Question for Joli

[ssullivan]

Ok, anyone can answer, but Joli (IMO) is our resident racer and nobody knows sail trim questions like a racer.

I have this nagging problem with my genoa (110%). It has the wrong "twist" to it when I'm anything from a beam reach to close hauled. What happens is that the top few feet aren't pointing where they should be and are spilling air out. Also, at times I develop a flap in the luff - but only in the last 3-4 inches of the sail, even when the sail is nice and full. I tried moving the track car forward and back and different tensions on the sheet, but nothing seems to work.

It's almost as if I need to pull *down* on the sheet, or put it more outboard or something.

Anyway, who knows the proper way to get that little ripple out of my genoa?

[cat man do]

Has your sail got a leach line? (sting running dwn the back edge of the sale to a small alloy preferably clam cleat)

If so, pull a littl bit on this.

I also had a couple of spots on the cabintop where I coud attach a tweaker so as to get more adjustment to sail shape, being able to pull the clew outboard or more inboard as required.

Hope that helps.

Also a picture may help if possible

Dave

[ssullivan]

Originally Posted by ssullivan

I develop a flap in the luff

Oh, man! I'm sorry... this must have made no sense. I meant leech! The ripple is back by the sheet, running up the leech. Sorry.

I don't know if I can fit this problem into the frame of a camera, unfortunately. I'll check for the leech line, thanks for the tip.

[Ex-Calif]

Not a racer and certainly no shaping expert but...

The primary control for twist is sheeting angle - Forward sheeting reduces twist due to a more "downward" haul.

Barberhauling, Backstay tension and even halyard tension also affect twist. but they also affect power and pointing ability.

I know this is a new rig to you and it might be normal. One of the other Catalac owners might chime in. However the telltales are the key. When close hauled and trimed right all the telltales should stream together. As you slowly head up, all the windward telltales should stall about the same time. If the top one stalls first you have too much twist.

A vertical crease in the leech sounds like there is too much vertical tension. I'd look at backstay tension if it were me. Looser backstay = less twist.

Here is a great primer on Genoa shaping.

Genoa Fast Course

[David M]

Sean,
How worn does the sail look? It may be blown out. A sailmaker can take care of that.

David

[ssullivan]

Got it!

Dan (and others) were right, but mostly Dan called it. It's a new rig to me.

It's very sensitive to car position on the track. I had to put the car approx 3/4 of the way forward on the track. Too far forward meant the sail would touch the spreaders. Too far aft and the sail would luff on the leech like described. 3/4 was the magic location. I had been overshooting it.

Thanks for the input. It was simple and I was dumb... lol

[Joli]

Hello Sean, hope the trip is going well and the bugs are getting worked out. I'm sure you be glad to have her home.

Chances are the jib has gone round. Easy to see with a multi spreader rig, tough to see with a rig that has a wide base like yours. When moving the cars forward watch the luff to make sure they break even, when you crack (ease to reach) the car will need to go forward to keep that relationship. Someone may have had the car too far forward and stretched the leach. With a soft leach, as other have said, you can tension the leach cord but you will have to live with cupping. The best bet is a re-cut when you get the boat home. If the fabric is not to shot you should be able to this a few times before you need to worry about replacement.

Hope this helps.

Joli

[GordMay]

See also, “CREASES”, by Bob Suggitt (Suggitt Sails)
Sail Setting

and the “Sail shape when sailing on a reach” from US Sailing on-line tutorial series:
Sail Shape