battens tapering

What is your opinion regarding battens tapering? In my fleet there are opinions against tapering sustaining that the sail is originally too hollow and tapering worsen its shape.



If you are pro batten tapering how much is enough?

How many battens do you advise to taper?

Do you still reccomend it if the battens are used with an old and supple sail?

I tapered a set of battens, and I believe that I ruined a set of battens. I bought another used set...not tapered...and believe that my boat performs better.



The only time that I think the tapered battens helped was in extremely high winds. All other conditions, I felt like they hurt my performance.



David

my 81 has the original sail i think. its not great but its ok. i could look up at the sail from underneath and see the sail had a semicircular chord. i sanded the front half of all the battens, gradually tapered until the 'round' part of the stock batten is sanded off to the 'flat' part about a foot from the end. now my sail has a nice airfoil shape, and i think its faster. i also seem to be pointing higher.

I have read about batten tapering and spoken with others about this. In order to stiffen the sail by tapering battens, one must buy two or three new ones first ( bottom battens), then move all of the existing battens in the sail up two or three pockets and fill the now empty pockets with the new ones. What this does is place bigger than original battens throughout the entire sail. The purpose of tapering all of the battens is to get them to fit into their new but smaller than original pockets. Tapering existing battens and leaving them in their original positions only weakens them and causes the sail to be more flexible, not stiffer. From what I gather, the reason for going through all of this effort is to get more speed out of a tired foil. Phil Berman has a discussion on this in his book "the hobie 16 performance maual". It was originaly printed in 1984 but was updated in the '90's.

Thank you to everybody for your contributions to the debate. The message from jornymn is quite elusive to me. In Europe all the battens come from the same extrusion. This means that, apart from lenghts, they are all the same non larger or smaller. This means that their load is incresing from bottom to top because the profile is the same but the lenght is different. The load increasing from one batten to the other is resonably even, apart the one relative to the number one top batten that is far too much stiff.

Summing up all your advices my actual thinking is that is better to avoid tapering the battens, above all if they are used with an old sail, except from the top one that must be treated quite intensively.

There's an excellant article in 'On the Wire' that explains the different sail shapes and how Batten tapering can effect sail curvature.



http://www.west.net/~lpm/hobie/archives/v1-i2/feature3.htm