450: Lagoon 450 Reefing lines Dyneema

[Darksyde]

Hi together

i am changing my reefing lines from regular 14 mm to 12 mm in Dyneema

Has anyone done this before

The running lines in 14mm are to huge in my opinion.

So 12 mm in Dyneema ( 7500 kg breaking load )should be ok ??

Any Experience ??

M

[Privilege]

12mm dyneema has a much greater breaking strain than the 7500kg you have suggested...it's somewhere in the region of 16,400kg.

When manufacturers provide dyneema sailing rope, it's often covered in polyester or a similar material to provide abrasion and UV resistance and to make it easier to use on a winch. The cover doesn't really offer any additional strength but it is factored when they measure the diameter. Therefore, a 12mm 'spectra rope' with a protective cover might actually be 7mm Dyneema SK75 Single Braid, or similar, which has a breaking strain of 7500kg.

So, to answer your question, 12mm dyneema will be plenty big enough, in fact it will likely be big enough to lift your boat out of the water. 12mm double braid, (with a 7mm dyneema core) will also be plenty big enough. If you look at the specs on the blocks and traveller which all come into play when reefing, they will be nowhere as strong as the 7500kg dyneema.

I hope this helps.

[Darksyde]

it is 7500 daN

and this is 7500 kg

[StuM]

Originally Posted by Darksyde

it is 7500 daN

and this is 7500 kg

Megatwin is 12 strand braided dyneema core with a polyester cover.

Privilege was almost correct - it's actually SK78

[Bean Counter]

We had 3 * 14mm poly braid reefing lines. The second reef chafed and broke, so we replaced it with old 12mm dyneema spinnaker halyard. It has no problem at all with the load, however if you get chafe on a covered dyneema line the cover will clump and not run through the system (which is what happened to us) so it is an expensive line to replace. We have since rectified the chafe problem and the still have the old 12mm covered dyneema as second reef (fortunately the chafe occurred on the line in a place so when I cut it off there was still sufficient length).

I don't know about using uncovered 12 mm Dyneema like Amsteel, it would probably slip through the system more easily and any chafe would not clump as much as a cover. Might not hold well if you use clutches. Expensive though.

[Darksyde]

Thank you Bean Counter

Thats what I want to hear

M

[waterman46]

I have to honestly ask, why use dyneema and not regular polyester braid? 12mm poly is certainly strong enough and got to be much cheaper. I never noticed stretch to be much issue in slab reefing, if thats the application.discussed. Yes it will wear and need to be shortened to move the wear point occasionally, but are the hi tech lines not subject to wear as well?

[Benz]

Originally Posted by waterman46

I have to honestly ask, why use dyneema and not regular polyester braid? 12mm poly is certainly strong enough and got to be much cheaper. I never noticed stretch to be much issue in slab reefing, if thats the application.discussed. Yes it will wear and need to be shortened to move the wear point occasionally, but are the hi tech lines not subject to wear as well?

Hi-tech lines chafe less, since they're tougher and more slippery. That's why anti-chafe sleeve is made from Dyneema.
But I've never encountered a 12mm dyneema-cored line where the core was only 7mm. Usually you subtract 2mm to get the core dimension. So, a 12mm line will have a 1cm core.
Although, being a modern sailor, I would subtract 1/32" from 1/2" and leave the metric system out of it. But that's just me.

[onavegador]

On my catamaran who had about the m2 mainsail as the Lagoon 45 I used 12mm Hercules from Liros. On the learning stage I found out that chafing occured if the reefing line was not really tightend. So I fitted the reefing eyes on the mainsail with blocks and tightend the reef lines very hard. So no more chafing occured I had only to replace them when arriving in Australia after a passage over the Falklands, Cape Hoorn and the Chilenean Channels (but then the cat was also in need of new shrouds).

[gatorsailor]

Darkside, Can you expand on your comment please "we rectified the chaffing problem?"

Thank you

[Darksyde]

Not yet.

Its winter here in the med

I will report when the new lines are mounted


M

[PaulinOz]

Just swapped out 1st and 2nd reef line from 14mm Double braid nylon to 12mm Spectra braid. Currently 3 rd reef line used as Out-haul on mainsail.

Can now pull in a reef or shake it out without having to go to mast base and pull slack through manually.

Hoisted mainsail with the 2nd reef already pulled in, when the sail hoist got to the second, then the first reef it just pulled the reef lines through the open clutches as we raised it to full height. (Would never do this before way to much strain on the winch and sail head, without manually feeding the lines)

Will advise if I come across any down side to this mod other than the cost of the line.

[Bean Counter]

Originally Posted by PaulinOz

Just swapped out 1st and 2nd reef line from 14mm Double braid nylon to 12mm Spectra braid. Currently 3 rd reef line used as Out-haul on mainsail.

Can now pull in a reef or shake it out without having to go to mast base and pull slack through manually.

Hoisted mainsail with the 2nd reef already pulled in, when the sail hoist got to the second, then the first reef it just pulled the reef lines through the open clutches as we raised it to full height. (Would never do this before way to much strain on the winch and sail head, without manually feeding the lines)

Will advise if I come across any down side to this mod other than the cost of the line.

Look forward to the report.

Are these pure spectra or covered?. If not covered how well do they hold in the clutch? We use the clutches for spinnaker bridle adjustment so hold the reefing on the horn cleats for reef 2 & 3. I guess a section of cover could be stitched on to spectra core at the clutch point as an alternative.?.

[PaulinOz]

"Are these pure spectra or covered?." Dyneema core and Polyester cover.

[sbaydreamer]

What types of blocks did you put in the sails?