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unbusted67 · 01-05-2020, 16:10

Is it possible to lash a thimble into an eye without splicing? If so what would be the method?

Dsanduril · 01-05-2020, 16:19

It is possible, it's called seizing.

The "typical" is a round seizing as shown above and here:

Then there's the "racking" seizing:

thinwater · 01-05-2020, 16:29

The more practical method for most applications is sewing. Sailmakers do it all the time. Industrial climbing rope eyes are generally sewn. But there are formulas.

There are a number of methods. In general, it will be 50-100% stronger than a seized eye in synthetic material (traditional materials are different) and far more compact. Chafe protection is important withe seizings and sewn eyes.

What is the application?

Sail Delmarva: Sewn Eye Splices

I've tested this lots:

Dsanduril · 01-05-2020, 16:32

Yes, the slipperier the material the worse the seizing. Old-time hemp had a lot of friction with the marline, modern Dyneema very little.

I've used a racking seizing with Dacron/polyester quite successfully. Never tried it with Nylon, and Dyneema and other 12-strand stuff is so easy to splice and unsplice that I've never felt the need.

unbusted67 · 01-05-2020, 17:07

Quote:

Originally Posted by thinwater

The more practical method for most applications is sewing. Sailmakers do it all the time. Industrial climbing rope eyes are generally sewn. But there are formulas.

There are a number of methods. In general, it will be 50-100% stronger than a seized eye in synthetic material (traditional materials are different) and far more compact. Chafe protection is important withe seizings and sewn eyes.

What is the application?

Sail Delmarva: Sewn Eye Splices

I've tested this lots:

Wanting to put an eye mid jib sheet on a single sheet. I’ve got some really skinny dyneema lashing that i might even be able to stitch into the sheet. But also might just some seizing.

Just read your article and it sounds like dyneema might not be the best option.

thinwater · 01-05-2020, 20:49

Quote:

Originally Posted by Dsanduril

Yes, the slipperier the material the worse the seizing. Old-time hemp had a lot of friction with the marline, modern Dyneema very little.

I've used a racking seizing with Dacron/polyester quite successfully. Never tried it with Nylon, and Dyneema and other 12-strand stuff is so easy to splice and unsplice that I've never felt the need.

The problem with nylon is that it gets skinny when it stretches and the seizing get loose. This happens by 30% BS at most.

What was the % breaking strength of your seized eyes?

thinwater · 01-05-2020, 20:51

Quote:

Originally Posted by unbusted67

Wanting to put an eye mid jib sheet on a single sheet. I’ve got some really skinny dyneema lashing that i might even be able to stitch into the sheet. But also might just some seizing.

Just read your article and it sounds like dyneema might not be the best option.

I'm not visualizing it. Do you mean attach the clew to the center of a sheet? If that is the question, use a lark's head.

**Jim Cate** · 01-05-2020, 21:42

I've successfully used a combination of stitching followed by seizing... a belts + suspenders approach. It's pretty quick to do, hasn't failed me yet, and can easily be done on used rope, where splicing is difficult or impossible (double braid construction).

I will admit to not trusting it for critical applications!

Jim

Dsanduril · 02-05-2020, 07:41

Quote:

Originally Posted by thinwater

What was the % breaking strength of your seized eyes?

I can only say "strong enough". I won't even remotely dispute you that a stitched eye is likely stronger in most cases in modern material. The passion, skill, and knowledge that you, SWL, and Evan bring to this forum around ropework are very much appreciated and the testing information you guys publish is nothing short of amazing. I learn from it every time, and that's how I now know Brummel splices, and tying soft shackles, and any number of other very cool techniques. But when someone asks the question the OP did my mind immediately goes back to the old-school things I learned long ago rather than the newer things.

Now, with more detail, I'd ask why you want a thimble bashing around when the sail is flogging (the sail never flogs, right

)? I've done everything I can to remove any hard bits at the clew of the sail. Lark's head, soft shackle, there are several options for getting a continuous sheet attached that don't require a bit of hard stuff up there.

thinwater · 02-05-2020, 07:52

Although I admit to using siezine over stiching when doing a sailmaker's eye, it is NOT belt and suspenders. The siezing holds the eye closed and keeps the tail from pealing, but it adds no strength.

The reason is like reinforcing a steel anchor chain with a nylon rope. The chain is stiff so the rope does not take any load until the chain snaps. Same with stitching and seizing. The stitching is very stiff and takes load immediately, but the seizing cannot take load until the line compresses and shifts enough to place the seizing at an angle. For the seizing to carry load it needs to be applied with brutal tension, something few of us are able to accomplish. I've letterally been able to slide tight seizings off a rope with my fingers that was also stitched and placed under high load; even polyester gets skinnier when loaded to >30% BS and the seizings become loose. It was a surprise the first time I was it.

Seizing is a good thing if applied for the right reasons; throat spread and holding the tail down. Then apply a chafe cover.

[genoa sheets--the working load is about 1500 pounds)

Dsanduril · 02-05-2020, 08:23

The way I was taught, oh so long ago, was to use three seizings as shown in the first photo. The most critical is the middle seizing.

First make the eye with the throat seizing.

Then make a temporary end seizing on the tail. Apply significant tension to both the tail and the standing part of the line.

Apply the middle seizing to the line that is stretched.

Remove the tension, remove the temporary end seizing, apply the tail seizing.

Still have a serving mallet aboard that was used for some of that work. It doesn't roll as nicely as it does when serving a round cable, but it still suffices to put a lot of tension on the seizing line.

thinwater · 02-05-2020, 09:40

Quote:

Originally Posted by Dsanduril

The way I was taught, oh so long ago, was to use three seizings as shown in the first photo. The most critical is the middle seizing.

First make the eye with the throat seizing.

Then make a temporary end seizing on the tail. Apply significant tension to both the tail and the standing part of the line.

Apply the middle seizing to the line that is stretched.

Remove the tension, remove the temporary end seizing, apply the tail seizing.

Still have a serving mallet aboard that was used for some of that work. It doesn't roll as nicely as it does when serving a round cable, but it still suffices to put a lot of tension on the seizing line.

Yes, that helps. Of course, the standing part of the middle seizing was not tensioned. Yes, you need a serving mallet, which is not easy to swing around the rope when rope is tensioned between winches. It's a long process.

I think the critical evidence is that 100% of safety-related eyes are sewn. I've had several people (professional riggers) make up seized eyes for testing, none passed 65% breaking strength, and they were variable. Sewn eyes can be reliably made to 90-95 rated strength in minutes. They pass drop tests. They are far more compact. Seized eyes look salty, but like a sextant, are obsolete.

And a seized eye in nylon is practically impossible, even with the above procedure. Nylon stretches too much, which means the line shrinks and the strength must all be within 2 inches (the reason is related to stretch--the US military researched with for chutes 80 years ago).

Dsanduril · 02-05-2020, 10:25

I agree that the sewn approach is probably the right one >95% of the time based on your testing and on other things I've seen. So the discussion is mostly moot. Certainly in the marketplace sewing is the omnipresent style, although that in itself doesn't mean anything, could just be cheaper/easier/faster/better quality control - its the comparison testing that makes the difference.

Where I first applied/used a seizing (with modern materials) was on a boat that had single-braid polyester running rigging. That line is non-spliceable, and actually pretty hard to sew except possibly when brand new. But from a construction perspective is reasonably well suited to seizing. It's a very hard-laid line with little air/excess volume. It's also not used much any more except in small sizes.

Double braid has a lot of constructional deformation when load is first applied because it tends to be supplied that way. Makes it very hard to get a tight seizing, especially on new line. You also have the issues of core movement even if the cover doesn't move, that all depends on the tightness of the constriction you've applied with a seizing. Sewing removes that variable since it locks core and cover together.

**Jim Cate** · 02-05-2020, 17:20

Thin, could you show us what the approved stitching pattern is for making sewn splices? I've just cobbled mine up with no known plan (and they have worked) but I'm sure there is a best practice kinda thing to be aimed at. I'm interested in both machine and hand stitching ideas.

Thanks,

Jim