The cut of my jib questions

Roadking Larry

Roadking Larry

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Mar 30, 2013
700
Allied Seawind MK II 32' Oologah Lake, Oklahoma
My 1976 Cal 2-27 came with 2 head sails. A smaller jib, probably 110%-ish for the boat and a much larger "drifter" which is at least a 150. The smaller sail is fresh from Sailcare and is nice and crisp and seems to be in very good shape. The big one is a much lighter weight cloth and has one well done repair.
I have no idea if either of them are "right" for the boat but seem to be OK.
My question involves the luff length. The boat is a mast head rig. If I hoist either sail all the way up I'm as much as a couple of feet from the fore stay chain plate and the tack of the sail. I just tied on a pig tail to the tack that gets the foot of the sail just over the bow pulpit.
I kind of like being able to see under the sail but am I trading too much performance for that?
Which will give the best compromise, all the way up, tack down on the deck or somewhere in the middle?

Thanks.
 
jepomer

jepomer

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Jan 22, 2008
507
Catalina 310 278 Lyndeborough NH
A smaller foresail does not have to be brought all the way to the top. But bringing it to the top could expose the sail to more of the wind - which you may or may not want to do in different situations.

My Cape Dory 25 has a 110 Jib cut like that. It looks "small" for the boat but is how the designer did it. I do like to raise mine enough to clear the pulpit and life lines.
 
Jackdaw

Jackdaw

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Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
Extra jib luff room is normally left on top, often on sails designed that way with a short wire pendant. On your boat the performance will not be much different with the exception of the CE being raised. The real thing to look for is making sure you can get correct jib lead angles with the sail on the position you choose.
 
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dlochner

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Jan 11, 2014
12,721
Sabre 362 113 Fair Haven, NY
The jib is generally attached to to the stem head at the tack. The sail will not go all the way to the top of the rig, even with a masthead rig. Part of the reason is geometry. There needs to be enough room at the top of the forestay for the sail to tack through the forestay triangle without too much restriction. If the sail was not designed to go to the masthead there will be too much sail to pass through the foretriangle easily.

Next geometry issue. As a rule of thumb the jib sheet lead should bisect the angle formed at the clew by the foot and leech of the sail. Raising the foot of the sail will affect that geometry and you will not be able to properly trim the jib, which affects sailing performance and enjoyment.

Third, raising the foot of the sail and the overall height of the sail will move the center of balance and center of effort higher making the boat tippier. And even the few extra pounds of sail higher on the mast will make the boat less stable. Think of all the leverage you get at the end of a 25 foot mast.

If you want to see forward of the jib, have a sailmaker add a window or have a new sail made that was designed to have a higher foot. Offshore boats will do this so that green water does not get trapped by the sail.
 
G

Gudenuph

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Aug 4, 2009
204
Oday 25 Olympia
Reading this thread raises some other thoughts such as a short luff jib might allow additional trimming options.
Raising the jib up the forestay would have the effect of moving the sheet lead forward reducing twist in the upper part of the sail. This may be desirable when off the wind and/or on the wind in very light air, when due to wind shear, the only wind is aloft.
Winds above 6-knots create a turbulent boundary layer providing less variation of wind velocity with height. The 'deck sweeping' setting could then be used on the wind to lessen the vortex drag under the foot of the sail.
This may be a bit 'over-the-fence' but talk's cheap-----takes money to buy whiskey!
Gudenuph
 
IainB

IainB

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Apr 14, 2009
16
Catalina 30 Semiahmoo
I would not change the size and therefore shape of the sail, it will effect the performance and ability to point. IF I need to see beyond the jib I will often steer from the low side, if seeing past the foot of the jib is really that important to you have a clear window added at the foot of the sail.
 
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Bob Peterson

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Mar 18, 2014
1
Catalina Catalina 22 St. Clair Shores, MI
I used to sail the intracoastal waters near Padre Island Tx. I used a 12 or 14 inch cable to raise the jib for visability in congested waters. Saw no sailing performance changes at all. Some of those power boats needed to be kept under a watchfull eye!
 
B

bffatcat

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Jun 8, 2004
853
Pearson 26W Marblehead
jib height off deck

Listen to dlocner: most boats are designed to sail with the jib tacked down near the deck. The reasons are in dlochner`s post. My boat came with a sail plan from the designer A working jib
and a 125 genoa I did have a 150 genoa but when it wore out I never replaced it. Your 110 is pretty much a working jib. You will probably need a larger jib for lighter air. What you choose is up to you. Cut it high for better visability or have a window installed
 
Roadking Larry

Roadking Larry

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Mar 30, 2013
700
Allied Seawind MK II 32' Oologah Lake, Oklahoma
Thanks folk. Gives me some more to think about and some more experimenting to do.

We had some real light wind Saturday and I ran up the drifter. Which is what prompted this thread. I had noticed that the sail had been discolored where it had previously been repeatedly rubbed against the bow pulpit. I tied on a pig tail to get it above the pulpit and I was able to get pretty good shape out of it playing with jib lead angles and was running down and walking away from other similar size boats that were out.
 
Charlie Jones s/v Tehani

Charlie Jones s/v Tehani

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Mar 1, 2012
2,182
1961 Rhodes Meridian 25 Texas coast
I would never dream of sailing a short handed boat (non racing ) with the jib tacked down low. ALL of my jibs are on a pennant. The VERY slight loss (if any) is MORE than made up for by the ability to see AHEAD of you, UNDER the jib.

My ex once towed a dinghy completely over the top of a nun buoy she didn't see. Since then, pennants on all of them, no question about it. Matter of safety in crowded waters
 
D

david gearhart

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May 24, 2012
1
coronado sailboat napa, ca.
An answer that might help

jepomer said:
A smaller foresail does not have to be brought all the way to the top. But bringing it to the top could expose the sail to more of the wind - which you may or may not want to do in different situations.

My Cape Dory 25 has a 110 Jib cut like that. It looks "small" for the boat but is how the designer did it. I do like to raise mine enough to clear the pulpit and life lines.
Click to expand

I own a Coronado 32ft sloop with roller furlong foresail. I believe your boat will sail better with your sail all the way up. The winds are stronger and it should balance your boat better. My experience is to always use the sails that are designed for the boat. I got the wrong main when I bought my boat and was told it was like runnin with the main reefed a little. Not true. It sailed finr but after I replaced it with the right one, it gained 2 and 1/2 knots to my sail speed, not to mention a smoother ride. Hope this helps. David
 
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