Lazy jacks diameter

dlochner · Sep 23, 2020

¼" or 5/16" will be large enough if you go with plain Dacron lines. A little smaller if you go with something like dyneema. The lazy jacks don't take much of a load. On my 36' boat, I have 5/16" line. In this application the size is mostly about how easy it is to handle.

Hunter216 · Sep 23, 2020

fred1diver said:
Hey everyone, still working hard on the boat, today I replaced a halyard ( main)
And I removed the old lazy jacks, the rope is all crudded and no good anymore, it’s so rotted that I can’t even get a measurement to replace it. So what size ropes would be needed for a lazy jack on a 26footer ?

Take a read of this thread for some solid ideas.

Low cost, high performance lazy jacks

For years we have always saddle-bagged (large even flakes) the laminated mainsail on BlueJ's boom for storage. With 2 or more, this is an easy task due to the mast track and the full battens. No complaints, and it helps keep the main in great shape. But there are times when I think about lazy...

forums.sailboatowners.com

jssailem · Sep 24, 2020

Here are 2 articles about Lazyjacks. I suspect 1/4" would serve you purpose adequately. It is not like you have 47sq m of main sail weigh in at 65kg.

A Mainsail on a typical Catalina 30 would weigh in around 15kg. 1/4" diameter line can easily capture it on the boom.

DIY Lazy-jacks: Mainsail Tamers | Good Old Boat

goodoldboat.com

Lazyjacks for Your Mainsail

I have always liked lazyjacks in theory, but in practice I’ve found them to be a total pain in the backside. Even so mundane a task as hoisting a mainsail

www.sailmagazine.com

Michael Davis · Sep 24, 2020

We have 1/4 in. line on our First 38. Works fine.

dlochner · Sep 24, 2020

Go with ¼" it will be easier to handle and the cost difference will be negligible. Again, it is not about strength as it is about ease of handling. You could probably go with some 20 lb test monofilament fishing line, but that would hard on the hand!

Hunter216 · Sep 24, 2020

I don’t see the system as needing much strength unless you aren’t using a topping lift or boomkicker type device. If you forgot to attach the topping lift for example all the weight of the sail, boom and possibly a person leaning on the boom would be held up with the lazy jack system. Not good

From my experience the value is to have the lines in the right place so the sail doesn’t get hung up on any part. Ideally uncleat the halyard and the entire sail falls neatly on the boom, doesn’t block your view or catch much wind and stays put until you have time to tidy it up. The system should also be able to be pulled out of the way for hoisting the sail, can’t count the number of times I’ve had a batten catch under a lazy jack line before I figured out that you only need the lazy jack system to drop the sail

dlochner · Oct 1, 2020

fred1diver said:
I successfully made some eyes on bigger rope but the ¼" doesn't like me, so now I have 100' of rope and I can't do nothing with it

Tie knots.

dlochner · Oct 1, 2020

fred1diver said:
Dave do you mean instead of splices?

Fred, sorry for the curt response, I've been reading about our upcoming election.

Yes. For the short term a bowline will work.

Or you could try sewn splices.

Sewn Splices Two-Year Followup - Practical Sailor

Since 1974, Practical Sailor’s independent testing has taken the guesswork out of boat and gear buying.

www.practical-sailor.com

Jackdaw · Oct 1, 2020

On BlueJ (First 260) we use 4mm dyneema and some small low friction rings spliced on. The whole set up is very strong, almost invisible, and never in the way. We used to pull it forward for racing, but we've stopped doing that. I think the whole setup cost 30 bucks.

srimes · Oct 1, 2020

Jackdaw said:
On BlueJ (First 260) we use 4mm dyneema and some small low friction rings spliced on. The whole set up is very strong, almost invisible, and never in the way. We used to pull it forward for racing, but we've stopped doing that. I think the whole setup cost 30 bucks.

View attachment 185553

Looks like they're attached to the spreaders? Seems like that would help keep them out of the way. Any concerns with loading spreaders like that?

Captain Larry-DH · Oct 1, 2020

srimes said:
Any concerns with loading spreaders like that?

Nah. That’s the best way. mine are even further from the mast.

Jackdaw · Oct 1, 2020

srimes said:
Looks like they're attached to the spreaders? Seems like that would help keep them out of the way. Any concerns with loading spreaders like that?

they are, it does, and not really.

lots of new boats with jacks as standard equipment do this. As noted in the link above, using a strap and d-ring wrapped around from the top would make it even stronger. As it is, this is very strong.

kappykaplan · Oct 2, 2020

srimes · Oct 2, 2020

Jackdaw said:
they are, it does, and not really.

lots of new boats with jacks as standard equipment do this. As noted in the link above, using a strap and d-ring wrapped around from the top would make it even stronger. As it is, this is very strong.

I'll keep that in mind in case I decide to make some. I trailer my boat and have shied away from lazyjacks as they'd be one more thing to set up and take down, and my main is small enough that it isn't too hard to handle.