Have a new boat project

Discussion in 'Sailboats' started by thefuture, Nov 14, 2008.

  1. thefuture
    Joined: Mar 2007
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    Location: michigan

    thefuture Junior Member

    I have obtained a boat hull that is in need of a rig and a new daggerboard. The boat is a Santana 23d. I have owned one of these boats in the past and absolutely loved it. The boats have an inherent problem with weather helm. While i am doing all this work i figure i might as well turbo the boat. I am looking to put in a Melges 24 rig with a cut down boom. I was wondering if i move the mast step forward or aft can i help the weather helm issue? I am a semeseter away from an engineering degree and have done a fair amount of boat work in the past so this is a job i can accomplish. I do know that i will have to move the bulkhead as well and having owned a santana 23d in the past am not afraid of the job. thanks.
     
  2. Seafarer24
    Joined: May 2005
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    Seafarer24 Sunset Chaser

    Moving the mast forwards would help, or putting a sprit on the bow and simply moving more sail area forwards. The better fix would be to add some lateral resistance to the aft end.
     
  3. thefuture
    Joined: Mar 2007
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    thefuture Junior Member

    Lateral resistance to the aft end?
     
  4. gggGuest
    Joined: Feb 2005
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    Location: UK

    gggGuest ...

    I reckon there are at least three different features of boat handling that folk describe as weather helm, and which you have affects what you should to to mask or cure it...

    1) going along with the boat bolt upright the tiller has to be deflected to windward to make the boat track straight.

    2) going along with the boat bolt upright the tiller is pulling on the helm, but still on the centreline.

    3) the boat tracks fine when upright, but the more she heels the more she tends to push up into wind, and the tiller must be pulled up to windward to keep her on course.

    1) is probably the good old classic of the sails turning the boat, and the moving the rig forward and/or the keel/centre of lateral resistance aft will almost certainly help.

    2) may well not be a problem, especially not if its an unbalanced rudder. This is fashionable in some of the development dinghy classes, and just means that the rudder is sharing the sideload with the board. Provided the tiller is on the centreline there's no extra drag.

    3) basically means that you have a boat that needs to be sailed upright! you could I suppose mess around with moving the sail plan so you get less weather helm at a given angle, but logically this means you will be getting into lee helm when bolt upright which may not be desirable!
     
  5. thefuture
    Joined: Mar 2007
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    thefuture Junior Member

    Number #1 is my problem. The boats inherent problem infact. All santana 23d owners have complained of this. Moving the centerboard box aft would require a lot of work but i am not counting that out. Moving the mast forward may be my answer.

    My next question is the boat does not have a rudder. I understand the process in making the rudder and have in mind what i want to do attatchment wise.

    What do i need to look at in order to figure our what size and NACA shape i want the rudder to be? I'd like to get started on this project. Thank you!
     
  6. gggGuest
    Joined: Feb 2005
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    gggGuest ...

    The simplest way to get that balance is probably to take area off the leech of the mainsail and add it to the luff of the jib. A bowsprit is OK, so would a false bow be... This shows a false bow being added to a rather smaller boat.
    http://www.sailingsource.com/cherub/test/lib/exe/fetch.php/tech/2641-2000snoux.jpg. Much more work than a bowsprit but gives quite a modern look if that suits the rest of your boat. Doing a photoshop impression on a photo - maybe like this, might tell you whether you like the idea: not sure a sprit will suit your boat. If you're on a budget you could possibly get away with cutting a trioangle off the bottom of the jibs and moving the clew up to cope with the more angled forestay rather than buying new rags.

    Because boats will track quite happily with rather a lot of the side force on the rudder the sailplan/keel needs to be very out of sync to actually require an offset on the helm when bolt upright. I reckon its a pretty rare phenomenum, folks often mistake a combination of 3 and 2 for 1...
    Either way it will also help you to get the centre of effort aft, so a transom hung rudder if it hasn't already got one is worth considering...

    Rudder size isn't necessarilly that critical provided its big enough. Bigger moves the centre of effort further aft , gives more control, but causes more drag and reduces speed.Should be fairly easy to find out the area of te standard one... Something like a NACA 0012 seems conventional for section...
     

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  7. water addict
    Joined: Jun 2004
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    Location: maryland

    water addict Naval Architect

    Since you need to make a rudder anyway, you could hang a larger outboard rudder off the stern. That would move CLR aft and might be a more simple fix to balance the boat than moving around the bulkhead and mast, or making a bowsprit.
     
  8. thefuture
    Joined: Mar 2007
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    thefuture Junior Member

    Extending the bow is out of the question. I am going to add a sprit but that is for the assymetrical spinnaker. Cutting up the sails would negate the added performance i am trying for by solving the weather helm issue. Let me give an example i have sailed a beautifully rigged nationals winning j/22 and could almost not touch the rudder going up wind it was so balanced. The santana 23d's that i have sailed all require significant effort at the helm to keep the boat from rounding up, hence drag and reduced performance. This happens on with varying sails up; The 105% 135% and 155%. I think for me the best situation will be to move the mast forward about a foot and/or the daggerboard case back about a foot. I want to keep weight out of the ends of the boat so i will be building a rudder from carbon with a carbon cassette so it can be raised while sailing to reduce wetted area downwind and keep it's beachability. I'll start a new thread with pictures when the process begins. I will also be building new sails to match the new rig and will work with the sailmaker to solve this problem as well.
     
  9. Stumble
    Joined: Oct 2008
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    Stumble Senior Member

    Thefuture,

    Moving the mast forward a foot is extreme. Normally mast movements are made an inch at a time or smaller. On my Olson 30 I build a rig that allowed me to move it by turning a bolt just so I could get small enough changes. If the helm is really heavy I would recommend moving it forward two inches or so and see how that balances the boat before making any more drastic modifications.

    Once you get the mast in place you will also need to consider recutting the jibs for the different rig dimensions, and play around with the shrouds since you will be changing the measurements from the chain plates to the mast.
     
  10. thefuture
    Joined: Mar 2007
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    thefuture Junior Member

    Ok your right a foot is quite extreme so i won't do that. I am going to build all new sails for the boat anyway so the cut won't be a problem. I am considering going to swept spreaders and moving the chainplates aft further anyway (any ideas?). I'm also thinking a Melges 24 rig may be a good way to go.
     
  11. mattotoole
    Joined: Nov 2004
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    mattotoole Senior Member

    I crewed on a Santana 23D many years ago and we found the hot setup was to rake the mast forward. I don't remember how much. I've since heard that some later boats were built with the daggerboard moved a bit to balance the helm. I don't know where I heard that or if it's even true.

    With a different (M24) rig you need to find its center of effort compared to the original rig before you start moving the mast around. My guess is that the bigger roach will move the CE aft.

    This is a neat boat that's dying for a carbon mast, let alone the extra horsepower. Good luck with your turbo project.
     
  12. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    The common practice with the Santana 23 is to adjust mast rake, have well cut sails and supply her with a new rudder (if necessary) with slightly more area in the right places.

    This boat is designed to use big headsails. If you're using small headsails in light to moderate winds, then you'll experience some weather helm. It's also sensitive to sail draft, requiring good cut and set or you'll experience a heavier helm.

    Since you have to make a rudder anyway, you're options are wide open.

    I wouldn't consider moving the mast. The boat can balance if tuned properly and has good sails. I also wouldn't recommend a Melges 24 rig on her. The 23D is a nice little boat, though additional horse power is desirable, putting this rig on her is an especially hard way of going about it. Hoist a big *** spinnaker off wind and carry the 150% as long as you can. This boat isn't built for much more strain then the current rig can exert on it.
     
  13. Steve W
    Joined: Jul 2004
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    Steve W Senior Member

    I just did a similar project,namely putting a J24 fractional rig on a C&C 24 which originally had a masthead rig, not exactly turbo though as under most sail combinations there is now slightly less area but the boat sails very well and balances perfectly under any combination,even full main only in high teens gusting to high 20s.
    I was able to purchase a sail plan drawing which i had copied,then whited out the rig and had more copies done, i figured the clp and then drew the j24 rig on placing the center of effort in the same location as the old rig. I ended up placing the mast 20" ahead of the old location and of course building appropriate structure to support it. Of course we took a horrendous rating penalty,in the one race we did they rated the boat at 183 which is a 37 sec/mile hit, i had lent the boat to a friend who finished the 10 mile race in 6th place across the line out of about 15-20 boats and 5th correctedall the boats ahead were at least 10ft longer and right behing were a new 37 and old cal36. good luck with your project.
    Steve.
     

  14. thefuture
    Joined: Mar 2007
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    thefuture Junior Member

    Yes the santana 23d is a great boat. In later models they did move the centerboard casing back and i may do the same. I have the knowledge, tools, and some experience to build a rudder but am not sure what NACA foil to go with and how long to make it? I think if i went with the melges rig i would cut it down to more closely match the original rig of the 23d. I have never heard of raking the rig forward?
     
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