14' Designed for aluminum

Discussion in 'Metal Boat Building' started by Jack D Davis, Mar 27, 2005.

  1. cyclops
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    cyclops Senior Member

    I really love the flimsey, wood work table. That is a table I can use!
     
  2. Jack D Davis
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    Jack D Davis Junior Member

    Look a little closer, Cyclops. See the channel iron and I beams....bolted to the floor. I just lay 3/4 chip board on top when I want a solid surface. Underneath is a grid of steel. ;)
     
    Last edited: Apr 26, 2005
  3. hoagey
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    hoagey Junior Member

  4. Jack D Davis
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    Jack D Davis Junior Member

    I value my teeth too much (what's left of them). Thanks anyway, Hoagey. I'm rethinking the forward half of the bottom of my model for a slightly softer ride.
     
  5. Jack D Davis
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    Jack D Davis Junior Member

    After a lot of thought about jarred teeth, I've decided to sharpen the bow some to give a smoother ride, at least at lower speeds. The bow is no longer Garvey, but eliptical. Not sure this is how the final will be. I'll probably flatten the deck some, too.

    [​IMG]

    I'm also working on a canoe design for welded aluminum. It will be thinner material and some tell me it can't be done......I hope they're wrong, cause I'm just about ready to put 'er to the test.

    Go to my website to see the canoe plan and the strongback I'm working on. http://www.hmds.ws
     
  6. Jack D Davis
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    Jack D Davis Junior Member

    Being fickle minded, I changed my mind again. Started with a fresh sheet of paper and came up with a new Garvey design. Similar to the original, but much improved (at least in my mind).

    As always, comments appreciated.

    http://www.hmds.ws/garvey_utility.htm

    [​IMG]
     
  7. lewisboats
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    lewisboats Obsessed Member

    I'm a woodbuilder usually, but I work with stainless at work ( meat packing plant). I have wondered...how do you stiffen panels of aluminum. Most of the aluminum boats I see have creases rolled into the metal to provide longitudinal stiff and to prevent flexing of the bottom. How would a home builder go about stiffening the Panels?

    Steve
     
  8. Jack D Davis
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    Jack D Davis Junior Member

    This boat will be built in 1/8" material. Much thicker than the thin sheet metal that is roll formed for stiffness. Should additional stiffening be required or desired, strakes can be added on the bottom or longitudinal stiffeners added inside the hull at the bottom. The sides in this boat will be exceptionally strong due to the tubular foam filled cross section. I may add a few chine to chine frames to accomodate a flat deck which would also stiffen the bottom, but probably not necessary for that reason. I'm still working on details and those may change as the prototype is tested.
     
  9. Deering
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    Location: Juneau, Alaska

    Deering Senior Member

    I have an old Sears Sportfisher with really similar specs to what you're building - same length, beam, etc. Built in FRP (aluminum would be better!), it's a great boat - the ride is reasonable, it gets on step (barely) with a 15 hp with three people, and it has nice initial stability as a work platform.

    One thing you might want to think about is tracking stability - my old Sears has a "keel" shoe about 4" wide and an inch deep running the length of the hull, which I've beefed up with a plate of aluminum for grounding. Without that keel I suspect the handling would be a little squirrely.

    A 15 hp is light for this - a 25 (its rated power) would be much better. The Alaska rule for outboard sizing is "double the rated hp plus 10", but not sure I can endorse that for this boat. I'm thinking about a 40 hp jet since I live on a river. One issue I'll have, and you might too, is whether the boat can handle the weight aft. A 40 hp Yamaha jet weighs 200 lbs. Haven't done a load test yet to see. Also, at least with the Yamaha jets, you'll need a 20" transom.

    What are you estimating the weight will be?
     
  10. skiffboy
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    skiffboy New Member

    Hi Jack,
    I have attached a pic of a 'BarraBuster' that we supply to home builders and professionals in kit form. The kits cover boats of this type from 14' to 18' with the smallest having a maximum engine rating of 90hp.

    The driving concept for the design was to keep it as simple as possible, which means a simple but effective framing system and shell panels that bend into place very easily.

    As soon as you start making things harder, you introduce areas that can go wrong. What I mean is, minimise the amount of bending you need to do to the shell panels, that way you minimise the potential of the boat coming out assymetric. Also, the less welding you need to do the better. It takes a lot of time and skill to keep an alloy structure straight when you introduce heat from a welder.

    I'm sorry if I am telling you things you already know, you seem to be pretty handy from the photos you have posted, I just believe that a simple boat that works will always look better than a complex one that doesn't.

    Cheers,
    Tristan.
     
  11. skiffboy
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    skiffboy New Member

    Sorry, This should have the attachment now.
     

    Attached Files:


  12. Jack D Davis
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    Jack D Davis Junior Member

    Deering: Using the CG formulas to determine the safe HP rating for my Garvey, as shown, It will safely handle a 35HP on the 15" transom. If I go to a 20" transom and remote steering, that changes to 110HP. Transom height will be one of the options offered. I haven't calculated the weight of the finished hull yet. The prototype will be "MY" boat and will be left bare so I can make changes. I suspect it may need a couple of strakes on the bottom. Testing will tell.

    Tristan:
    I trust that you aren't trying to tell me my design won't work. I have designed a simple pipe clamping affair to eliminate tack welds in the seams and make it possible to completely weld the hull from the outside and also eliminate welds on the inside. I posted this method somewhere on this site. Here is a link to it [​IMG]
    This works very well in tests. Again the prototype will tell all.
     
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