Chafe on Reefing lines

[2Wind]

Last weekend I was sailing deep down wind in fresh conditions of 25-30kts. After 10 hours my near new 12mm double braid 1st reefing line blew out seemingly due to unrecognized chafe at the boom end sheave.

It's a heavily roached fully battened main with slab reefing (luff cringle manually tied off to the gooseneck and the leach via a block attached by webbing through which the reefing line runs).

I have only recently had new sheaves made for the boom end as the older ones were a little undersized diameter wise such that the sheave now sits only 1-2mm below the slot in the boom end with the aim of avoiding any contact between the line and the metal slot. Still, given the location of the break and chafe, it appears this is where the problem lies.

I'm thinking that I should have firstly manually tied off the reefing point on the leach to the boom with a separate line both as a safety in the event of a broken reefing line but also to bear some of the load by easing the reefing line and using it more as an outhaul and potentially reducing the potential for chafe.

10 hours seems pretty short so I need to think this through and find a better solution.

Any thoughts?

[estarzinger]

That's really fast to chafe thru a new 12mm line.

There's a serious problem somewhere - sharp or rough edge or surface. Should not be too hard to find because it has to be bad.

Bare dyneema is actually best for this line but even if you switch you should still track down this chafe point.

[s/v Beth]

I switched my reef point inside the boom one year ago, I am reversing my decision as the dyneema is already showing wear. A blowout in 35 knots plus is something I do not want to deal with.

[2Wind]

Sorry, i've just been off shore for a few days. I appreciate your comments.
Questions:
1. In regard to dyeema, I take it that you have a dyeema end spliced on to spectra or polyester double braid? Dyeema for the full 100 odd metres for 3 reefing lines will break the bank!
2. Given i appear to be chaffing at the boom end sheave due to back and forth lateral movement, the question as to how fully do you pull the reef point at the leech (in my case the block). Do you haul the reefing point right in so that there is very little vertical height from the boom, or do you still let it sit up a little higher, say 30-60cm. This alters the angle and forces at the sheave. I suspect i am under doing it.

Will look into getting dyeema ends spliced on to the lines.

Cheers.

[Jman]

Originally Posted by 2Wind

Sorry, i've just been off shore for a few days. I appreciate your comments.
Questions:
1. In regard to dyeema, I take it that you have a dyeema end spliced on to spectra or polyester double braid? Dyeema for the full 100 odd metres for 3 reefing lines will break the bank!
2. Given i appear to be chaffing at the boom end sheave due to back and forth lateral movement, the question as to how fully do you pull the reef point at the leech (in my case the block). Do you haul the reefing point right in so that there is very little vertical height from the boom, or do you still let it sit up a little higher, say 30-60cm. This alters the angle and forces at the sheave. I suspect i am under doing it.

Will look into getting dyeema ends spliced on to the lines.

Cheers.

Try taking the line from the end of the boom, through the cringle, and then tie it around boom directly under the cringle. The will pull the main tight to the boom and reduce the lateral movement.


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[neilpride]

The Zspar and Sparcraft boom series on Lagoons have a defective finish on the boom end tips aka the sheaves box, best thing you can do is to take a file and smooth the bits of metal where the line chafe ,, is a matter of final quality finish , they dont smooth those points inside of the box, instead they leave it rough from the mould... from La coruna to Las Palmas ,Canarias islands i broke 2 reef lines in a brand new lagoon 38, dont waste your money in brand new Dyna or spectra , found the point where the rope chafe ....Cheers.

[2Wind]

Thanks. I will in future haul the leech cringle/block in close to the boom at make the line angle to the boom end sheave more horizontal and reduce lateral movement.

NP: i see what you mean. I oversized the new sheaves so that their shoulders were only 2-3 mm inside the sheave box. But i'm guessing its still rubbing on the unfinished alloy edge esp if i under haul in the reef. Will address . Also will put R1andR2 thru the inside two of four sheaves to keep axis more central.

Now for some filing. Better still, i'll use the dremmel.

[Paul Elliott]

Originally Posted by 2Wind

Now for some filing. Better still, i'll use the dremmel.

Start with a file or Dremel tool, but finish with very fine emery cloth. If it's not glass-smooth and gradually-rounded then you will still have chafe.

[roverhi]

You've got somthing sharp cutting the line. We sailed 5,000 or more miles with a reef or two in the main and the only chafe was at the clew cringle. Just shortened the line a few inches and that was never a problem.