In mast furling sail vs semi batten

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cmedsailor

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Hello,
Could you please tell me advantages and disadvantages of an in-mast furling main sail vs a conventional semi-battened main sail (please do not compare with a full batten main sail)?
Thanks
 
I have full battens and I think they're the way forwards /forums/images/graemlins/wink.gif

Seriously though, in mast furling sails do not set as well, and thus give you the performance of a normal sail.

The other thing to consider with in-mast furling is that although when new it's time saving and simple, it is not a fail safe in many instances... if it all goes horribly wrong you cant just drop the sail, as it'll be tangles inside the mast.

I use full battens and they're brilliant, coupled with batten cars the sail goes up and down with ease! It never flogs and holds its shape in light winds.

Good luck with your search for a new sail, I hope you come to a decision soon!

Ben
 
In mast.... totally variable reefing options, very easy reefing, on most points of sail rather than having to head into the wind....

Performance.... yes its not quite as good as a fully roached slab reefed main.... but we can happily sail at 8kts in a breeze, and have hit 11.5kts, and more surfing.... how much more would you want?

no pesky bag to zip up and therefore trips to the coachroof, no pesky reefing lines cluttering the cockpit....

pros and cons both ways, but you'll hear the traditionalists crying that in-mast is the spawn of satan.... same as many did for roller foresails.... and now everyone has them...

Overall.... in mast main... designed for cruisers....not good for racing, or high performance sailing, but great for relaxed and easy cruising....
 
What would "loss in performance" mean for a 36ft sailing boat with furling main sail vs semi batten?
And in what conditions is this more likely to happen? Light winds, strong winds?
Sorry for all those questions buy I need to get a good picture of things before deciding what I would like to buy.
Thanks for the help.
 
I've used both

Disadvantages.
When using reduced sail the weight of the sail is still up the mast, conventional reefing lowers this weight which gives less heeling effort.

Slower to reef than roller cars and a single line system. With roller cars on the main we had an instant drop when letting the halyard go.

Risk of failure/jamming, and having difficulty dropping remaining sail.

Advantages
visibility as boom doesn't have a huge stack pack which obstructs helms view.

No ropes/reefing lines dangling in the cockpit after reefing

Less effort to unfurl as you're not lifting the sail up the mast.
 
Less power without battens, so in a steep choppy sea you'd have to bear off to keep your way on (probably)

Just thought of another disadvantage
When reefed, you don't get as flat a sail as with slab reefing, which when its really windy you need. Any fullness (which will get worse as the sail ages) makes the boat more difficult to handle in extreme conditions.


Hope that helps.
 
Efficiency - the in-mast main usually requires the leech to be cut a little hollow in order to prevent it continuously fluttering (and thus suffering wear), and this results in a rather less efficient shape.

The (fully) battened sail can even be cut with a substantial roach, resulting in a very powerful sail (in practice probably only for racing boats though, I don't know how many cruising mains are really cut this way, as the leech could end up interfering with the topping lift or even the backstay- but at least they aren't deliberately cut hollow...)
 
Here I go, singing the praises of a vertically battened in mast furling main. The MaxiRoach we had on our Sadler 29 was excellent. It never jammed and provided a good sail shape when reefed down. For a single-hander it would be a boon because reefing is so easy. Key disadvantage for us was the fact that it was a retrofit on a boat not designed for in-mast furling, which added more weight upstairs. True, if it does all go pear-shaped, you have a major problem, but provided the mechanics are kept in good trim it should be fine. Performance wise, we found it pretty good. That said, we have a fully battened "normal" main with roller cars on our current boat and reefing is pretty quick and easy, although you do have to go out of the cockpit to pull down the reef cringle to the rams horn.
 
Advantages;
Much easier for short handed cruising, since one person can reef/unreef/set/furl the mast rolled main.

Disadvantages:
1. Mast weight increase reduces boat stiffness a little.
2. Shape less efficient - lose 1 or 2 deg pointing - if you're a good enough helm!
3. When sail gets old and baggy, it starts to jam when unrolling.
4. Installation more critical - to keep tensions correct and mast straight.
 
What is wrong with the V boom reefing systems.

At least you can not get it jammed up there.

As for the difference: light air sailing the wind speed is variable with height from the water. So the place were you need the area most is missing.

Mains have a problem with having a big mast at the front of the aerofoil. If the canvas area is small in proportional to the mast width then they are much less efficient. So the top of the sail without battens is doing very little for you other than holding up the middle of the sail.
 
With in mast furling you lose quite a lot of area compared to a conventional main. Your light winds performance will really suffer as a result.
As others have mentioned the set up is key, the mast needs to be set up perfectly straight and as vertical as possible to avoid jams.
The mast section is also often thicker and heavier, meaning that the overall weight aloft is subsantially higher, making the boat more tender and also likely to pitch more in a seaway.
 
What is your opposition to full batten slab reefing out of interest?

Surely for the cost of setting up in mast furling, you could run to a fully battened main?
 
I'm with both Morgana and jimbaerselman

I would add though, as an ex-racing skipper, unless you are VERY keen on perfect sail trim, you will not notice the performance difference or indeed the suggested increased tenderness of the boat, particularly as in-mast furling rigs are generally less tall (and therefore have less aluminium in the air to start with.

Ease of use makes it preferrable for handling in my book, particularly in the Med where the wind can get up from nowhere in minutes and reefing needs to be quick and easy.

Also allows me to sail whilst madam sun-bathes as apparently handling halyards keeps her skin white!!!!!!!!

I hear a lot of people referring to jams when furling, but have never personally met anyone who has experienced it.

Yer pays yer money.......
I know what I would order the next time round though, if for a cruising yacht..
 
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I would add though, as an ex-racing skipper, unless you are VERY keen on perfect sail trim, you will not notice the performance difference

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Well, as a current racing skipper, I have to disagree with you. I've sailed with in mast furling a number of times and I have never been at all satisfied by the shape or power of the sail, and was consistently a knot or so down on an identical boat with a regular main.

In mast is a valid choice for a cruising boat, but choose it with your eyes open, you will lose performance.
 
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I hear a lot of people referring to jams when furling, but have never personally met anyone who has experienced it.



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Well you have, virtually, now. I have two friends, one with a Swedish yacht, the other with an Abel (a US design) that have both had their furling gear jam. One when a headboard ripped and he was stuck with the sail out, the other when he was trying to reef and the sail jammed up in the reefing tunnel.

Given that lines can be led back to the cockpit for both slab and in-mast, it seems to me that in-mast doesn't have many advantages other than the ability to reef to suit the exact wind rather than the step change of slab reefing.

Given the potential jamming probs, it will be battened slab for me.
 
the cost difference

Aside from the performance issues I would have thought that retro fitting a furling main would be prohibitively expensive compared to buying a new semi or fully battened main.

If buying a new boat then maybe there is not so much of a price difference.
Overall I would have thought that buying a roller main (and associated rigging) would more expensive than semi or fully battened sail. Maybe someone else that has looked into this in detail could confirm?

FWIW I have sailed with all 3 and prefer fully battened for sail shape, performance, longevity and ease of use (relative to soft).
 
Re: the cost difference

The reason I am comparing semi batten with furling is because I am planning to buy a boat and top favourites in my list are a Beneteau Oceanis 361 (perfect size, perfect room for family cruiser but with in mast furling main sail) and a Jeanneau Sun Odyssey 34.2 with semi batten main sail. Even if and when I buy a new sail for the Jeanneau it will most probably be again a semi batten since I am not interested in racing.
 
Re: the cost difference

One thing to clarify...

Fully battened sails are not used very often on racing boats. There are mainly a cruising sailors item as they resist flogging, don't punish bad trim as much and are easier to handle.
 
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pros and cons both ways, but you'll hear the traditionalists crying that in-mast is the spawn of satan.... same as many did for roller foresails.... and now everyone has them...


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I seem to remember the time (not so long ago) when you were a traditionalist /forums/images/graemlins/shocked.gif /forums/images/graemlins/blush.gif

I might stil have the e-mail: no in-mast furling, no lateral galley, etc...
Now look at you. /forums/images/graemlins/shocked.gif

Traitor /forums/images/graemlins/grin.gif /forums/images/graemlins/wink.gif /forums/images/graemlins/tongue.gif
 
Just ask the dealer when placing your order to get you a full battened sail rather than part and your problems will be over...

Get a quote though, and another quote to have no sails with the boat and get a quote from a sail makers as that may work out more economical...

Fully battened sails are great for so many reasons...
 
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