Lazy jacks - cord thickness/type?

[LittleSister]

I’m replacing the lazy jacks cordage. Those that came with the boat appeared rather thick to my eyes. They seemed to measure as 5mm to a firm material, but being old the surface was roughed up making them look more like 6mm.

I was thinking of going for 4mm, but is this likely to be adequate for my modestly rigged 27 footer (10 m mast, main variously listed as 13sq m & 14.7sq m).

Also, I assumed that braided nylon cordage would be the thing to get. Is that right?

 

[Poignard]

I used Liros Lazy Jack Line, 6mm dial and I have had no reason to be dissatisfied.

​

 

[lustyd]

Lazy jack line is a thing, I used that

Liros Lazy Jack Rope 6mm Silver | Force 4 Chandlery

Marlow PS12 Rope 4mm

 

[Daydream believer]

Marlow sell nylon sash cord in hanks. Forget the length per hank, but it is durable ( has to be for sash windows) & reasonably cheap. ( Or was when I used to buy it by the case) Couple of hanks will do you just fine.

 

[Tranona]

Lazy jack line is a thing, I used that

Liros Lazy Jack Rope 6mm Silver | Force 4 Chandlery

Marlow PS12 Rope 4mm

The Force 4 one is what came with my new stackpack from Kemps.

 

[MisterBaxter]

I think 4mm would be fine as long as the rigging arrangements mean that the lazyjacks don't ever end up carrying the weight of the boom and sail.

 

[lustyd]

The Force 4 one is what came with my new stackpack from Kemps.

Pretty sure it's the one I used too but can't be certain. the 6mm looks about right on my 36 footer. It splices like Dyneema and looks very neat.

 

[LittleSister]

Thanks, folks. I should have known there would be some yachting industry wheeze to get me to spend significantly more money than I’d originally intended!

In the process of searching for the proper silver encrusted lazy jack line some of you mentioned I came across something saying don’t use nylon as it stretches and becomes baggy and hence doesn’t hold the sail tidily when dropped. I thought that the general advantage of nylon rope was its ELASTIC stretch, and for these purposes surviving getting caught on the sail or having the weight of the boom accidentally put on it.

I am still in 2 minds about it, on grounds of cost and aesthetics. - if 6mm looks right on a 36 footer it will likely look out of place on my much smaller rig, not to mention causing even more windage to slow me down! (Plus I envisaged dainty little knots, not faffing about with numerous splices.)

 

[BabaYaga]

I used 5mm braided polyester line when I replaced them on my 17 sqm main sail last year. Still some elasticity.
No blocks or rings or splices, just bowlines. Last quite well.

 

[Tranona]

Thanks, folks. I should have known there would be some yachting industry wheeze to get me to spend significantly more money than I’d originally intended!

In the process of searching for the proper silver encrusted lazy jack line some of you mentioned I came across something saying don’t use nylon as it stretches and becomes baggy and hence doesn’t hold the sail tidily when dropped. I thought that the general advantage of nylon rope was its ELASTIC stretch, and for these purposes surviving getting caught on the sail or having the weight of the boom accidentally put on it.

I am still in 2 minds about it, on grounds of cost and aesthetics. - if 6mm looks right on a 36 footer it will likely look out of place on my much smaller rig, not to mention causing even more windage to slow me down! (Plus I envisaged dainty little knots, not faffing about with numerous splices.)

You should be able to make out how the 6mm looks on a modest sized boat. This is a 4 leg system using plastic thimbles.

 

[Boathook]

I’m replacing the lazy jacks cordage. Those that came with the boat appeared rather thick to my eyes. They seemed to measure as 5mm to a firm material, but being old the surface was roughed up making them look more like 6mm.

I was thinking of going for 4mm, but is this likely to be adequate for my modestly rigged 27 footer (10 m mast, main variously listed as 13sq m & 14.7sq m).

Also, I assumed that braided nylon cordage would be the thing to get. Is that right?

I used LIROS Lazy Jack 50 / 100 Metre Deal for my lazyjacks the other year. Sewed in my own thimbles, etc. Seem to be lasting ok so far.

 

[Daydream believer]

I whipped loops on mine then slipped clear heat shrink over the whipping & rope end so it made a smoooth finish. This then does not rub on the sail so much. As Tranona suggested , plastic rings worked well for me for 15 years. Although, when I renewed, I did change to stainless steel ones. The ends of the lines are connected to the cover with small shackles. The adjustment is done at the mast foot, at the other end, on the main lazy jack lines. No knots to come undone & a neat
installation.

I looked up Marlow for sash cord just now & could not see it. But compared to #11 this seems a better deal, at half the price, if you want some spare for flag halyards, tie down the mistress etc Nylon Sash Cord

There are cheaper suppliers out there- Amazon etc

 

[Stemar]

I have 4mm line, with SS rings rather than blocks, and it works fine.

On my old Snapdragon, I used some seriously cheap line from The Range, but it turned out to be polyprop, and only lasted a couple of years. I'd be leery of cheap nylon sash cord, as it may not have the UV resistance you need, but any polyester line should do. For Jazzcat, I got a clearance reel from You Boat because it was cheaper to buy the whole reel than the 30-odd metres I needed.

 

[Graham376]

I have 4mm line, with SS rings rather than blocks, and it works fine.

Same on my 38ft boat and they've worked fine for many years.

 

[MisterBaxter]

Bristol Rope and Twine are great if you want long lengths of cheap rope. They'll probably sell you a reel of 4mm polyester at a very good price.

 

[PetiteFleur]

I use 6mm braided polyester on my 33' boat as I have a lot of it, just renewed it this year as it had got grubby and chafed by the crosstrees. 5mm should be ok on your boat but don't use polypropylene as although it floats it does suffer from UV degradation.

 

[ithet]

Just renewing with 5mm 8 plat on 34ft. 4mm would be fine on 27ft.

I think pulleys are over kill on these size boats.

 

[alahol2]

I have 4mm line, with SS rings rather than blocks, and it works fine.

Ditto on 28ft. Braided polyester. Rings whipped onto line.