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Jules

Best Line For Micro Block Eyes

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What line would be good for making eyes on micro blocks like this?

Harken-Micro-Block-Single_1.jpg.cafaf508798834a6b3d4cfa85b32b95e.jpg

It will be for lazy jacks.  The line size will be 1/4" or maybe 3/16". 

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I used 1/8" dyneema for my jacks. Lightweight, slippery, no stretch, easy to splice, not spendy at that diameter.

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19 minutes ago, IStream said:

I used 1/8" dyneema for my jacks. Lightweight, slippery, no stretch, easy to splice, not spendy at that diameter.

With Dyneema, from what I've seen, you have to be able to thread through both ends to make the splice.  There will be parts of it where an eye will already have been made on the other end.  That would mean the micro block and eye would have to be threaded through. 

Never worked with Dyneema.  Maybe this is possible?

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You can bury the dyneema without the brummel (threading) aspect, you just bury a longer tail. A good whipping will help as well. 
 

 

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11 minutes ago, Jules said:

With Dyneema, from what I've seen, you have to be able to thread through both ends to make the splice.  There will be parts of it where an eye will already have been made on the other end.  That would mean the micro block and eye would have to be threaded through. 

Never worked with Dyneema.  Maybe this is possible?

It's really not a big deal to make a standard eye even if the other end is fixed, you just bury the tail. I use about 70 diameters, which is about 9" for 1/8" line. Take the bury in through a gap in the 12 strands to make the eye, pull it out of the line about a foot below the eye (you've got to open up the weave so the foot of line scrunches up to less than 9"), taper the tail, and unscrunch the line to re-bury the tail. If you want, you can put a stitch or two into the neck of the eye to keep the bury from pulling out if the line flogs without any tension but lazy jacks are almost always under a little tension so I've found it unnecessary. 

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16 minutes ago, Dacron said:

It is possible!

I just finished sewing up the two halves of a sail pack and I'm feeling pretty good about it.  Then I see these wizards performing their magic and it takes the wind your of your sails.

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I don't see the difficulty.  Make a normal eye splice in the Spectra, using whatever method you prefer, although the McDonald brummel splice is preferred. 

Just make the eye a little longer, feed it through the bail on the block, pull it over the block body, and you have a dog hitch on the bail.  Just like you do to attach halyard shackles.

I learned that one in Italy in the late 80s, when we'd take the snapshackles off the halyards at night to prevent them being nicked.

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18 minutes ago, IStream said:

It's really not a big deal to make a standard eye even if the other end is fixed, you just bury the tail. I use about 70 diameters, which is about 9" for 1/8" line. Take the bury in through a gap in the 12 strands to make the eye, pull it out of the line about a foot below the eye (you've got to open up the weave so the foot of line scrunches up to less than 9"), taper the tail, and unscrunch the line to re-bury the tail. If you want, you can put a stitch or two into the neck of the eye to keep the bury from pulling out if the line flogs without any tension but lazy jacks are almost always under a little tension so I've found it unnecessary. 

Here's their version of what I described:

 

I don't taper it first because I find that it makes it harder to bury it cleanly and I use 70 diameters bury to buy myself some fudge factor as there's no strength penalty for extra bury but there's a big penalty for too little. No wizardry required...

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Do lazy jacks really need blocks? If you use a slippery rope or a nylon thimble you don't have a block that will end up banging against your mast (it just will). There is so little friction on these lines and you will not lift anything up on a lazy jack.

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I used stainless steel rings but you still want small standard blocks under the spreaders or cheek blocks on the mast to make the heavily loaded and tight turn of the main jackline down the mast to the cleats below.

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7 hours ago, AnotherSailor said:

Do lazy jacks really need blocks? If you use a slippery rope or a nylon thimble you don't have a block that will end up banging against your mast (it just will). There is so little friction on these lines and you will not lift anything up on a lazy jack.

I would have used thimbles but I already had the micro blocks.  They won't be anywhere near the mast, so banging won't be a problem.  And with the lines holding up a sail pack, they will always be under some tension.  The micro blocks should work okay.

7 hours ago, IStream said:

I used stainless steel rings but you still want small standard blocks under the spreaders or cheek blocks on the mast to make the heavily loaded and tight turn of the main jackline down the mast to the cleats below.

There are already blocks up on the mast on mine.  The original setup has the line coming down off the mast block running down to the boom, about 2 feet off the mast, and then to cam cleats on the forward section of the boom.  There are 3 points of attachment on the boom. 

With the sail pack, there will be 4 points of attachment, which leaves the lines from the top mast block running down the sides of the mast, so I'll need to install a couple cleats on the mast.

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10 hours ago, Dacron said:

It is possible!

BINGO

I was about to try and type out a verbal description of this, but this video is much better. It's like a magic trick.

I have not had good luck with the "make the buried tail longer" method of splicing dyneema. It's just too slippery. OTOH it's very easy to sew thru the braid then whip over that. For good luck I add a drop of superglue on the whipping.

Another note- don't splice an eye thru hardware. Make the eye slightly larger and luggage-tag it.

FB- Doug

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11 hours ago, Jules said:

What line would be good for making eyes on micro blocks like this?

Harken-Micro-Block-Single_1.jpg.cafaf508798834a6b3d4cfa85b32b95e.jpg

It will be for lazy jacks.  The line size will be 1/4" or maybe 3/16". 

Very thin lines on lazy jacks are a sail chafe problem and difficult to grip with your hands 

a common polyester single braid works fine 

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There's an argument that you shouldn't stitch through the Dyneema to hold a long-bury splice as this splits the fibres and creates a point load. Instead use a stitchless whipping just to constrict the point below the eye where the bury starts to hold it place and prevent it from opening when not under load....

https://www.animatedknots.com/common-whipping-knot

As a splicing/knot resource this website is great - step by step pictures rather than videos which I found way more user friendly

https://www.animatedknots.com/brummel-eye-splice-knot 

 

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I converted a boat to thin dyneema and ronstan shocks for the in the air lazy jack gear.  The hoisting lines were lead through small harken cheek blocks at the mast and went to cleats near the gooseneck and were made with 1/4" double braid for handling and cleating.  The lazy jacks were pulled forward to horns on the gooseneck for storage when sailing and deployed only when the sail was lowered.  Worked very well and no chafe issues when sailing.  Everything ran much smoother with the thin dyneema.

I like the Samson recommended lock stitching for long-bury splices - they practically disappear and are loose enough that there shouldn't be much if any point loading.  I'm sure Samson verified their lock-stitch method after extensive testing.

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You can always splice it all up w/o the block then luggage tag the block on one end.

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14 hours ago, IStream said:

Here's their version of what I described:

 

 

in this splice , why wouldn't you lead the tail through the line like the start of a brummel and then bury the tail...  ie. you make the eye by leading the tail through the like and bury at that point.. wouldn't that lock the eye in better?

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You could, but it's already 10X overkill for jacks.

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15 hours ago, Jules said:

With Dyneema, from what I've seen, you have to be able to thread through both ends to make the splice.  There will be parts of it where an eye will already have been made on the other end.  That would mean the micro block and eye would have to be threaded through. 

Never worked with Dyneema.  Maybe this is possible?

There are a couple of fairly easy techniques for making a brummel eye in dyneema when the other end isn't accessible. You should be able to find a good YouTube with step-by step instructions.

Or you can make a straight bury eye and throw a couple of stiches and/or a whipping on it and it will be plenty strong. I've heard that a straight bury eye is actually stronger than a brummel, as long as you secure it so it can't come loose. But it doesn't seem like maximum strength would be as important for lazy jacks.

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3 minutes ago, TJSoCal said:

There are a couple of fairly easy techniques for making a brummel eye in dyneema when the other end isn't accessible. You should be able to find a good YouTube with step-by step instructions.

Or you can make a straight bury eye and throw a couple of stiches and/or a whipping on it and it will be plenty strong. I've heard that a straight bury eye is actually stronger than a brummel, as long as you secure it so it can't come loose. But it doesn't seem like maximum strength would be as important for lazy jacks.

Yes 

 

the Brummell concentrates  load and is fiddly to perform 

only use the Brummell in special situations 

 

snatch and torque loads

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10 hours ago, Steam Flyer said:

BINGO

I was about to try and type out a verbal description of this, but this video is much better. It's like a magic trick.

I have not had good luck with the "make the buried tail longer" method of splicing dyneema. It's just too slippery. OTOH it's very easy to sew thru the braid then whip over that. For good luck I add a drop of superglue on the whipping.

Another note- don't splice an eye thru hardware. Make the eye slightly larger and luggage-tag it.

FB- Doug

We use the locked brummel splice to anchor stuff in 5000m of water. Never had a splice fail yet. Once you've done a few it's pretty straightforward.

Nobody is going to pull 500m of rope through to do a splice so the single-end method is the only way to go IMO.

I still have a couple of 500m shots of dyneema left over from a mooring recovery in the Southern Ocean. Might re-rig my boat with it one of these days. It's well pre-stretched :)

FKT

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Nothing to add to the comments above, but I have been converted away from such blocks in that size range to shock blocks - no moving parts, higher load rating.

Ronstan Shock Block Sheaveless Pulley - kite22knots

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7 hours ago, ALL@SEA said:

Nothing to add to the comments above, but I have been converted away from such blocks in that size range to shock blocks - no moving parts, higher load rating.

Ronstan Shock Block Sheaveless Pulley - kite22knots

Fashion and marketing are interesting things. Once we all knew we had to have the fanciest bearings in everything, now no moving parts and a high load rating are the answer to everything. At each step they manage to crank the price for the latest revolutionary leap.

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9 hours ago, European Bloke said:

Fashion and marketing are interesting things. Once we all knew we had to have the fanciest bearings in everything, now no moving parts and a high load rating are the answer to everything. At each step they manage to crank the price for the latest revolutionary leap.

Yep, definitely need those high load ratings for lazy jacks! 

I stand by my earlier comment to just use a nylon thimble, or if you use dyneema: it is so slippery, it will move without much friction. Those metal blocks will at some point hit the mast, even if designed to be away from the mast, it will happen. wait for it.

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No blocks needed with Dyneema or if you insist on using blocks then just splice a luggage tag on both ends. Problem solved! 

Or you can use 4-6mm Double braid polyester and standard eye splice.

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the load on lazy jacks is pretty low...what I did with mine on my S2 11.0 is I simply whipped an eye from cored yacht braid 6mm ish....typical control line stuff...

 

 

 

 

eye_whip.jpeg

 

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6 hours ago, AnotherSailor said:

Yep, definitely need those high load ratings for lazy jacks! 

I stand by my earlier comment to just use a nylon thimble, or if you use dyneema: it is so slippery, it will move without much friction. Those metal blocks will at some point hit the mast, even if designed to be away from the mast, it will happen. wait for it.

Sorry, didn't notice the bit under the photo regarding the purpose of lazy jacks... I agree with what Flip said above.

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18 hours ago, ALL@SEA said:

Yep, definitely need those high load ratings for lazy jacks!

Oh yah! I need the dyneema on my lazy jacks because the crew is usually all jumping up and down on the boom when I let loose the main halyard...we crank the mainsail until a few inches disappears well into the  masthead and jams up the main sheave. I gave up on headboards long ago, they keep you from getting the main racin' tight!

...so as they are trying to free the halyard, the lazy jacks stop the 1200 pounds of humans from hitting the deck with the boom when it lets loose...so many crew got injured before I came up with that...we broke a lot of lazy jacks...because we race hard, real hard.

lol

 

 

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On 10/15/2020 at 1:20 PM, AnotherSailor said:

Yep, definitely need those high load ratings for lazy jacks! 

Good point!  I think I'll switch to Harken's 200mm stainless steel teardrop block.  It can handle a 1" line easily and has a maximum working load of 50,715 lbs.  That should hold.  And they look really cool!  But I may have to beef up the mast a bit.

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20 hours ago, EvaOdland said:

Oh yah! I need the dyneema on my lazy jacks because the crew is usually all jumping up and down on the boom when I let loose the main halyard...we crank the mainsail until a few inches disappears well into the  masthead and jams up the main sheave. I gave up on headboards long ago, they keep you from getting the main racin' tight!

...so as they are trying to free the halyard, the lazy jacks stop the 1200 pounds of humans from hitting the deck with the boom when it lets loose...so many crew got injured before I came up with that...we broke a lot of lazy jacks...because we race hard, real hard.

lol

 

 

They'll pull the fucking spreaders off next. I'd rather break the lazy jacks and bruise the apes. Never ceases to amaze me what a racing crew can fuck up. Individually most of them aren't that stupid, but in a group...

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