Plastic stopper balls: how tough?

Greenheart

Greenheart

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You've seen these coloured balls, handy for creating a rope-stopper that won't deform or jam in cleats as knots may...

0002292_bungee-ball-ties-rope-stoppers-various-sizescolours.jpeg


...and I've used plenty to keep line-ends visible and easy to grip.

But the other day in Force 4, I heard a weary father telling his infant daughter (who, walking along the aisle with him, had asked for the umpteenth time, "and what's this for, daddy?") that actually, these plastic balls aren't a good idea at all for the intended purpose, as they're inclined to shatter under load.

Has anybody ever known one to go pop? The purpose I'm putting them to, will prevent 3mm line being pulled through 15mm cringles. Bit hard to describe without a photo, but my weight will be dangling under four such cringles in a trapeze harness, with four x 22mm balls preventing the line slipping through, and me getting a wetting.

Are the balls to be trusted?
 
"life critical"?

Thanks Mainsail, but I mean a dinghy trapeze harness. It would be very inconvenient, and possibly comical if one burst under load, but I don't think I'd be in for an obituary.

I've just never seen one break, so I'm surprised to hear that it's even possible, unless it's determinedly abused to destruction.
 
Never seen one break. I have seen them used for preventing halyards from jamming in the sheaves up the mast and for preventing spinnaker guys from jamming in pole ends.

I've never seen one used for the application you are referring to.
 
Pretty sure they'll weaken with age. As said they are pretty damn tough though. I'm pretty sure I've seen them break but never under circumstances they were supposed to be exposed to.
 
Used them on the rope strop on my Hobie 17 trapeze, and at the nationals in South Shields in about 100 BC, I got unceremoniously dumped into the 'oggin by the ball disintegrating... bit hairy on a fast reach. Fortunately I managed to hang onto the mainsheet...
 
The ones I've had have been very tough.
They have their uses, but I think they should never be able to be stepped on or sat on.
And the elastic sail ties with them should be banned.
Like all plastics they may go bad with lots of UV?
I'm not sure they are all the same.
Some of them are almost sharp where the rope goes through.....
 
We used to call them parrel balls though I think that term originally applied to big wooden beads used on gaffers, I have used them behind spinnaker or guy ends also on halyards to separate the snap shackle from the rope and thus keep it from the pole or mast entry but never as a stopper in high load situations.
Just tried squeezing one in the vice, it was a softish plastic (pvc or upvc?) which crushed and deformed an awful lot before it split so I think they are fit for purpose.
 
Gladys said:
Used them on the rope strop on my trapeze, got dumped into the 'oggin by the ball disintegrating...
Click to expand...

Damn, up till then it was sounding like a good idea! :hopeless:

I'm hoping you're much heavier than me Gladys, and had all your weight tugging on one stopper, rather than divided four ways like mine.

But it's fair warning, appreciated. Thanks for all replies. :encouragement:
 
dancrane said:
"life critical"?

Thanks Mainsail, but I mean a dinghy trapeze harness. It would be very inconvenient, and possibly comical if one burst under load, but I don't think I'd be in for an obituary.

I've just never seen one break, so I'm surprised to hear that it's even possible, unless it's determinedly abused to destruction.
Click to expand...

Sorry, I misunderstood. For some reason I had an image of you using them on equipment to climb the mast.
Yes, I have used them on a dinghy trapeze but they do degrade over time in the sun.
 
I've used one for >10years on a main halyard that also holds up the cover when ashore. So its "exposed" 24/7 (although maybe not to UV as we don't seem to ever see the sun these days!). Its faded and I have noticed some surface cracks - its on the "next time I'm in a chandlery I should shell out 50p on a new one" list...

I use it like this:
TJmain.gif

Credit: Wayfarer-international.org

So I'm not sure how much load it gets. I certainly don't think its taking shock loads like a trapeze harness might...?

I also use them just as "pretty" stoppers on things - with some "colour logic"

Soft shackles are a similar principle without the lump of plastic, although not a bit of witchcraft I've yet played with.
 
Thanks to Quandary for doing the vice-test. :encouragement: And to others for UV advice.

ShinyShoe said:
There are keyball harness systems that appear to use them!
Click to expand...

That's very funny, Shiny...I'm actually using stopper-balls to attach an old Musto harness to a brand new Allen keyball connection.

My problem was that the steel spreader-bar doesn't connect easily with the harness's existing cringle-positions. There aren't any points on the spreader-bar through which the harness's original adjustment line could be fed to allow its original full adjustment...

...so I needed to connect each cringle tightly to the part of the bar closest behind, otherwise its position would twist out of shape.

The knots sticking out of tops of the stopper-balls, are neater than the photo suggests. Each short length of 3mm line runs through the stopper ball, through the cringle behind it, round the steel bar behind that, then back up through the same stopper-ball.

I haven't yet decided how to draw the left and right harness cringles closer together, to tighten round my waist. Each bit of stoppered 3mm line slides easily left and right along the spreader-bar. It's loose enough at present to enable climbing in and out, with the wetsuit on. I don't anticipate it needing to fit anyone else.

But I wonder whether the stopper-balls will be under unintended stress from the fact that in effect, two lines are passing through each one, pressing outward in opposite directions at the inside of the hole in the ball, rather than just downward through its base?

Enough words, take a look, if Photobucket permits. Restrain sniggers please:

20170824_101342_zpsuecvjidh.jpg
 
How about dispensing with the balls altogether?

On each side, use a single line. Cow hitch around one bar, then pass both ends up through the cringle. Tie a small bowline close to the cringle. Take the other end of the line down through the other cringle, once or twice around the bar then back up.

Take it to the bowline and do a round turn and two half hitches through the bight of the bowline. This will allow you to cinch the line quite tight.
 
That's a smart answer which I tried first, but the thimble aperture allowed the line to pull them over the top (and bottom) of the upper and lower spreader-bars. The stopper-balls effectively make the thimbles smaller so the shape of the harness is retained better.

Does anybody have a view on how tight a trapeze harness ought to be? I've just tried it with the wetsuit on, and the thimbles at the outside corners of the spreader-bar. I'm not sure I'd want it roped any tighter round my middle, unless there's an important reason to?
 
dancrane said:
Damn, up till then it was sounding like a good idea! :hopeless:

I'm hoping you're much heavier than me Gladys, and had all your weight tugging on one stopper, rather than divided four ways like mine.

But it's fair warning, appreciated. Thanks for all replies. :encouragement:
Click to expand...

I used to crew Five Oh's so yes, I'm a substantial individual, and it was a single ball... It had lasted more than a season though. Must have been a spectacular vision from other boats!
 
dancrane said:
That's a smart answer which I tried first, but the thimble aperture allowed the line to pull them over the top (and bottom) of the upper and lower spreader-bars. The stopper-balls effectively make the thimbles smaller so the shape of the harness is retained better.

Does anybody have a view on how tight a trapeze harness ought to be? I've just tried it with the wetsuit on, and the thimbles at the outside corners of the spreader-bar. I'm not sure I'd want it roped any tighter round my middle, unless there's an important reason to?
Click to expand...

If you can stand up straight on land before sailing, it is not tight enough.
 
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