Dagger board protection

Discussion in 'Sunfish Talk' started by leob1, Apr 27, 2016.

  1. leob1

    leob1 New Member

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    My local lake has a low water level, which mean that the shore is rockier than it should be at the boat ramp. It also means that my dagger board will get eaten by the rocks if I don't pull it up in time(which usually happens).
    I'd like to protect it, after I repair it, to keep this from happening.
    What would be the detrimental effect if I wrap the bottom portion of the dagger board in some type of protective material, like a split rubber hose? Would it effect how the boat sails? I don't race so I don't care too much about speed.
     
  2. fhhuber

    fhhuber Member

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    It will add drag and slow you down.

    It might aklter the flow around the board in a way that makes it somewhat less effective at helping you not get blown sideways.

    IT can prevent you from being able to pull the daggerboard up when you see an object, then you hit and break the hull.
     
  3. JohnCT

    JohnCT Active Member

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    Not to sound rude, but....

    It is your job as the person in command of a vessel, to not hit things too the best of your ability.

    Sailboats are built to sail, because of that, they sort of can't be built to crash, because then they don't sail very good.

    So as sailors we have to be aware of things above and below our boats, as well as what is around us on the water.

    You will find the more you pay attention to what's going on outside the boat, the easier the things inside the boat become.
     
  4. Country

    Country New Member

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    Loeb1 I feel your pain. What you need is not protection for your daggerboard, but a way to keep it elevated when approaching underwater objects. I sail on a northern Wisconsin lake that is full of boulders and rock bars. Total awareness of where you are at is critical. The daggerboard needs to be raised when near underwater objects. Just a few inches below the hull will still give you control of the boat. If your board will not stay up in the raised position you can try several techniques. Some people will attach pieces of carpet in the slot to close the gap and hold up the board. I use a small sponge that is jammed into one side and keeps the board up in the position I need. Sponge is used to clean out cockpit and stays in the boat. I use the sponge all of time, since I very rarely want a fully lowered daggerboard.
     
  5. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    Because leeboards swivel upwards, the solution may be in attaching leeboards to your Sunfish.

    Checking around the Internet, there are no Sunfish examples, but they're commonly seen on canoes, kayaks, and other shallow water boats. Below is an example of a homemade leeboard. There's no reason you can't use a pair of Sunfish daggerboards. You'll need to have a "lever-bolt" on the outside to adjust the tension. One board in the water is sufficient, the other can be raised.

    [​IMG]

    Building A Rig

    The other photo below, taken in 1961, shows my Grumman canoe with leeboards.
     

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  6. signal charlie

    signal charlie Well-Known Member Staff Member

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    If you don't plan to race you could add a thin strip of kevlar or fiberglass to the leading edge and tip. Make sure to sand it so it doesn't bind in the slot.

    The bigger problem with your situation is damage to the daggerboard slot when the board hits something. That can breach the hull and create leaks.

    Once you get more local knowledge, pick the best area to land and go slow. Bring the board up early and hop off before the boat runs aground.

    Cheers
    KB
     
  7. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    I don't have a shallow lake problem, but another member here had Sunfish sailboat customers that were hitting submerged stumps, causing expensive fiberglass repairs to the daggerboard trunk. No feedback was returned to my suggestion, but here it is, again:

    Use a 1/16" stainless steel cable clipped at one end to the bow handle, and the other [submerged] end attached to a screw into the front face (lowest) tip of the daggerboard. (An eye at each end would have to be formed). The daggerboard could still be removed, as long as the bow handle clip was smaller than the inside of the daggerboard trunk. When the cable strikes an underwater obstacle—depending on the speed—the Sunfish should reduce speed and come to a relatively gentle stop, or the board may simply pop up from the force returned from the cable. The 1/16" stainless steel cable is plenty strong and would not interfere with a beach landing, nor affect your speed all that much.
    Some sailing cruisers drag large submerged cables supporting their centerboard's ends.

    I think it would work best if the board wasn't allowed to extend further than the factory's brass tensioning clip near the handle—short, but still "enough board" to sail to windward for recreational sailing. I wouldn't go extra-fancy, just use crimped sleeves to make a tiny loop at the daggerboard end, and another loop for a carabiner at the bow handle end. Sleeves could also be used to splice (lengthen/repair) the cable.

    Fullscreen capture 4282016 54520 AM.bmp.jpg






     

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    Last edited: Apr 28, 2016
  8. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    Like this—after forming a bridle at the bow handle—in red:

    Fullscreen capture 4282016 63231 AM.bmp.jpg
     
  9. fhhuber

    fhhuber Member

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    The line/cable idea would help some... but its got to be pulling the bottom of the board forward under tension when the board is all the way down, and as the board is forced up the line will be less effective. Probably by the time the board is 1/3 of the way up due to the cable , the cable wouldn't be doing much to protect the daggerboard or the hull.

    Change it to the daggerboard being latched down and that cable actuating a trigger to unlatch it and the board being sprung to come up... Then it protects the board and hull from daggerboard impacts.
    This is almost idiot proof... but precludes any proper adjustment by a competent sailor.

    The best solution is a competent sailor watching for obstructions and pulling the board up or turning to avoid them.

    You could open up the belly of the Sunfish and convert it to a swing keel and put a 1 inch steel leading edge on the daggerboard (now a swing keel)
    You end up with a long swing keel trunk invading the cockpit.
    An expensive solution to the real issue of operator error.
     
  10. Wavedancer

    Wavedancer Upside down? Staff Member

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    Damaging the board is something one may have to live with, I am afraid.
    The river where I sail some of the time is full of debris after a major rain storm. As a result, I have had a few sharks take a bite when going at relatively high speed (planing) and hitting under water tree branches.

    Most of the time, the damage to the board can be repaired at relatively low cost (MarineTex etc). Fortunately, the trunk (harder to repair) has stayed waterproof (so far).
     
    Last edited: Apr 28, 2016
  11. Kevin Mc

    Kevin Mc Member

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    Some are making an assumption that the water is clear enough to see an approaching hazard which is not always the case. Where I sail I'm lucky to be able to see a more than a few inches below the surface.
     
    • Agree Agree x 1
  12. JohnCT

    JohnCT Active Member

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    Where I sail I can't see much below the surface either.
    If my hand is the one on the tiller, it is my responsibility to avoid objects in or on the water to the best of my ability.

    Just as if you sail into a fog bank, limited visibility does not change your responsibility to take proper action to avoid collision.

    There are charts available for almost every decent size lake in the country. Most are even online.
    If your going to a new body of water or your new at sailing, look at them.

    And if you know your ramp is low and rocky, then you need to approach slower, raise your dagger board sooner and watch closer.

    A piece of 1/4" bungee cord tied from the bow handle to the dagger board helps to hold in the raised position.
     
  13. E Andy

    E Andy New Member

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    It sounds like to me that you need Navionics+. It includes their SonarChart technology which is an HD bathymetry map with amazingly accurate bottom contour lines so you can tell exactly where shallow waters. And you can adjust your settings to account for your boat's draft, cruising speed, etc. Not to mention they are the most up-to-date charts you can get. I'll never get on a boat again without my Navionics+ mobile app. And the mobile app is great because you can take it with you on any boat. Many of my sailing/boating friends have been grateful that I have that app on my phone.
     
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  14. Webfoot1

    Webfoot1 Active Member

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    What you wrap the board with needs to fit through the Dagger-board slot. About the only
    thing that will hold up to rocks is if you wrap the leading edge in sheet brass like a wood
    airplane prop. Do a image search on the web and you'll get my idea. You may end up making
    you Dagger Board a little thinner than normal to compensate for the extra width of the brass.
    Anyway, no new tech here as this has been done to protect the stem of boats for ages. Still, if you
    whack rock hard enough it will do damage. Water depth is always something you keep in mind,
    that's why my boat props stay dent free while others look like a chewed up mess. I usually
    push my sailboat out till I'm chest deep in water and sail out with the board pulled halfway-up for
    the first 50 or so yards. Do the reverse when returning to the dock.
     
  15. Subsailer

    Subsailer New Member

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    I'm worried about my dagger board when I loan out the Sunfish for friends to try it and take a spin, so I'm just going to make a warning label that they can see and mention the board should be up when returning to shore. The fiberglass strip on the leading edge mentioned before in this thread sounds ok too.
     
  16. Webfoot1

    Webfoot1 Active Member

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    Many people will not lend out boats they own. The main reason is that people
    who are not familiar with how a boat handles tend to make mistakes. Another
    is that it's not their boat and they act accordingly. I'd say if they damage anything
    a wooden daggerboard is the least costly. I'd worry about tipping the boat in shallow
    water and sticking the gaff in the mud followed by running the boat into a dock or rocks.
    Best if you accompany you friends a few times to make sure they have a handle on things.
    I don't think they would object to a few free lessons. Don't forget to have them tie a
    empty milk jug to the top of the mast or gaff.
     

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