Old Sail Repair: Keep Slats or Install a Luff Line ?

[theller]

Hello,
My google searching has run dry, which normally means I don't know what the hell I'm talking about

Anyway, I have my first lady in the water and I'm preparing to move to the next.. more to the point, I decided to try and run full sails on a 20mph day in my 23' south coast shoal keel. Well, main sail got a little whipped around and some stitching gave loose on it. I have got it pulled off to do some sewing repair now.

Now, the sail currently has pockets for slats to prevent lufting, but the sail is a bit streched due to the way they have caused the sail to run. I have seen other sails with luft lines installed in the trailing edge of the main sail. it seemed to be a cord from top to bottom that you tensionsed in with a locker to put shape to the sail. Guy called it a luft line.

Would anyone have any recommendations on installing a luft line vs repairing and reinstalling the slats?

[Jim Cate]

G'Day theller,

First, the "slats" are usually called battens, and if the sail was designed to have them, you should not abandon them. Their purpose is to support the roach of the sail... that is the portion of the sail that is aft of a straight line from the headboard to the clew. If you leave them out the sail will never set properly -- the leech (trailing edge) will just flap about uselessly.

The "luft" line is usually called a leech line, since it runs down the leech. It too helps control the shape of the aft portion of the sail, and can help keep the areas between the battens from flapping. Installing one might help keep an old sail going for a while longer, but really, once a sail is stretched out of shape its days are numbered.

IF you can afford it, a new main would likely improve your sailing experience quite a lot. If dollars are in short supply it is often possible to buy used sails in quite good condition, and at a huge savings to you.
There are a bunch of used sail lofts which can be located via Google. One that I have used long ago is Bacon & assoc in Annapolis.

Hope that this helps, and good luck.

Cheers,

Jim

[MarkSF]

The installation of a luff line, and the presence of the battens, are not mutually exclusive.

They don't do the same job either - the luff line tensions the luff only and stops it flapping. The battens help with sail shape over the aft part of the sail.

Did you have a problem with the luff flapping? It can happen in old sails that have lost their shape a bit. The luff line helps stop it.

Another thing that would help with sail shape for stronger winds would be a cunningham so it might be worth adding a cringle for one if it's not there already.

I don't see any reason to take the batten pockets off though - in fact I'd look for some battens for them.

[theller]

From the sounds of it I will be adding the luff line as I repair the sail as well as getting the battens installed again. The originals were wooden so I believe I'll cut another set from mahogany.

What is a cunningham?

The boat does have a roller furling for the boom... If I had more sense it would have been furled quite a few feet.

[Jim Cate]

Originally Posted by MarkSF

The installation of a luff line, and the presence of the battens, are not mutually exclusive.

They don't do the same job either - the luff line tensions the luff only and stops it flapping. The battens help with sail shape over the aft part of the sail.

Did you have a problem with the luff flapping? It can happen in old sails that have lost their shape a bit. The luff line helps stop it.

Another thing that would help with sail shape for stronger winds would be a cunningham so it might be worth adding a cringle for one if it's not there already.

I don't see any reason to take the batten pockets off though - in fact I'd look for some battens for them.

Mark... are you sure that you don't mean a LEECH line?

Jim

[theller]

While on subject.. I am going to be repair my bermuda sail also.. Its a bit ratty along the trailing edge.. any advice on the repair work?

[MarkSF]

Originally Posted by Jim Cate

Mark... are you sure that you don't mean a LEECH line?

Jim

Oh yes, good point, I did.

A leech line is what you need to add.

[Blue Stocking]

Jim,

I'm tempted to jump in here and describe an "authentic" Bermuda sail, ( hint-it is not a Marconi rig sail)--but I think I will stay out of this one

[ozskipper]

Originally Posted by theller

Hello,
My google searching has run dry, which normally means I don't know what the hell I'm talking about

Anyway, I have my first lady in the water and I'm preparing to move to the next.. more to the point, I decided to try and run full sails on a 20mph day in my 23' south coast shoal keel. Well, main sail got a little whipped around and some stitching gave loose on it. I have got it pulled off to do some sewing repair now.

Now, the sail currently has pockets for slats to prevent lufting, but the sail is a bit streched due to the way they have caused the sail to run. I have seen other sails with luft lines installed in the trailing edge of the main sail. it seemed to be a cord from top to bottom that you tensionsed in with a locker to put shape to the sail. Guy called it a luft line.
Would anyone have any recommendations on installing a luft line vs repairing and reinstalling the slats?

Leave the battens (slats) in. They are there to hold shape in the sail. A leach line may assist in removing any flutter. But without seeing the sail in action, its hard to say so with certainty. Your best option will be to get a good sailmaker to have a look at it for you.

If your friend doesnt know a leach line from a "luft" line (of which there is no such thing) , stop taking advice from him.

The next step is to make sure you know how to reef the sail properly to prevent future damage to the sail- let alone the rig.

good luck with it...

[ozskipper]

Further to that, a leech line on an old sail may induce windward curvature of the leech, stalling the trailing edge of the entire sail in which case it would be more efficient to trim a little of the leech off if it is flogging. But,as mentioned in my previous post, get a sail maker to look at it.

[ozskipper]

Originally Posted by theller

From the sounds of it I will be adding the luff line as I repair the sail as well as getting the battens installed again. The originals were wooden so I believe I'll cut another set from mahogany.

What is a cunningham?

The boat does have a roller furling for the boom... If I had more sense it would have been furled quite a few feet.

A Cunningham is an eye in the sail. Just above the tack that allows you to add tension to the luff of the sail. More tension in heavy winds to depower the sail and less tension in light winds to add power.

http://womeninsailing.files.wordpres...pg?w=500&h=812

[Cheechako]

Battens need to be fairly thin and flexible, so if you make your own, be sure to round all edges and ends and make them not over 1/4 thick max.

[theller]

Unfortunately we are hours from any sail maker here in southern Illinois. I get to enjoy an inland lake here that's just enough to make a sail boat fun.

I will provide the best description I can of the sail and its action. It is an original main, probably 40 years old now. It had original battens but one of the sleeves had torn free (the stitching had un-let itself). I did have a chance to run it with the battens (3 remaining). Prior to the battens luff was bad in the sail. With them in you could see that the luffing had ceased in about 60% of the sail edge but the middle section between the battens was still lufting at about 40% of what it had prior to the battons installation.

Now, forgive me for taking and creating my own bad advice. The boat was free, I hadn't sailed before... but I said, "f it, I'm gonna learn how to sail". I did manage to flog the sail pretty hard yesterday and it was a good set in of reality.

I may be no sail maker.. but I am about 90% done with a mechanical engineering degree, I think I may be able to do a repair here. It is all built on schematic afterall.

It is obvious that my sail is stretched. I have a half cocked idea of how to take the thing apart and resew with factory dimensions in mind but perhaps someone has a better sail surgeon idea than mine.

I have a commercial machine at my disposal. Perhaps I can resew my seams on the sail and take the stretch out? I am a student, time is my friend.. not money. Call it preparation for desperation in the VI.

Any suggestions taken.

[ozskipper]

Make sure the battens you use are flexible and not too thick. As someone else posted, ensure the edges are rounded for obvious reasons. They are usually made of fibreglass these days. Ebay or google might be able to help you out with the right alternative.

[theller]

I'm pretty crafty with a table saw. I'll take some pictures of the repair progress so you all can critique as I go.