Caring for my carbon fiber sails

[longjonsilver]

My new to me, Cross 24 trimaran, has almost new carbon fiber main and jib. The main is square topped and fully battened. i was sailing downwind yesterday and noticed that the main battens were severely bent due to the upper shrouds that also support the mast aft. Shud i be worried about this?

i have read this about carbon fiber:

https://www.northsails.com/blogs/nor...ight-materials

What else do i need to know about my sails?

jon

[thinwater]

You don't ease the main that far on boats with aft-swept rigging, and particularly not multihulls. Sail more on a reach, and even when downwind, don't fully ease the boom.


Obviously, this is not good for the battens or sail. If you are going to abuse the sails by resting them on the rigging, you don't need carbon sails.


"... Carbon fibers are impervious to UV damage and have extremely high modulus (low stretch), but are quite sensitive to flex. If you take a raw carbon fiber tow (yarn) and fold it in your fingers it will snap after only one or two hard folds...."

[sailingharry]

I don't sail a multihull, and I don't have carbon sails, so I know butkiss about your problem. But you should listen to Thin. He is an engineer and an experienced multi sailor. His thoughts are gospel.

[Tupaia]

Look at them enjoy them and accept that they won't last long on a cruising boat. Unfortunately, failure tends to catastrophic so keep an eye out for flex cracks or tears and keep a roll of gaffer tape on board.

[longjonsilver]

Originally Posted by thinwater

You don't ease the main that far on boats with aft-swept rigging, and particularly not multihulls. Sail more on a reach, and even when downwind, don't fully ease the boom.


Obviously, this is not good for the battens or sail. If you are going to abuse the sails by resting them on the rigging, you don't need carbon sails.

So you're telling me to tack downwind from broadreach to broadreach?

[sailingharry]

Originally Posted by longjonsilver

So you're telling me to tack downwind from broadreach to broadreach?

That's what he's saying. Fast multis are MUCH faster doing that. Google around, you can find the Polar Diagrams for your boat. They usually will include the fastest downwind angle. Also, most wind instruments, including the very common Raymarine st60 series, will display VMG (velocity made good) which tells you how fast you are going downwind. Adjust your course for the highest VMG.

[ggray]

If your traveller is not long enough so that you need to ease the mainsheet, rig a preventer to help hold the boom down. That will help keep the sail off the shroud.

[fxykty]

Originally Posted by longjonsilver

So you're telling me to tack downwind from broadreach to broadreach?

That’s generally fastest and you probably have a code sail for exactly that purpose.

But if you’re just cruising and happy to poke along, go any angle you want. Just don’t, as Thin writes, ease the main so far that the sail and battens touch the rig. If you want to go DDW then consider lowering the main completely.

[thinwater]

Originally Posted by longjonsilver

So you're telling me to tack downwind from broadreach to broadreach?

Yes. And for those times when dead down wind seems faster (it will be in rivers and some wind conditions), you still keep the main in little. Don't let it bend over the shrouds. This does make accidental jibes a little more problematic, but a trimaran can barberhaul the jib WAY out, so you can actually keep the wind just a little on the windward side.

[longjonsilver]

Thanks Thinwater, and others. Tacked downwind today and its totally doable! Question tho, when flaking the sails on the booms (jib has a club) the sail naturally wants to lay flat making a hard crease. What to do?

[fxykty]

Originally Posted by longjonsilver

Thanks Thinwater, and others. Tacked downwind today and its totally doable! Question tho, when flaking the sails on the booms (jib has a club) the sail naturally wants to lay flat making a hard crease. What to do?

Don’t press on the crease. The sail will soften over time and folds in the same position is fine as long as the folds aren’t pressed tight.

[longjonsilver]

More on sailing my Cross 24 Trimaran. It seems like no matter which direction i go i am setting the sails for a beat or a beam reach, cuz the wind seems to be from ahead. Even on a deep broad reach the wind feels like i am on a beam reach.
Thots on my sail trim?

[fxykty]

Originally Posted by longjonsilver

More on sailing my Cross 24 Trimaran. It seems like no matter which direction i go i am setting the sails for a beat or a beam reach, cuz the wind seems to be from ahead. Even on a deep broad reach the wind feels like i am on a beam reach.

Thots on my sail trim?

You have a relatively fast boat that drags the apparent wind forward due to its speed. Extreme examples of this phenomenon are ice boats, Sail GP and America’s Cup foiling monohulls - they are trimmed for upwind no matter which direction they’re going.

Trim to the apparent wind angle and you’ll be fine. Are you having any problems with your trim?

[fourlyons]

Originally Posted by longjonsilver

More on sailing my Cross 24 Trimaran. It seems like no matter which direction i go i am setting the sails for a beat or a beam reach, cuz the wind seems to be from ahead. Even on a deep broad reach the wind feels like i am on a beam reach.

Thots on my sail trim?

As fxykty said, you have a fast boat. Even on my fairly heavy mono, if I put the asymmetrical spinnaker up in the right conditions, I can pull the wind forward to 40 degs apparent. Remember, you are always sailing (trimming to) the apparent wind, not true wind.

[longjonsilver]

Originally Posted by fxykty

Trim to the apparent wind angle and you’ll be fine.

Thats what i have been doing.

Are you having any problems with your trim?

.

The fully battened main and partially battened jib are easily trimmed - at least to my eye. Even today in 6-8 knots i had reasonable trim even tho as a singlehander i had trouble tensioning the main halyard (perhaps i need a small winch) and two of the battens up high came out of their pockets, because i took the main off the mast and boom to put it in the forward cabin for the hurricane. The lock for the batten musta popped off sometime in the operation.

edit: if i had a good pic of Mija i wud change my avatar.