Fully battened or conventional battened mainsail

[Dietrying]

I need a new mainsail (35' Beneteau) and am wondering about a fully battened or a conventional main. Historically, opinion seems to be split (here and elsewhere) but I'd appreciate opinions. So far the summary of what I've learned seems to be

Main potential issues seem to be

• Weight aloft
• Chafe when going downwind
• Inability to depower / scandalise the rig
• Possible friction issues
• Less 'tweakable'
• need to point upwind to drop sail

contrasted with pluses including

• will draw well, even in low wind conditions
• improved performance (better sail shape, points higher and faster)
• reduction in heeling (due to above)
• easier to stow if using stackpack
• less requirement to 'tweak'...

I'm currently minded to go with a FB, but it is quite a lot more money and I'd like to canvas as much opinion as possible

 

[SimonJ]

Can I suggest you compromise - have top 2 battens full length and bottom 2 made mid length.
This overcomes most problems with all full length but gives most advantages.
However you will need good batten cars (as for all full) at the top and these do not come cheap. For the last 40000 miles this arrangement has served me well.
I rarely see this recommended but believe me as a onetime sailmaker it works very well!

 

[Bobc]

I have a fully battened main now, and I doubt I'd go back to a soft main again.

If you're going to do it, fit a stackpack and lazyjacks, and make sure you have good cars on the mast track.

Definitely worth the extra money IMHO.

 

[GrahamM376]

I have a fully battened main now, and I doubt I'd go back to a soft main again.

If you're going to do it, fit a stackpack and lazyjacks, and make sure you have good cars on the mast track.

Definitely worth the extra money IMHO.

+1

I've had 2 boats with conventional battens and 2 with full length ones - full are by far the best IMHO.

 

[AngusMcDoon]

I find that with mine head to wind the battens go S shaped and it sits there quietly with no flapping completely depowered. In light winds it needs a good heave on the boom to get the battens to pop out of their S shape and back to a sail shape.

 

[Javelin]

With my racing hat on I'd argue the toss about three of your plusses,

- will draw well, even in low wind conditions
- improved performance (better sail shape, points higher and faster)
- reduction in heeling (due to above)

I'll buy the argument it if we're talking about a boat that regularly sails faster than hull speed like a cat, tri or uld but for a displacement boat sailing at best at displacement speed I can't see it.
For performance I'd stick with a soft sail.

For ease of use, plug and play nature of the sail then I accept the argument.

 

[Twister_Ken]

With my racing hat on I'd argue the toss...
...For performance I'd stick with a soft sail.

You'd be outnumbered in a racing fleet, I suspect

 

[Hermit]

Can I suggest you compromise - have top 2 battens full length and bottom 2 made mid length.
This overcomes most problems with all full length but gives most advantages.
However you will need good batten cars (as for all full) at the top and these do not come cheap. For the last 40000 miles this arrangement has served me well.
I rarely see this recommended but believe me as a onetime sailmaker it works very well!

I have this system as well and it works superbly.

 

[Twister_Ken]

Can I suggest you compromise - have top 2 battens full length and bottom 2 made mid length.
This overcomes most problems with all full length but gives most advantages.
However you will need good batten cars (as for all full) at the top and these do not come cheap. For the last 40000 miles this arrangement has served me well.
I rarely see this recommended but believe me as a onetime sailmaker it works very well!

That's the route I went - 3 full length at top, 2 three-quarter length lower down.
Happy with my choice. The 'soft' bottom allows a degree of depowering.

 

[reeac]

I find that with mine head to wind the battens go S shaped and it sits there quietly with no flapping completely depowered. In light winds it needs a good heave on the boom to get the battens to pop out of their S shape and back to a sail shape.

That sounds as if the battens are in too much compression. I set mine so that there is only a smidgeon of compression.

 

[doug748]

I have both.

I generally use the FB main but have the odd season with the old sail. On a smaller boat (with a very small "masthead" main) I feel there is little in it. The biggest plus for me, singlehanding, is that the fully battened sail will rarely flog.

I guess the acid test is that I have just bought a new main - Fully battened.

 

[Deleted member 36384]

I should think that your decision should be based on what you intend to do with the yacht. There is no doubt in my mind that an FB mainsail will be more efficient than a standard mainsail and will therefore allow the boat to be sailed faster. There is also no doubt that a poorly set up FB mainsail is a drag - in so many ways. If you intend to race regularly then go for the FB mainsail.

On my own boat I changed back to the standard mainsail from an FB one. My tub is firmly in the cruising mould and the FB mainsail had low tech batten cars which made hoisting and lowering a pain. I also found that the confined waters and slow sailing speed control was not that great with the FB mainsail. So I decided to get rid of it. The standard mainsail makes it far easier to control boat speed and much less hassle which suits my cruising needs; I use sail for the majority of the time when carrying out manoeuvres out with marinas and harbours. I also removed the stack pack and lazy jacks for aesthetic reasons - I simply do not like a stack pack on the boom all the time (purely a personal taste as I do appreciate the convenience of it).

If cruising is what you intend to do all the time I would recommend that you do not need the FB mainsail and would council saving the extra money for something else.

 

[AngusMcDoon]

That sounds as if the battens are in too much compression. I set mine so that there is only a smidgeon of compression.

Boat is a trimaran. I have no backstay which allows a large roach. Large roach requires high batten compression. If the batten compression is set to as you describe then I get a ridge behind my mast when the mainsheet is pulled in. Maybe my original comment is not applicable to the OP's situation. I have never sailed with a back-stayed rig and a fully battened sail.

 

[Dietrying]

Thank you for your input. However, I'm still torn between the two. Here's a bit more about my sailing profile

I mainly cruise at weekends on the East coast, but with one or two long trips to Europe/CI.

I don't race - at least not at the moment. However, I like to have the boat sailing as fast as I can. I also appreciate being able to point (well, travel) to windward as efficiently as possible and I appreciate being able to get the best from a sail setup. The engine gets used for most manoeuvrings but I do practice MOB under sail. Ease of handling is important as I'm not one to avoid opportunities to make life easier.

My main concerns (I think) are the issue of chafe - my boat has swept spreaders, and de-power.

My primary aspiration for the new sail is not so much to increase hull speed, but definitely to improve windward progress.

The current main is a roller furling job (the furling gear is, of course, being removed...)

 

[Twister_Ken]

Any new mainsail will be more efficient to windward that your old roller furler.

Any main is at risk of chafe, downwind with swept back spreaders. You can mitigate this by specifying sacrificial spreader patches on the sail.

A part full/part long batten sail allows a good degree of depowering upwind, depending on your use of the sail shape and sheet controls. Downwind is a different matter, but the same is true of a soft sail. Certainly I can put a big bubble in the luff of my main by easing the sheet and/or traveller to avoid being over-powered in gusts.

 

[Deleted member 36384]

Chafe can be managed by sacrificial strips on the sail. De powering can be managed by altering the angle of approach more upwind to the objective when under sail. If optimum pointing is very important to you, get the FB mainsail.

 

[flaming]

I should think that your decision should be based on what you intend to do with the yacht. There is no doubt in my mind that an FB mainsail will be more efficient than a standard mainsail and will therefore allow the boat to be sailed faster. There is also no doubt that a poorly set up FB mainsail is a drag - in so many ways. If you intend to race regularly then go for the FB mainsail.

Racers don't have FB mainsails.... FB is brilliant for cruising, gives loads of power in low winds, nice stable shape, and tames itself nicely when dropping in strong winds.
They aren't suitable for racing though, as depowering is quite limited, reefing is pretty much the only option and the shape is way less tweakable.

This does change once you get to "square top" sails that require separate backstays. But for normal cruiser racer types I would get FB to cruise, and "standard" to race.

 

[Deleted member 36384]

Racers don't have FB mainsails.... FB is brilliant for cruising, gives loads of power in low winds, nice stable shape, and tames itself nicely when dropping in strong winds.
They aren't suitable for racing though, as depowering is quite limited, reefing is pretty much the only option and the shape is way less tweakable.

This does change once you get to "square top" sails that require separate backstays. But for normal cruiser racer types I would get FB to cruise, and "standard" to race.

Well, there you go, I would never have thought of it that way for low wind speed performance, which is mostly the summer cruising winds. Taming is not an issue for a standard main sail when dropping it strong winds either so a moot point in my opinion.

For my understanding why doesn't a FB sail de-power if you ease the sheets in a gust? Would it not just choke off the slot or even bow the battens to windward, or it does but this is too inefficient compared to backwinding a standard batten sail?

 

[sideshowbob]

'Can I suggest you compromise - have top 2 battens full length and bottom 2 made mid length.
This overcomes most problems with all full length but gives most advantages.
However you will need good batten cars (as for all full) at the top and these do not come cheap. For the last 40000 miles this arrangement has served me well.
I rarely see this recommended but believe me as a onetime sailmaker it works very well!

+1 we always carry spare top batten cars!

 

[Houleaux]

Lots of useful info here: http://www.kempsails.com/yacht-sails.html

No connection other than a satisfied customer.

I have a Kemp Power Main. It was on the boat when I bought her so I can't offer any comparisons from direct experience, but it might be of interest to you given your dilemma. I'm happy with it!