Finding a root cause of torn sail

[Mrkva]

I was sailing close hauled, Najad 320 (so 32 footer) in 15-20kts wind, mild seas. Full main, jib furled to about 100%.


I wanted to try to squeeze a bit more VMG from the boat and put a bit more tension on the mainsheet. After that I noticed I haven't left enough slack in topping lift, so a crewmember went to mast to loosen it a bit more (and when doing so, he probably loosened the outhaul brake).



The moment the boom dropped a bit mainsail moved about 30cm to the main, where it created a fold.


I asked the crew to pull the outhaul using a really small winch with integrated handle. At that point a *pop* sound was heard and 40cm long horizontal tear appeared in the cloth near the leech just below the 1st reefing eye.



Can you give me a suggestions what have been wrong? I feel this wouldn't have happened had the mainsheet been loose before retightening the outhaul. But at the same time, I still don't understand the exact mechanism of the damage...
Can someone chime in?

[wholybee]

Originally Posted by Mrkva

I was sailing close hauled, Najad 320 (so 32 footer) in 15-20kts wind, mild seas. Full main, jib furled to about 100%.


I wanted to try to squeeze a bit more VMG from the boat and put a bit more tension on the mainsheet. After that I noticed I haven't left enough slack in topping lift, so a crewmember went to mast to loosen it a bit more (and when doing so, he probably loosened the outhaul brake).



The moment the boom dropped a bit mainsail moved about 30cm to the main, where it created a fold.


I asked the crew to pull the outhaul using a really small winch with integrated handle. At that point a *pop* sound was heard and 40cm long horizontal tear appeared in the cloth near the leech just below the 1st reefing eye.



Can you give me a suggestions what have been wrong? I feel this wouldn't have happened had the mainsheet been loose before retightening the outhaul. But at the same time, I still don't understand the exact mechanism of the damage...
Can someone chime in?

How old is the sail? My first guess is that it is worn out/damaged by the sun. Especially being on the leach, if it is not under a *new* sail cover when stowed. I say new, because after 5-7 years Sunbrella loses its UV blocking properties, even if it structurally seems ok.

Take a bit of sail, and fold it. Try to tear it with your hand, from the fold perpendicular to it. On a new sail you should not be able to. On an old sail, quite easily, and a sail that is used but still has some life left, somewhere in the middle.

[Jammer]

What Warren said. Chances are that the sail was already shot. When you take it to a sailmaker to get it fixed they'll tell you for sure.

[Mrkva]

The sail is between 35 and 3 years old. There's barely any mold or mildew stains and it looks like it still has a proper shape, at least when not under load). On the other hand, it has a boat model number and hull number on it, and I think there is a name of the 1st owner on the sailbag, so I guess it might be original.
The boat is in the baltic sea, so there's not that much sunshine over the summer and the sail is usually stowed indoors over the winter...


I had them with a sailmaker 2 years ago to install patches over scratches from spreaders and he wasn't suggesting I should get a new one.


What I'm trying to do is to exclude any user error - I would very much like to avoid ruining a new sail by something I **** up.

[wholybee]

I don't think anything with the outhaul would tear a sail up by a reefing cringle. But if the sail was old, the normal load of the mainsheet pulling on the leech might. It could be that the topping lift was taking the load normally on the sail, and it was the releasing of the topping lift that did it. I would not consider that user error, but just an old sail that failed.

[MikeHoncho]

the sun

[Nautes]

Entroy which is directly correlated with time and usage.

[Jim Cate]

FWIW: It is near impossible to tear a dacron main that is not degraded by UV damage. Seams can let go, but ripping the cloth away from seams is quite unlikely, user error or no. I think that you can absolve yourself of error!

Another test for the cloth, as advised by Bacon sails for their customers, is to take a reasonably sharp pencil and try to poke it through the cloth. If you can do so, it is kaput and not worth repair. If it resists, it is possible that it is OK.

Good luck with the new sail, and don't worry about ripping it!

Jim

[Joli]

Sails wear out but are remarkably durable for many miles and many years. Our 4 year old main has about 22,000 miles on it now and is still structurally fine but needs to be recut to remove and reposition the draft. The sun is very hard on sail cloth, keep it covered when not in use.

[Mrkva]

I hate to leave threads I've started "unsolved", so there's a couple of latest findings.
There's pulley system with at least 1:2 (possibly 1:4) purchase in the boom. Together with the small winch it probably overstretched the sail. That being said, a new mainsail is awesome... There's a significant improvement in how the boat behaves.



Anyways, this season I got a ~30cm tear in a genoa in sudden storm - but that sail was shot, I can easily tear apart the outermost (when furled) ~20-30cm by hand with ease.

Oh, the joys of owning a boat!