Sail Trim question

bodland · #1 (**permalink**) 06-18-2001

In heavier winds 18 plus knots with a 110 high aspect working jib the leech about 1/4 the distance from the head flutters while close hauled.

I have tried adjusting the leech line (this helps some but looks like it scoops shape too much) and the fairlead forward to put more downward pressure on the leech but in a strong puff I get the flapping. I did find that I was able to put a bit more tension on the jib halyard but still had the fluttering.

I am now suspecting headstay tension. Does this make sense? the sail is a converted hank on to furling sail with North Aeroluff treatment (zipper pouch luff treatment). I think the sail could be furled just slightly and this would eliminate the flutter.

Any thoughts would be appreciated...

paulk · #2 (**permalink**) 06-18-2001

Sounds like you''ve tried all the right moves, (though moving the leads forward as the wind picks up is not generally seen as fast) and now it''s time to call Omar the Tentmaker over to see if he can''t recut the leech a little bit. Also, IMHO that if the headstay (sagging) was the problem, the flapping would be over the entire leech, not just a small part, as you described. Maybe Omar can confirm this for you.

cditzen · #3 (**permalink**) 06-19-2001

Hi,

seems like you''ve gone through all the obvious things to try. I also agree that moving the fairlead forward should help, but on the other hand will likely overpower you, since you really want to spill wind at the higher airspeeds. Maybe the sail really has seen the best days pass?

One thing to consider on a new sail, or maybe your sailmaker can retrofit this one, is to put a couple of battens into the sail. My new #3 has them, and they seem to work fine. The only limitation with them is that battened headsails and furlers don''t like each other ;-).

...Chris

bodland · #4 (**permalink**) 06-20-2001

Thanks for the responses, I was out last night the wind was calm for a half hour and then picked up to about 15 knots. THis time I had the fairleads all the way back on the track and encountered none of the flapping until extremely close hauled. (I would say luffing) However, I don''t think the wind was quite as strong as other time out with the flapping. But I have not had the faileads that far back before.

Fairleads back mean flatter sail or is it the other way around?

paulk · #5 (**permalink**) 06-20-2001

Moving the leads aft tends to flatten the leading edge of the sail and helps keep the curve of the sail where you want it in higher winds. A flatter sail also creates less heel than a full one. (Think how you''d heel sailing upwind with a spinnaker pulling you over vs. a genoa with the same area.) Moving the lead forward creates more curve in the sail - not what you necessarily want in heavier winds - and tightens the leech, which you noticed can cup it, creating bad airflow. Adding battens would be cheaper than a re-cut. Taping a batten in place would let you see how one might work until it blew off. Sounds like you''re getting some good sailing in!

bodland · #6 (**permalink**) 06-20-2001

Thanks again. I think the sail should be okay for now as it looks like it was recently re-cut. Moving the leads aft did seem to be the solution I was looking for. I was likely confused that the downward pressure would flatten the sail as the lead moved forward.

As for getting in good sailing yes I have been. This summer is stacking up to be loaded with sailing. Have done one 62 mile round trip weekend cruise, two weekends with day sails, wednesday night racing and now I''ve added a tuesday after work 2 hour sail.