Securing Ring To Spar: Knot(s)?

[PeteCress]

I have a series of rings secured to a boom. Their function is to keep the mainsheet from flopping around.

There is little or no stress on the rings, and minimal forces trying to slide them back-and-forth on the boom.

I'm throwing a clove hitch around the boom, tying it off with a square knot, they tying the ring on with a second square knot and putting a half hitch in each end of the line to keep the second square knot from coming undone.

viz: [img]http://lh4.googleusercontent.com/-hX...0/IMG_0185.JPG[/img]

It works, but I figure there's a "right' way to do this that doesn't look so ugly.

??

[Peerie Maa]

I'd recommend a square lashing with some light line:

[MiddleAgesMan]

Slip the ring onto a loop of small line large enough to pass around the boom plus a little more. If neatness counts splice the line so the ring can slide freely around the loop. Pass one end of the loop over and around the boom. then pass the ring through the end of the loop and cinch up. It looks clean and is pretty simple to do. Experiment with the size of the loop before you do the splicing so you know how big the spliced loop needs to be.

[David G]

I believe what MAM is recommending is a Cow Hitch... which is how I'd go as well.

[Peerie Maa]

I believe what MAM is recommending is a Cow Hitch... which is how I'd go as well.

That depends on whether Mr Cress wants the ring snug to the spar, or hanging a ring diameter below it. A cow hitch is certainly easy to adjust or take off.

[Arizona Bay]

...or maybe a Prusik knot, which won't slide along the boom.

http://fmg-www.cs.ucla.edu/geoff/prusik_knot.html

[davhill]

I'd use a series of running clove hitches, with the ring sandwiched between the, er, cloves: Turn the first loop of the clove hitch, thread the ring on, then turn the second loop... so the ring is hung in the 'crossover' of the clove hitch. Run the line <whatever spacing you are usin along the spar, and repeat for the next ring, &etc from end to end. Secure the extremities with a triple clove and a half-hitch to lock the tail. This is neat and compact, dead-simple, and maintains the ring spacing. You could use black nylon line to blend with your spar. Terminate the ends with a turks-head if you want to get really crazy.
-dave

[Gib Etheridge]

Here's a nice way to do it if you want to switch to thimbles instead of rings. Loosely seize the thimble to the boom then wrap (frap) the space between the two to tighten it up. This pic from an old WBForum thread.

[PeteCress]

That depends on whether Mr Cress wants the ring snug to the spar, or hanging a ring diameter below it.

Mr Cress left that part out when he was thinking through the requirements.

The rings need tb variable distances from the boom.

Here's a pic of the rings in non-optimal position.
[img]http://lh4.googleusercontent.com/-tv...20Lakes.05.jpg[/img]
Non-optimal bc stress from the sheet is bearing on rings. It's not exactly a religious issue.... but it's pretty clear to me that I do not want the rings bound directly to the spar bco the needless stress/wear/friction.

Reason: the main sheet is running from a block on the aft end of the boom to a block on the fore end of the boom. Since the sheet will be under tension most of the time and the ring's only function is to keep it from getting out of control when it's loose, the centers of the rings have to line up with the path of the sheet when it is under tension - so it does not bear on any of the rings.

[PeteCress]

...or maybe a Prusik knot, which won't slide along the boom.

http://fmg-www.cs.ucla.edu/geoff/prusik_knot.html

I was liking the simplicity of MiddleAgeMan's cow hitch/lark's head until you suggested Prusik.

I'm going to try Prusik's when I take it out tomorrow - figuring that the lark's head would be prone to slippage but the Prusik could get around that while keeping the same simplicity and easy adjustability.

[PeteCress]

I was liking the simplicity of MiddleAgeMan's cow hitch/lark's head until you suggested Prusik.

I'm going to try Prusik's when I take it out tomorrow - figuring that the lark's head would be prone to slippage but the Prusik could get around that while keeping the same simplicity and easy adjustability.

Turned out lark's head/cow hitch was just fine. Reason: there's no slippage issue bc the line that spirals around the boom holding the sail on constrains the rings from sliding more than the distance between grommets on the sail.

[J. Dillon]

Not quite same problem, but bulk seems to be the answer here.

JD

[wizbang 13]

wrap it and frap it

[Thorne]

I was lucky enough to find a small bronze block that fit a bronze pad-eye, which works well for my mainsheet along the boom. Since it isn't load-bearing, it doesn't pull out the short screws attaching pad eye to boom.

[Ben Fuller]

I guess I might have given rings a pass and just knotted a loop of light line around the boom. Kind of what we used to do racing Sunfish, although there we used plastic electrical ties.

[Dusty Yevsky]

Do like the iceboaters and install several fairleads on the bottom of the boom. Neat, clean and simple. Make your own if you don't like plastic or if the boom is rounded.