneema rig tension?

[Éric Bouvéron]

Bonjour,
Did some of you tried to use deadeyes to tension Dyneema shrouds on a Tiki 21 ?
I tried to make some out of plywood, three layers of 6mm and glued with epoxy, but I am a little concerned about the tension they can hold.
Is there an alternative to plywood deadeyes for such small boats? What do you use on your own shrouds?
With thanks and regards,
Éric

[Ricardo Aráoz]

I don't think that'll do. Ply is not too strong in the edge (sorry, my english is not enough to express this properly).

I'd use hardwood, can you get lignum vitae? Or locust? Oak, ironwood or greenheart should also work.

Remember the grain direction should be at right angles to the pull of the lanyard, and you should immerse them in a bucket of oil for at least a year.

Cheers

[boatsmith]

http://www.colligomarine.com/shop-all/terminator-11-13mm-black these are commercially available, they are very nice, and Colligo is very proud of them (not in expensive. the friction on the deadeye lashings is considerable. I would recommend testing your plywoos ones. I think the epoxy joints are strong enough but i worry about the plywood glue lines. If you decide the plywood deadeyes are atrong enough then I would coat the lashing line reliefs and holes with epoxy with graphite additive  and sand them nice and smooth.

 Personally I really like the Colligo products, they are really nicely engineered and crafted.

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[Roger]

What about these? Low friction rings - Antal make them up to 38mm ID.

[boatsmith]

these rings might work on a Tiki 21. with larger loads the deadeye lashings tend to over ride and inhibit even lashing tension.

This being said JWD has used plain shackles for deadeyes on some of their designs IIRC

[Éric Bouvéron]

Thank you for your answers.
Ricardo, your English is certainly better than mine. But one year in the bucket is more than the time I spent to make the boat... However I took note of the wood you recommend.
Boatsmith, I didn't knew about Colligo marine, but heard about Precourt. The problem is that they both work on big sizes, not suitable (I think) for a small Tiki. http://www.uqtr.ca/~precourt/deadeyes/ventedeadeye.htm
I agree, excellent engeenering, but I think far too big for a Tiki21, and the price is high, even if I understand the quality of the products. Now if plywood glue lines are an issue, I may try to find some hardwood, teak or something alike, as Ricardo suggests, and redo them, as I did with the plywood, in three layers glued with epoxy. The three layers make the rounding of the lashing easy to shape.
Roger, I do not understand how this ring works or how to use it? On the deadeyes, the three lashing turns block the tension, but I do not know how this simple ring can do it?.
Anyway, thanks again, I will think on that for I like this way to work on a Dyneema rig.

[Omar M. Rashash]

While lignum vitae is the traditional material, it is difficult to find in adequate size and quantity. If you want to make your own deadeyes, 1/2"-3/4" industrial grade phenolic (resin impregnated linen), will do the trick. It can be worked with most woodworking tools and is between hardwood and aluminum in its difficulty to shape.

Omar

[Blanc Jean-Paul]

Bonjour,

De retour je suppose. ta question est de savoir si les cap de moutons en CP sont suffisants? Comme l'a dis Ricardo non. 

Pour ma part, j'ai simplement utilisé des cosse cœur en inox dans lesquelles j'ai fait trois passages de garcette de 6 mm en textile ordinaire. Pour infos, mes haubans sont en vectran de 6 mm, largement suffisant. La performance du vectran ou du dyneema  pour son diamètre est telle, que le risque est de cisailler les caps de moutons comme avec un fil à couper le beurre. (ça m'est arrivé avec les cales en haut du mât). Bien fourrer pour augmenter le diamètre au niveau de l’œil pour avoir une surface de contact plus grande.  

[boatsmith]

3-6mm deadeyes these are smaller with 11,000 lb breaking strength $34. G3 is also a very strong phenolic glass material that is strong stable and relatively cheap and machines well. I thought that Precourt ceased operations several years ago. Their website was last updated in '02. Here are their thoughts on shackle/ring used for deadeyes.

The original way to go with synthetic lines was by using splice and sailmaker's welded thimble on the two ends of the shrouds.  A bow shackle is pinned on the hull chaine plate. Then,  some wraps of thin line are lashed  between the shrouds and the bow shackle.  In the result, it works but there is some problems like :

• Difficulties to adjust the shroud length caused by a lot of frictions in the lashing ;
• A really small radius for the lashing lines ;
• The forces are not well distributed on the bow shackle's pin ;
• The thimble collapses under the forces involved, when racing really hard.

At $70 a pair the Colligo deadeyes are cheaper than I can machine them from any material and are very nice. I can't even glue up wood blocks and rout/rasp/epoxy/finish them for that price. I do have to count my time. The anodized aluminum ones will never rot or need refinishing. If all you want is to spend no cash and you don't mind spending lot's of time then by all means you can make some strong enough ones. Have fun.

[Robert Hughes]

Phenolic resin impregnated linen is a very good and well tested material.  It's sold in England under the name 'Tufnol'.  It was used for many years for blocks for running rigging and things like cleats.  You can still get them from stockists that specialise in the 'traditional' look.  I've replaced my old alloy mooring cleats with tufnol ones.

Tufnol doesn't corrode or degrade significantly, but the surface weathers nicely with age rather like teak does.  If you buy the right grade the water resistance is fine for fittings on deck.  I find it easy enough to work or machine as an amateur, but the smell if it gets too hot while you're machining it isn't pleasant.  Router, small lathe or bandsaw works fine. I've not tried glueing it.

The material is reasonably priced but fittings are expensive because of the work involved in manufacturing them.  You can often buy small bits of tufnol at boat jumble sales.

Omar M. Rashash said:

While lignum vitae is the traditional material, it is difficult to find in adequate size and quantity. If you want to make your own deadeyes, 1/2"-3/4" industrial grade phenolic (resin impregnated linen), will do the trick. It can be worked with most woodworking tools and is between hardwood and aluminum in its difficulty to shape.

Omar

[agur paesüld]

If you would like a fancy stuff for your dyneema lines, here is one small Estonian company offering various rigging eyes, including deadeyes: http://ropeye.com/products.html

If Im not mistaken, guy who invented those designs, tested them on his Mini Transat boat - http://www.classemini.com/?mode=skippers&id_skipper=432&lan...

cheers,

Agur

[Éric Bouvéron]

Thank you for your answers.
I will keep it simple, and go for Colligo.
However, speaking about phénolic resin, Tufnol,I have collected quite a few blocks that will find a place on my boat, once I -hopefully- put it in the water. I never tried to work with the bare product but I will remember that it is possible.
Thank you again,
Éric

[paul anderson]

This may be of interest.http://www.alden347.com/Blog/Entries/2015/12/30_Second_load_test_of...