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Broken rudder...shield?

Discussion in 'The Cherubini Hunters' started by DanLink, Nov 7, 2015. Add this thread to a FAQ

  1. DianaOfBurlington

    DianaOfBurlington

    Joined Jun 5, 2010
    927 posts, 27 likes
    Hunter 25
    US New Jersey (for now) Burlington NJ
    The astute will observe that Bob Perry disagrees with much of what my dad did, a sore point in this family of boatbuilders and one which I, and others, have taken up with the media often over the years. I won't go into reasons for this quasi-rivalry and shall leave it to Hunter owners as to which side of it I take myself.
    :snooty:
     


  2. DianaOfBurlington

    DianaOfBurlington

    Joined Jun 5, 2010
    927 posts, 27 likes
    Hunter 25
    US New Jersey (for now) Burlington NJ
    Reasonably, for a balanced rudder, you have two options: the skeg and the balanced blade (spade). In both the general idea is to provide 18% of the total area as that before the rudder post. On a spade rudder, this portion actually goes the wrong way, which can add to steering problems especially if the boat is heeled hard over (it will try to lift or bury the stern) and especially if the rudder is angled backwards, such as on my friend's older Pearson and others (upper end of rudder post being forward of the lower end). Olin Stephens criticizes the angled-post spade rudder setup intelligently (as he does with everything else) in All This And Sailing Too.

    The spade rudder is also vulnerable to damage and, when damaged, falling off the boat due to its being hung only by the rudder stock, which has to do too many contradictory jobs: to stay straight, to hold the weight of the rudder, to withstand torsional loads, and to keep out water. Its best advantages are a quickness in steering, preferred by small-keelboat racers (making the boat more like an unballasted dinghy) and simplicity of construction (by cheap-boat builders). That said, the Star, perhaps the most wonderful small keelboat ever, has a skeg-hung rudder (sort of).

    I would prefer my H25 to have a skeg; but the boat was co-designed by Bob Seidelmann who was, indeed, one of those small-keelboat racers (the Star in fact). ;)

    For all sorts of reasons, the better setup is the skeg-hung rudder. It steers more reliably at high angles of heel, is stronger, and is vastly easier to handle when reversing under power! It is somewhat more expensive to build; but, once installed, is easier to maintain and even to repair. In my view it's even more streamlined and thus faster; and it virtually eliminates the likelihood of collecting lobster-pot strings, to which the spade rudder is just about designed to be vulnerable. In my opinion the spade rudder is not meant for serious ocean voyaging; and few serious ocean voyagers will disagree.

    I submit that Mr Perry's suggestion that the boat with the skeg-hung rudder, steered better without the skeg, is only of anecdotal value. Technically the boat should be harder to steer, especially at speed or even at very low speed (fluky conditions). I don't mean that it's harder to turn the helm. I mean that, without either the skeg or the balanced leading edge, the rudder can stall, creating drag but no steering effect. Being raised by my dad who used to teach, 'Steer with authority', I expect the boat to go round when I put over the tiller and I don't see a skegless, unbalanced rudder helping me do that.

    But I allow that much of the evidence for and against may be ultimately anecdotal after all. :banghead:
     


  3. DianaOfBurlington

    DianaOfBurlington

    Joined Jun 5, 2010
    927 posts, 27 likes
    Hunter 25
    US New Jersey (for now) Burlington NJ
    Like I don't have enough to say--

    Rick Moore has some interesting photos of his 'shark-attacked' rudder on his Ambient Real Life series, in which Sophisticated Lady shows one (or more!) of the inherent liabilities of a (large) spade rudder on an ocean-cruising boat.



    The rudder bits begin in this video at about 6:50.

    This guy always has good things to say, being a true salt who uses his boat for business and pleasure and has learned the important lessons about maintenance (as well as about having fun).
     


  4. salas81

    salas81

    Joined Sep 13, 2016
    4 posts, 0 likes
    Hunter 30
    US Milano Marina del Rey
    I have the very same issue: the bottom of the skeg broke and leaves the rudder unconstrained at the bottom. I don't think the skeg is a structural part, but sure enough it prevents the rudder from whipping in case of sideways forces. My question is: can the skeg be removed with the boat into the water?
     


  5. Dalliance

    Dalliance

    Joined Oct 6, 2007
    574 posts, 47 likes
    Hunter 1982 H30 Cherubini
    US Chicago (Burnham)
    The skeg is attached a bit like an external mounted keel; bedded in sealant and through bolted to the hull below the waterline. I think you need to haul out to safely, and correctly, make that repair.
     


    Last edited: Sep 13, 2016
  6. salas81

    salas81

    Joined Sep 13, 2016
    4 posts, 0 likes
    Hunter 30
    US Milano Marina del Rey
    I definitely have to haul it out to do the repair. My question may be wrongly posted: I want to remove the skew while the boat is in the water and then see if I can repair or I have to replace it. I don't want to order it when the boat is out because it takes forever to deliver. So, I just would like to know if removing it while in the water could cause any damage, like leaks or others.
     


  7. Dalliance

    Dalliance

    Joined Oct 6, 2007
    574 posts, 47 likes
    Hunter 1982 H30 Cherubini
    US Chicago (Burnham)
    Ah ha. OK...... First, Hunter seems to have changed the skeg design from year to year, and I don't know what model year your boat is. Mine is an '82.

    If I were to have tried this with my '82 H30 in the water, I would first need to remove five 3/8 inch diameter lag bolts from inside which mechanically hold the skeg to the hull. The skeg would then be hanging to the underside of the hull; held in place by whatever sealant/adhesive Hunter used 1982, or in my specific case, whatever sealant/adhesive the previous owner used plus the layer of fiberglass they put over the joint in a misguided attempt to strengthen it. I would then need to cut though that fiberglass and the sealant/adhesive underwater to release the skeg. Upon release, the skeg would likely sink to the bottom if not somehow restrained, I would immediately have five open bolt holes in the hull below the waterline to quickly plug before the boat sinks.....and they likely started leaking well before the skeg was free from the hull. :yikes: Personally, I would not do this.

    Instead, if I had a 12 month sailing season like you, I would get in the water a swim mask and/or and underwater camera (selfie stick?), or hire a knowledgeable diver, to assess the condition of the skeg. If replacement is required, I would ask myself if I can get the accurate measurements underwater that would be needed to order a new skeg.
     


    Last edited: Sep 14, 2016
  8. Tony27

    Tony27

    Joined May 2, 2017
    2 posts, 0 likes
    Hunter 27
    US Wisconsin Sturgeon Bay
    I have not seen a post with a picture of what is inside the skeg so I pulled mine off and cut it open. I just bought a 1980 Cherubini that had every thru-hull gooped up with silicone. It had bent shaft and no packing left in it, loose skeg and bad mast step. There is a large block of wet wood in the skeg that the lag bolts are supposed to bite into. It is set in place with some type of mortar like resin covered with a thin layer of fiberglass. I am thinking I will install a large slab of aluminum then drill it and tap threads and use some stainless bolts and toss the lag bolts for a solid long lasting fix.....
    IMG_0066.JPG IMG_0065.JPG
     


  9. Tony27

    Tony27

    Joined May 2, 2017
    2 posts, 0 likes
    Hunter 27
    US Wisconsin Sturgeon Bay
    No wonder it was loose and leaking...
     



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