how tight is tight in mainsail

Discussion in 'Sailboats' started by RonR, Aug 14, 2008.

  1. RonR
    Joined: May 2008
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    RonR Junior Member

    in a blow of say 15-18knots should the halyard be winched up, or is hand cranking sufficient ?

    With a loosefooted mainsail. I have a 6:1 pulley arrangement for the outhaul (inside the boom). Should the wince be applied here also?

    A little wrinkling appears around the sail slugs. This OK ? What if the whole mainsail was further separated from the turbulating effect of the mast by extending the slug attatchments ?
     
  2. Landlubber
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    Landlubber Senior Member

    From your description of what you are doing, the sail is too loose, there should be no wrinkling on the luff, so yes, winch her up a bit. Too much will put a set of hollow stretches in the luff, so watch for this and do not over do it. It would help if we knew the size, but it is basically the same anyhow regardless.
    A 6:1 tackle on the foot should be enough, but the exact same principles apply anyhow, just horizontal instead of vertical. leave the slugs, they make good contact with the mast and allow easy jiffy reefing.
     
  3. Landlubber
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    Landlubber Senior Member

    A simple tackled downhaul on the sail can also achieve this benefit, you may have to have tapes or and eyelet fitted, but a downhaul is a good trimming method instead of using the main halyard.
     
  4. RonR
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    RonR Junior Member

    Does the downhaul perform the same function as a Cunningham. Also, does it work with the main halyard stretching the luff equally in both directions..?

    Thanks for your reponse

    BTW My flying machine is a MacGregor 26X

    Cheers......R
     
  5. alan white
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    alan white Senior Member

    The downhaul stretches down only.
    I don't know if the MacGregor has a wire halyard, but iy may have only a rope halyard. Either way, it might help if you installed a 3/8" Spectra all-rope halyard. Then you could put a small winch on the mast itself.
    The Spectra rope won't stretch much so you can tension it properly for most conditions beforehand.
    Just guessing but MacGregor is set up cheaply and it probably has a straight dacron double braid 5/16" or 3/8" halyard.
    You should at least examine factory equipment first and make sure it is adaquate before modifying beyond that.

    Alan
     
  6. RonR
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    RonR Junior Member

    I think you are right. double braid and maybe 5/16". From earlier rock climbing days I learned how well Spectra works.
    All my lines come back into cockpit. Just means a few extra feet of Spectra for the halyard. Then maybe a pair of triple blocks for the downhaul I guess...........Am I on the right track?

    Thanks again...R
     
  7. BHOFM
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    BHOFM Senior Member

    What is the age of the sail? When they get old and stretched
    they can be hard to get shaped right!
     
  8. RonR
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    RonR Junior Member

    It is our first sailboat(new 2001) and has been lightely used 'til now. However, as I read ,read & read again about performance I am now pushing the (read, my) envelope.............:D
     
  9. Landlubber
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    Landlubber Senior Member

    RonR,

    Yes the downhaul is the same as a Cunningham.
    Been away for a while.
     
  10. RonR
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    RonR Junior Member

    Cheers and thanks again
     
  11. RHough
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    RHough Retro Dude

    The main luff, the halyard, and the downhaul all stretch. The main luff can be trimmed with either the halyard or the downhaul. If the main sail tack is not fixed at the gooseneck, pull the halyard up until the sail will go no higher and cleat the halyard, use the downhaul/cunningham to do all the adjustment. When the wind picks up and you have enough downhaul on to take all the wrinkles out of the main luff, try to see how far down the head of the sail has moved ... you will be surprised.

    Wire, rope, and spectra all stretch. Wire returns to it's original length after it has stretched, just like a spring. Some rope returns to its original length, spectra does not. Spectra has "creep" it gets a bit longer every time it is under tension, it recovers most of its stretch immediately but not all, over the next few hours it regains some more, but never gets it all back. If you race, and adjust halyard tension all the time (every 10-30 minutes) it is not a problem, for a cruiser, if you take a new spectra halyard and mark it at full hoist and for your reef points, the marks will be wrong after a few days sailing. Wire halyards do not suffer from this, once they are stretched once (to set the lay) any marked settings on the halyard are repeatable.

    As much as I hate splicing rope to wire, I value repeatable settings more, I've taken the expensive spectra halyards off the jib and main and gone back to wire. When you compare stretch to weight, you will find that by the time you get a spectra halyard to match the same stretch as wire, the two weigh nearly the same, there is no real weight gain for spectra unless you want to live with more stretch. Then add the short life of a spectra halyard compared to a wire halyard and unless you are racing and adjusting constantly spectra is a poor halyard choice for most boats.
     
  12. alan white
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    alan white Senior Member

    The splice isn't your average backyard job--- it's a job for a pro rigger.
    Switching to rope/wire, the masthead sheave (I think the Mac is a fractional rig) should be exchanged for a wire type unless it already is a combination sheave that has both wire and rope capability.
    There's some extra nocturnal noise to listen to as well, the slap of wire against the mast. It might be a good comprimise on that particular boat to simply increase the halyard rope size to 1/2" no matter what you use, which would reduce stretch by half or better over even regular dacron, and I think the downhaul should be pre-adjusted with the halyard doing the adjusting underway using a winch and a rope stopper--- therefore the downhaul can be a simple 2:1 with a block on the boom and a cleat below at the tabernacle.

    Alan
     
  13. RHough
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    RHough Retro Dude

    I mostly agree.

    Halyards should never slap against the mast. :p

    As far as adjusting the downhaul or halyard. I happen to prefer to use the downhaul (cunningham). Downhauls are easy to lead aft to the cockpit, when you lead a halyard aft, you increase the length of the halyard that is under tension so you increase the stretch in the system. A powerful, 4:1 or 8:1 down haul system lead aft is much more stable as far as stretch goes.

    If the Mac actually downhauls the whole boom, by sliding the gooseneck down, I'd agree that using the halyard would be better.

    Thanks for mentioning the sheave! I keep forgetting that many newer masts can't use a wire halyard. That limits your halyard choice to what will fit in the sheave, so you may have to use more expensive line to keep stretch under control.

    New England Ropes used to make a very nice parallel core line for halyards (Sta-Set X?). Marlow's Excel is also very good for low stretch dacron line. Both are the devil to splice though. :(

    The PBO lines are great all rope halyards, but at $3-6/ft and a service life of 2-3 years, they make little sense unless you are a hard core racer.

    The key is to what you can easily to reduce the stretch in the system, the sail should be the stretchiest (is that a word?) part of it.
     
  14. alan white
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    alan white Senior Member

    There are many ways to improve the Mac. I think the most practical approach would be to balance all improvements against the rest of the systems on the boat---- meaning all running/stabding rigging (like e.g., replacing go-no go shroud adjusters with turnbuckles).
    Why not add reef points to the sail?
    The Mac, as delivered, is very basic. In this individual situation, it would pay to make a list of desired changes abd look at cost/benefit of each in comparison with the others.
    That's why I mention simple remedies. A cunningham uses expensive blocks, and of course, a wire/rope halyard is an expense that may not make sense given so many other items screaming for attention.
    I don't know if there's a winch on the cabin top already, but if not, I'd wait a while to mount one (though I think it's eventually a good idea). I'd increase the halyard sizes first and make sure the cabin top cleats are large enough.
    The Macgregor design doesn't have a lot of resistance to heeling forces and so it stresses its rig much less than a lot of heavier boats. I'd have two sets of reef points installed and roller reefing for the jib if it isn't there already.
    Just practical ideas to improve that particular boat.

    A.
     
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  15. BHOFM
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    BHOFM Senior Member

    So many times I have seen people spend lots of money to
    improve the sailing performance when all they needed to
    do was look in the cabin and decide if they needed all that
    stuff to survive a week end trip??

    Do you really need eight fenders and four anchors??
    How many inflatables can you live without? Your stove
    has two burners, why do you have three pots and four
    skillets?? Settings and flatware for eight? Going to be
    crowded at that little table!

    Maybe a trip to the gym now and then would help the
    kph as well??
     
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