Round Bilge vs hard chine

Discussion in 'Multihulls' started by nickvonw, Apr 11, 2011.

  1. DaveJ
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    DaveJ Senior Member

    I have to totally agree with CatBuilder, i'm building a F22 and the process is quite fast once you have your processes sorted out. This is a great method for one off builds, but can be used to produce alot of boats. Nathan Stanton from FreeFlow catamarans (and i'm asuming other designers) have built a mold that you can borrow to make your bildges via vacuum fusion and the end result requires no fairing at all. Through these methods, round bildge hulls can be produced with speed and ease with a silky smooth finish.
     
  2. Corley
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    Corley epoxy coated

    Sorry, I must be blind or something, I did not read this for some reason, anyway totally agree and I guess the point is if your moulding foam sheets they bend easily to shape with heat why would you not build a round bilge on your boat?

    You also have to ask the question too as to whether from a whole of life perspective and resale value perspective is a hard chine better? For example Easy's by Peter Snell they still take a lot of work to construct and thier resale is probably half what an equivalent catamaran in foam or duflex composite demands on the market are the savings real? I'm not bagging Peter's designs by the way I feel they fill a niche in the market I'm just questioning the reasoning behind the approach, does this approach really deliver savings in the long term?

    If your going to tip years of your life and large sums of money into a boat (and you will) you have to seriously assess all aspects of the project. A 40' catamaran bluewater cruiser is not going to be a cheap project.
     
  3. DaveJ
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    DaveJ Senior Member

    I would just like to point out that the Schionnings Wilderness series are hard chined, but from what i've seen they still get a good resale value. But i think looks are the biggest factor in the resale of a boat, if it looks great, it will get the better price.

    But when your talking about hard chined to round bildged for resale, the funny thing though is when the boat is in the water, you can't tell if its hard chined or round bildged on looks alone.
     
  4. Corley
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    Corley epoxy coated

    The materials the kits are made of have a bearing on the design it's interesting to note though that later design flat panel kits are moving to round bilge in the form of a hull shoe in combination with flat panel construction above, the Spirited 380, Fusion 40, Pacific 40 and Oceanic catamaran kits have all gone down this path and it seems to be becoming the accepted norm.
     
  5. Richard Woods
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    Richard Woods Woods Designs

    Back in the 1980's when Palamos Boatbuild were building my 35ft Flica and Banshee catamarans two people could layup each hull in a day, just. So say 20 man hours for one hull. (These boats had round bilge hulls and flat topsides.)

    It then took over 2000 hours to complete the boat.

    So building the hulls of a cruising boat is the quick bit.

    There are several ways to speed construction. The first is to make the interior from flat panels, no curves anywhere. Clearly it is much easier/quicker to make bulkheads and interior furniture fit if you don't need to spile curves. Fitting headlinings and even sidelinings is much harder when they are double curved. So flat topsides and decks result in a much faster build.

    Second, no one likes a rough grp interior finish. Instead people like a wood interior. Many people build a foam sandwich shell and then build a wood boat inside it. A lot of wasted time and weight.

    So the fastest way to get a boat in the water is a hardchine plywood design.

    The third way to speed construction is to minimise the electrics/plumbing/engines installations.

    So use outboard engines, manual waterpumps, AA battery powered LED cabin lights etc etc.

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  6. nickvonw
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    nickvonw Junior Member

    hi catbuilder

    whats i was trying to say

    in regards to hard chine vs round bilge was that they can be relatively quick on the water and strong..

    and that they in general are quicker that round bilge to build

    i am sure there are quicker ansd slower methods for both but as a generalisation.

    cheers for the link..v interesting

    n
     
  7. Corley
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    Corley epoxy coated

    I have to ask the question though is building your own boat less expensive? I've built several now two hard chine dinghies and now working on a cold moulded 25' trimaran which is progressing steadily. I've also acquired the plans and building jig for an Ian O Caledonian Yawl which I'll build in due course (probably a double diagonal cold mould I like the method) I certainly have not done it to save money but for the pleasure of working with the materials and the finish of the end result. If your looking to save money and get on the water quickly the secondhand market has a lot of value buying.

    It's very important to be happy with the initial appearance and it's design. If that means hard chines, flat decks and square internal furniture to you then thats fine there is nothing wrong with any of those things.

    I'm pointing out that it's important that your 100% happy with the design and it ticks your boxes, if it does go for it but just make sure your satisfied because it's going to be a large investment in time, effort and money no matter what. For me that means a large boat must have her curves to others it means other things its all a matter of relative value and how much those relative values mean to you.

    What brought the situation home to me was wandering around my local boat hardstand and just seeing the number of abandoned projects, at some stage they have come to a hard patch and decided that it was all too hard so thier initial investment in materials, labour and time has gone to waste. What caused them to get stuck and lose motivation? Lots of people are not well suited to building a boat they have neither the patience nor the ability to appreciate small milestones along the way and derive pleasure from them that is required to keep going.
     
  8. CatBuilder

    CatBuilder Previous Member

    Corley gives excellent advice above.

    Having owned 4 or 5 boats before the one I'm building, I already knew what I wanted. If you don't know what you want, you cannot possibly build a boat. The hours put in for something you are not going to like would be absolutely demoralizing. I can't even imagine how that would feel.

    Good post, Corley.
     
  9. Alan.M
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    Alan.M Junior Member

    Using flat panels and hard chines I had a complete hull shell with 1/2 of the bridgedeck floor in 8 days from starting.

    [​IMG]
     
  10. Corley
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    Corley epoxy coated

    Hi Alan, Thats from a kit? looks like an Oram? It's impressive but would it have taken much longer to set up a hull canoe and attach the flat panels to that? There is certainly a cost advantage to Bob's boats though and a nice finished result.
     
  11. CatBuilder

    CatBuilder Previous Member

    I should have added, "for the same type of boat" to my post. An Oram kit is obviously fast, but not the same boat as in my example. Also, it seems fast to have all that real estate up, but my hulls, coming out in a longer time period, are already completely finished inside with deck already on.
     
  12. oldsailor7
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    oldsailor7 Senior Member

    Back in the day we built two B28 trimarans.
    The B28 is built in the normal manner on a strongback.
    We found it easier to install the flat panel interior while the hull was still on the strongback, before the skin panels were applied. Much easier than having to keep climbing in and out of the hull once it had been turned over. :cool:
     
  13. Richard Woods
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    Richard Woods Woods Designs

    There is a very good reason why production boatbuilders (like Beneteau for example) fit the transoms last

    Also don't fit out the cockpit or saloon until you've finished the hull interior. Use that big flat space as your workshop.

    Otherwise you'll waste hundreds of hours walking up/down ladders

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  14. seaofmirth
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    seaofmirth New Member

    general seaworthiness of single, hard chine (steel) sailboat hull

    Here's a couple of photos of a hard chine (steel) 46 ft. sailboat I am interested in buying. Any observations and comments concerning general seaworthiness of this type of hull are going to be appreciated. Also, can anyone identify the boat's designer's name and the model?

    Cheers,
    Dave Matt
     

    Attached Files:

    Last edited: Feb 6, 2012

  15. Doug Lord
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    Doug Lord Flight Ready

    ==========================
    Dave, try posting in the "Sailboats" forum-this is a multihulls forum-might get more help here: http://www.boatdesign.net/forums/sailboats/
     
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