Current battens- how to use to adjust sail shape?

[simon1228]

TBH, I am a bit "monkey see, monkey do" in this sort of area...

However, in my early days with the'nova I did mess about with batten tensions quite a bit (Having spent a lot of time in larger keel boats, this was natural). Didn't notice any real benefits, so have left tensions untouched for many years, my overriding concern becoming to avoid loss of any battens! I never did shell-out on those fancy batten tension adjuster gizmos.
I never thought to taper or adjust stiffness in other ways.

The issue of the new go-faster battens per-se, I will leave on the original thread, so as not to confuse things, hopefully...

Q:
Given the concerns of some about the perceived "unfairness" of the new tapered battens, and some details of more basic mods (already undertaken, and "history" to some) leaking onto the new battens thread, could one of the Associations leading hands perhaps post a simple "how to" explaining how/what they have done to improve sail-set utilising original battens?

This "budget option" might also have the added benefit of reducing any perceievd unfairness for those on a more limited budget/unwilling to pay allegedly premium prices for the new parts?

I was about to order new battens, when news of the sail material changes (and associated discount offers - Thanks HB!) reached deepest darkest Cornwall; therefore I will now hold back until the compatability issue new/new is confirmed as positive, by someone who is more competent than me, and ideally without an accompanying sales pitch.
I have several sets of "spare" battens in old sails, and would like to try to explore the budget option asap; I really don't want to (try to!) reinvent any wheels, I don't get enough time on the water to be able to do that!

Thanks!

[CliffMilliner]

Hi,

I'm prob not the best person to post on this subject as I'm not a sail expert in any way at all, so with that caveat read on at your peril. These are the things I've seen tried over the years.

Batten tension:
The main goal here is to remove any wrinkles that you can sometimes get in the sail on the batten pockets. I have mine done up just tight. Personally I find it hard with just the bits of string provided to do them up any tighter, unless you have 2 pairs of hands. I do try to keep the top ones not as tight as the lowers just to help them pop to the new side easier.

Budget tapered battens: idea is to force the batten bend further forward.
For this you will need a few spare battens. The idea is to make the back edge of the bottom 2 or 3 battens stiffer to force the bend further forward.
I don't have my sail to hand to measure the cut lengths need, but they would only be a rough guide anyway. I would think you will need to cut your spare battens so you have somewhere between a 1/4 to a 1/3 of the length of the batten you are trying to taper.
Then tape or glue them to the back end of the batten you are tapering. I left the batten end on as well so I could tie them both into the pockets so I know I will not lose them.

Stiffer battens:
This just makes sure the sail shape is held better by the battens, not sure of other benefits.
Option 1: Get an extra set of battens and put them in the sail so 2 battens per pocket.
Option 2: Some tent pole manufacturers ( the dome tent type not frame!) can supply lengths required at a reasonable price.
Option 3: Find stiffer battens from some other sail and cut them to length.

Hope that helps
Cliff
1190

[Pete1177]

As Cliff suggests, setting the batten tightness is simple and is just a matter of taking the wrinkles out. There's not much else you can do with the standard battens to improve sail shape.

If you want to make 'budget' tapered battens, this is what you need to do assuming you have spare lengths of battens.

1. Measure the length of the battens. The 'nova has 5 battens all non tapered so the maximum draft is at 50% of the length.

#1 (top) Length = 900mm ... no need to do anything with this - leave 'as is' (not tapered)
#2 Length = 1480mm
#3 Length = 1930mm
#4 Length = 2280mm
#5 (bottom) Length = 2530mm

2. Now you need add stiffening to the 4 lower battens to force the maximum draft to the 45% length from the luff. This will be a bit trial and error using electrical tape. Lay the batten on a flat surface and compress the batten to the 90% length. Mark the point of maximum draft and add or remove stiffening at the leech end to get the correct max draft distance from the luff.

Batten #2 (45% = 1330mm), Batten #3 (45% = 1740mm), Batten #4 = 2050mm, Batten #5 = 2280mm

2. Ideally you need to measure the compression force of your new stiffened battens. You will need some digital kitchen scales and something to stand on. Put the 'tapered' battens with the luff (thin) end down and zero the scales to negate their weight. Compress the batten so that the length is the 90% point. Read off the pressure on the scales. Hopefully you will get numbers similar to those below. They needn't be exact but you want to get reasonably close if you can. The numbers in brackets are the standard untapered batten pressures as supplied by HB (on my sample).

Batten #1 (unmodified standard batten @ 810mm) = 1250 gm
Batten #2 = 975 gm (430 gm)
Batten #3 = 450 gm (225 gm)
Batten #4 = 300 gm (120 gm)
Batten #5 = 420 gm (75 gm)

You can see that you are trying to achieve a lot more leech stiffness in the bottom battens. The standard bottom batten is very floppy at only 75gm and we are increasing it significantly as this it where a lot of power is generated. This will stop the leech hooking with mainsheet tension, improve the airflow off the back of the sail and prevent it stalling (losing power) in strong winds. Also remember that if you have an older sail, the draft will move aft as the sails age, so having the battens force the max draft back to 45% will help a lot. The standard battens are very floppy in comparison.

If all this seems too much bother, I am getting a set of cheaper tapered battens which I will test during September which could be made available for about £70 per set .

I will also be testing the new small sail with tapered battens (only 4 battens in this sail) when we get some decently strong winds.

Pete
SN1177

[simon1228]

That's really helpful (and Very prompt!) guys - very many thanks!

I will let you know how i get on....

[Matt]

Hi Simon, Sorry for not posting, been away for a bit. Budget way to tapered battens- do nothing with the top 2 battens, these need to be un-tapered, big misstake if you taperer theses. Use some existing 'old' battens out of an old sail. Bottom batten tape another batten to it about 60% of it's length from the leach. 2nd batten up 50% from the leach. 3rd batten 40% from the leach. DO NOT TAPER THE TOP TWO. This will make a big improvement to the standard battens.
Hope it helps, Mat.t

[simon1228]

Many thanks for that Matt; very helpful; I will give it a try...eventually!

I have also been away, that and also not then having access to a PC (only Android devices - that seem not to like all of the functionality of this forum software!)

I have also asked about the compatibility of new battens with the latest new sail materials/cut/sizing (at thread, here - "Battens").
Can you please advise?

[Simon_Ludkin]

I'm wondering if adhesive lined heatshrink sleeve will work as a stiffening layer for standard battens.

It's waterproof so none of the problems with tape wrappings becoming unstuck and jamming up the batten pocket.

I had the downhaul applied almost a far as it would go on Monday and the luff was notably creased. (posted pic on facebook page)

[Sunsetstrip]

I have one of the new small sails. In a F3-4 it seemed to set brilliantly and the boat was much better balanced than with the full rig. A number of Solo/Phantom sailors commented on how well the sail set, looking more efficient than the full sail. May not, therefore be necessary to amend the small sail battens.