For some reason, the list server seems to have stripped out the pasted excerpt from the archives.  Let’s try that again.

Roger Pihlaja
S/V Dynamic Equilibrium



Hi Rodney,

Attached below is a thread from the archives, 1st published ~20 years ago.  There is lots more discussion on genoas and roller furlers in the archives and I suggest you look at this resource.  There was also a lengthy discussion thread on this subject last winter on the list, although I don’t know how to search for it.

Roger Pihlaja
S/V Dynamic Equilibrium

____________________________________________________________________________________________________

OK, what's a foam luff pad & why do you want one?

There is a difference between the optimum airfoil shape for light air & heavy air. Light air sail shape needs to have a more extreme curvature than a heavy air sail shape. Sailmakers call this more extreme curvature "deeper draft". The ideal roller furling genoa would have a deep draft shape when it is fully rolled out & a progressively shallower draft shape as the sail is rolled up for use in stronger winds. The foam luff pad on a roller furling sail is currently the best technology to achieve this progressive reduction of draft as the sail is rolled up.

Seen from the side, the foam luff pad looks like half of a long skinny ellipse sewn into the leading edge of the sail (i.e. the luff). It can be literally made of a single layer of closed cell foam sewn into the sail or it can be also be made from several layers of heavy sail cloth. All it really needs to have is extra thickness in the middle section of the luff. To work properly, the roller furler must have independent upper & lower swivels & the middle part of the luff must be firmly attached to the furling tube. OK, when this sail is completely rolled out, it has the proper deep draft shape for light air. As the sail is rolled up, the middle part of the luff is attached to the furling tube & is thus forced to roll up with the furling tube while the upper & lower ends of the sail are attached to independent swivels & do not roll up as fast. The foam luff pad sewn into the middle portion of the luff gets rolled up 1st. Its extra thickness adds to the effective diameter of the furled sail as furling proceeds. Since the middle portion of the luff has a bigger diameter than the ends, the middle part of the sail gets rolled in faster than the ends - i.e. the deep draft portion of the sail cloth is rolled up proportionately faster than the rest of the sail. The sail shape becomes progressively shallower draft as we roll up the sail, exactly what we want to happen for sailing in stronger winds. Pretty cool eh? When you combine this technology, with the inherent strength & lighter weight of the latest generation of composite sailcloth & the latest radial designs, you get an integrated roller furling foresail system that is simply light years ahead of the OEM factory roller furling foresail. The composite sailcloth & bi-radial construction enables the sailmaker to computer design the desired sail shape into the sail - not only when completely deployed in light air, but also as the sail is furled up & wind loaded.

A word of warning, the high tech sailcloth & roller furler is more expensive to purchase & the composite sailcloth does not last as long as straight Dacron. It is also not as idiot proof to sail with as the standard system. Allow me to explain:

With the standard roller furler & foresail, poor furled sail shape & sailcloth distortion under heavy wind load combine to function as a sort of "safety valve" against helmsman & sail trimmer errors. The top half of the sail distorts under the load of a wind gust & permits most of the wind's kinetic energy to spill off without causing much heeling &/or thrust. This results in the standard rig being pretty much immune to a knockdown no matter how badly the crew screws up. Upgrade the genoa to the system described above & it's a whole different ball game. The sail's construction & the super strong composite sailcloth have the designed sail shape locked in & it won't significantly distort right up to the point of sail cloth failure. In the hands of an expert crew, this means the kinetic energy in a gust of wind is instantly converted into thrust that causes the boat to surge ahead. The boat seems to "squat" in the water as the bow starts to climb up it's own bow wave. It can set you right down into your seat. Its great fun & a rather additive experience! However, if the crew screws up, the sail will not "save" you by distorting & spilling wind. If the helmsman doesn't bear off &/or the sail trimmers let the sheets fly at the proper moment in a heavy gust, then the boat will be knocked onto its side faster than you can say, "Holy shit!" If you are not willing to pay strict attention in heavy air, then do not install this system on your boat. However, don't be surprised when you see more & more of these sails & roller furlers out on the water. You'll usually be observing them from behind, get used to it! This is mature, well proven technology that really really works.

Roger Pihlaja
S/V Dynamic Equilibrium
19 Apr 2002


Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows

From: John Keyser<mailto:retro53 at msn.com>
Sent: Friday, May 27, 2022 2:41 PM
To: The Rhodes 22 Email List<mailto:rhodes22-list at rhodes22.org>
Subject: Re: [Rhodes22-list] Source for a 130 Genoa

Hi Rodney,

   I bought an older (1980) Rhodes 22 with a roller furling Genoa (maybe 140) carrying a North Sails logo on it about 4 years ago.  I keep the boat in the Delaware River, and because it's always advisable to stay within the river banks, there is always a lot of tacking involved when we take her out for a sail. For the first two years, I was not terribly happy with the boat's ability to tack. Half of the time, she would end up in irons with the headsail often not making it around to the other side of the boat, in all kinds of wind conditions. Now I know there are many reasons for this to happen, and I'm sure that it was me (although I never had the problem with any of my other boats).  Luckily, as it turned out, at the end of the second year, the Genoa developed a tear, and upon further examination I decided to get a new sail rather than try to have it repaired.

  My sail search took me to Precision Sails Ltd, in Sidney, BC, Canada. A team of designers worked with me to understand my sailing needs and design the most appropriate sail. We settled on a 115 headsail made from their 400 series Advanced Dacron 6 material. It cost $745 including delivery.  When I put it in service last year, the boat was transformed. Tacks are now effortless and it is now very unusual to have any difficulties maneuvering under sail. In addition, she feels a lot more balanced under full sail, with just a nice touch of weather helm - previously there was some lee helm unless the Genoa was partly furled.  I am a very satisfied customer.

 Best Regards,
John Keyser
Deci-Belle

________________________________
From: Rhodes22-list <rhodes22-list-bounces at rhodes22.org> on behalf of RODNEY BROWN <rnelson204 at gmail.com>
Sent: Wednesday, May 25, 2022 6:26 PM
To: The Rhodes 22 Email List <rhodes22-list at rhodes22.org>
Subject: [Rhodes22-list] Source for a 130 Genoa

Hello gang, I’m going to spring for a 130 Genoa. Any suggestions on sailmakers? material? What are the advantages of adding a luff pad?


Thanks in advance for your suggestions and insights.

Rodney