I have an '85 Nacra 5.2 that I picked up last year. No matter what I do, I can't flatten the mainsail anywhere near the other multihulls that I'm racing against (none are nacras). I've tried downhauling harder (6:1 purchase) and sheeting in the main (7:1). Also tried waxing the leach while hoisting the main.

Any ideas?

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Pairajacks
1985 Nacra 5.2
Corvallis Oregon
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you didnt mention outhaul which is used to flatten the lower 1/3 of the sail...

Also, what does waxing the leach do? do you mean the luff (inside the track) so the downhaul with have less resistance?

might be time for a new sail if the depth (pocket) is too much to controll. the sail is probably blown out (stretched)

I have similar problem with older sail & am in process of adding carbon fiber strips to middle battens to make them much stiffer. Pete

It is probably a blown out sail like everyone is saying but there is a bit more you can do.

First thing on the 5.2 is the outhaul as much as you can. You should have 4:1 purchase on the outhaul. Next

Try loosening the diamonds a bit (so you can push them to the mast about 8" to 10" from the bottom. With a stock 5.2 you can't bend the mast back on its major axis to flatten it so you need to allow the mast to rotate and let it bend back on the minor axis. With the loosened diamonds you downhaul as much as you can with the 6:1 to bend the mast over and take the belly out of th sail. Don't do more than 6:1 with an older sail or you are likely to rip it and your halyard cable.

With a new sail, you can add more downhaul, but you probably would't need to.

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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Tie your battens just tight enough to take the wrinkles out of the batten pocket but no tighter. The tighter you get them the more draft is forced into your sail, and it cannot be removed by other controls, just moved fore and aft.

Otherwise, mast rotation will help the most if you can control the degree of rotation, but you are really just moving the position of the draft set by the battens and the overall condition of your sail.

Baggy conditions are why people buy new sails. This from a guy whose main is 25 years old. :)

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Sheet In!
Bob
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Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
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klozhald

Baggy conditions are why people buy new sails. This from a guy whose main is 25 years old. :)

around here.. it is usually due to a main that has ripped well beyond repair. We sail em till they shred. I have 2 mains on life support currently.. the end is near ... same with both my jibs

Thanks for all the feedback!

1. Yes, I have tried waxing the leach to reduce friction on the downhaul, but it doesn't help much
2. The outhaul is pulled out to the end of travel
3. The mainsail is in good shape; no tears and other sailors have remarked how good they look. Minimal thread damage. The fellow I bought the boat from said the sails are new 5 yrs ago
4. It has foam battens. A couple were broken near the mast (fixed all but one). The battens-given the cost of new ones are probably original.

I'll try the idea about reducing the diamond tension and reducing the batten tension. Is there such a thing as a light wind mainsail (one that is made with extra curve to produce more of a shape?) Thanks

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Pairajacks
1985 Nacra 5.2
Corvallis Oregon
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Mainsails are always designed with a certain amount of shape in them based on thier purpose. I have a stock Elliot Pattison Mainsail for my 5.2 which was obviously designed as an all round sail for the boat, moderate belly in the sail. My Whirlwind flattop is made with lots of shape and provides almost unlimited power, very scary in high winds. The sail I got with the boat was made by a tarp maker copied from the EP sail, unfortunately he didn't know anything about sail design so didn't put any shape into it, it is almost dead flat. The flat sail works fine, but is certainly less powerful than the other 2. Jibs are almost dead flat also.

If you want my flat sail I can make you a good deal, just realize that it is very flat and made from 4 oz dacron instead of the usual 5 oz. I've been trying to get rid of it for years.

Regards,
Dave

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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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1. Yes, I have tried waxing the leach to reduce friction on the downhaul, but it doesn't help much

The leach is the back (aft) part of the sail.. you probably mean luff (the front that goes in the track)..

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3. The mainsail is in good shape; no tears and other sailors have remarked how good they look. Minimal thread damage. The fellow I bought the boat from said the sails are new 5 yrs ago

Age and thread do not always indicate overall condition. It is obvious when and why a 20 year old sail is blown out... it's old and used but a brand new sail can be taken out sailing and get caught in a storm with 30-40mph wind and get "blown out". This is when the cloth stretches and deforms it's shape (and doesn't rebound back) and can change the dynamics of the sail greatly.

If you are racing on a pro (or close) level.. .this is critical and this sail goes to goodwill (or a buyer of second hand sails, like me). For weekend warriors.. it doesn't really mean much except your ability to flatten/point may suffer a small amount... who cares..

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4. It has foam battens. A couple were broken near the mast (fixed all but one).

Were you sailing with a broken batten? or with an empty batten pocket (sleeve)? both would effect performance
PS -I would (personally) be worried a broken batten in the sleeve would likely rip through a batten pocket, sail or both... i wouldn't sail with a broken batten.

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I have an '85 Nacra 5.2 that I picked up last year. No matter what I do, I can't flatten the mainsail anywhere near the other multihulls that I'm racing against (none are nacras).

shoulda mentioned this off the bat: other sails / boats may be flatter by design. modern cats have much different sails than mid 80's. apples to oranges never give real results (IMHO). I try to avoid using other model cats as a gauge for my sailing..

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Is there such a thing as a light wind mainsail (one that is made with extra curve to produce more of a shape?) Thanks

More common for casual beach cat sailing is a set of high wind sails (less sq footage, pin top, etc)

You can have as many specialized sails as your wallet will permit.

Pro racers are typically required to submit 1 set of sails (main/jib/spin) for a regatta and must request to replace a broken one... *(varies by race). Some class rules only allow 1 new set of sails every few years for racers to keep it more level and not a $$$ game

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I'll try the idea about reducing the diamond tension and reducing the batten tension.

the first thing i would do is .. get all battens fixed, and check the batten tension as prescribed above..



Edited by MN3 on Jul 25, 2012 - 11:19 AM.