Foam luff and sail performance

[bdh198]

We are going to be replacing our non overlapping and furling head sail with a North Sails 3Di and they have suggested putting in a foam luff.

I've never sailed with a foam luff, but understand that it helps give a much better sail shape when sailing with a partly furled foresail. However, I also understand that this is at a cost of a slightly reduced performance when the sail is completely unfurled as the bulk of the foam interferes with the air flow over the luff.

I'm trying to decide whether the foam luff really is worth it in our situation. The foresail is non overlapping so the occasions we will need to be reefing it are limited (I can't actually remember the last time we sailed with a reefed foresail). If we did decide to go with it, are we likely to notice any significant loss in performance when the sail is completely unfurled? And is it likely to cause any other side effects we should be aware of, for example, interference with the luff telltales?

 

[KenMcCulloch]

We are going to be replacing our non overlapping and furling head sail with a North Sails 3Di and they have suggested putting in a foam luff.

I've never sailed with a foam luff, but understand that it helps give a much better sail shape when sailing with a partly furled foresail. However, I also understand that this is at a cost of a slightly reduced performance when the sail is completely unfurled as the bulk of the foam interferes with the air flow over the luff.

I'm trying to decide whether the foam luff really is worth it in our situation. The foresail is non overlapping so the occasions we will need to be reefing it are limited (I can't actually remember the last time we sailed with a reefed foresail). If we did decide to go with it, are we likely to notice any significant loss in performance when the sail is completely unfurled? And is it likely to cause any other side effects we should be aware of, for example, interference with the luff telltales?

All the foam luffs I have ever seen have been less than the thickness of the foil. Since that causes a good bit of turbulence itself I very much doubt if a foam luff has any detectable negative effect. Advantages far outweigh disadvantages imo.

 

[duncan99210]

All the foam luffs I have ever seen have been less than the thickness of the foil. Since that causes a good bit of turbulence itself I very much doubt if a foam luff has any detectable negative effect. Advantages far outweigh disadvantages imo.

+1 The foam infill on the luff is shaped such that it will be a good deal thinner than the foil. Indeed, it may even help to mitigate turbulence round the foil and onto the sail. Also helps to get a neat wrap when furling the sail completely so I can see no real downside to it.

 

[johnalison]

I think that my newish laminate 110% jib from OneSails has a rope instead of foam, on the grounds that it is less likely to lead to mildew, though the result is the same.

I can remember my first foam-luffed jib, actually a genoa, on my then Sadler 29. It replaced a conventional sail, both being simple cross-cut dacron. The tranformation was amazing; it meant that I could 'reef' the jib when the wind increased without incurring a major loss of pointing ability. I now regard it as indispensible and well worth the slight increase in cost.

 

[Tranona]

I have a 106% jib which rarely gets reefed down and was advised that a foam luff was really not needed and instead the luff was recut with a slight curve. On the odd occasion I have reefed it seemed fine. with previous boats with bigger genoas the foam worked well as reefing was more frequent and shape more critical. As others have said not sure foam made the full sail any less good, though.

 

[MoodySabre]

My 130% Crusader genoa has a padded luff - padded with rope. The shape when partly furled is much better. I can't see how it would affect performance because the foil is bigger anyway.

 

[Daydream believer]

If you are talking about a self tacking jib for a Hanse 370 then you should probably be able to carry the full ST in anything up to a F8 anyway. So how much sailing do you expect to do with it furled?
I would not bother if worried about it.

 

[BabaYaga]

We are going to be replacing our non overlapping and furling head sail with a North Sails 3Di and they have suggested putting in a foam luff.

I'm trying to decide whether the foam luff really is worth it in our situation. The foresail is non overlapping so the occasions we will need to be reefing it are limited (I can't actually remember the last time we sailed with a reefed foresail). If we did decide to go with it, are we likely to notice any significant loss in performance when the sail is completely unfurled? And is it likely to cause any other side effects we should be aware of, for example, interference with the luff telltales?

Bit surprising that you state foam on offer, as I believe North has used rope as standard padding for some time, certainly the case on my genoa, which is now six years old.
Regardless of material I don't think you will notice any loss of performance at all,. The choice will be the benefit on the few occasions reefed against the additional cost, IMO.

 

[bdh198]

If you are talking about a self tacking jib for a Hanse 370 then you should probably be able to carry the full ST in anything up to a F8 anyway. So how much sailing do you expect to do with it furled?
I would not bother if worried about it.

Thanks for all the helpful replies. It is indeed a headsail for a Hanse 370, and with a non overlapping jib we are able to use it fully unfurled in some pretty stiff breezes. However, if there is unlikely to be any significant loss of performance in having the foam padding (that is what North Sails are suggesting, but will question if rope is more suitable) then the additional cost becomes the deciding factor!

 

[DHV90]

Maybe worth having a padded luff on a big stretchy genoa, but with a good, non-overlapping laminate headsail you would be far better off flattening and tuning than reefing in my opinion. A lot of race boats will carry a blade jib until they start digging out tri-sails, so a 100% jib can be extremely flexible, no reason to suggest that flexibility can't be enjoyed on a cruising boat if that's what you have

If you dont reef the sail you've got, it cant be worth risking any sacrifices to potentially 100% of you sailing experience in the future for the chance that it might be some advantage in a situation you might never encounter.

my only experience with foam luffs is sailing on one boat a fair bit with a dacron headsail with a padded luff and it really did interfere, especially as the sail aged where materials shrunk/expanded differently and ended up with a quite out of shape luff area, and halyard tension suddenly became virtually useless, with the foam holding the luff in tension.

Did you specify anything like wind range to North?

 

[dunedin]

Personally I would definitely go for the foam luff.
We have this on a 106% North Cruising Laminate.

 

[Mr Cassandra]

I have inherited a set of 5 brown laminate racing sails, that have never been put on the boat from 1996. First 45
As I do not get anything but family sailing ,would i be able to use these sails on a furling system?
If I dont use them they will probally be stored in the shed for life.

 

[dunedin]

I have inherited a set of 5 brown laminate racing sails, that have never been put on the boat from 1996. First 45
As I do not get anything but family sailing ,would i be able to use these sails on a furling system?
If I dont use them they will probally be stored in the shed for life.

One factor could be luff length. We inherited laminate race sails with our previous boat but most were designed to be tacked off below the roller drum, so we’re loft insulation till we sold the boat.
One had been designed for the furler and worked for a short while. But no foam luff meant struggled to Windward when reefed, and no UV strip so soon died. Sailmaker decided cheaper to make new in Dacron than try to patch up laminate.

 

[johnalison]

My last two jibs have been laminate, though white rather than brown. My experience has been that they furl very well, without creases, and both have set well when part-furled with foam/rope luff.

 

[Habebty]

When I replaced my foam luff Genoa, the sailmaker (Doyle) convinced me to have a rope luff. The furled shape was less satisfactory so had another sailmaker(Jeckells) fit a foam luff. Foam every time for me.

 

[wotayottie]

We are going to be replacing our non overlapping and furling head sail with a North Sails 3Di and they have suggested putting in a foam luff.

I've never sailed with a foam luff, but understand that it helps give a much better sail shape when sailing with a partly furled foresail. However, I also understand that this is at a cost of a slightly reduced performance when the sail is completely unfurled as the bulk of the foam interferes with the air flow over the luff.

I'm trying to decide whether the foam luff really is worth it in our situation. The foresail is non overlapping so the occasions we will need to be reefing it are limited (I can't actually remember the last time we sailed with a reefed foresail). If we did decide to go with it, are we likely to notice any significant loss in performance when the sail is completely unfurled? And is it likely to cause any other side effects we should be aware of, for example, interference with the luff telltales?

You have a small foresail and rarely reef so its likely that the benefit will be small too. The boats that really gain are those like the Sadler 29 which was supplied with a small main and a huge overlapping genoa of 180 per cent. In your case its likely that the first couple of reefs are main only. And even when you reef the genoa you wont get than many rolls on the spar

 

[scottie]

Are you fitting track on the coach roof we did and the difference is marked also on a370

 

[bdh198]

Are you fitting track on the coach roof we did and the difference is marked also on a370

That's interesting. Have you got any photos to show how this was done?