Brine Shrimp Catamaran

Discussion in 'Multihulls' started by kelldog, Aug 8, 2017.

  1. upchurchmr
    Joined: Feb 2011
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    upchurchmr Senior Member

    You might look for a rig off of a Hobie 16. Or another daysail cat.
    I bought a complete boat for $300 - the hulls were completely shot.

    What cruisers forum? You guys are holding out on me!
     
  2. kelldog
    Joined: Jun 2009
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    Location: Bakersfield, CA

    kelldog Junior Member

    I do have a Hobie mast that came with the boat. The previous owner was going to set it up but never got around to it. I'll probably use that to start.
     
  3. hump101
    Joined: Oct 2004
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    Location: Brittany, France

    hump101 Senior Member

  4. kelldog
    Joined: Jun 2009
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    Location: Bakersfield, CA

    kelldog Junior Member

  5. ThomD
    Joined: Mar 2009
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    Location: TO

    ThomD Senior Member

    "Question 1; I would like to lengthen the hulls by 3 feet to 27.4 feet. Where would be the place to insert the 3 feet? The section just before the aft beam? The section forward of the forward beam? Or, right in the middle of the hull/cabin."

    The only reason I heard was to increase payload. If you stretch the whole thing out by 3 feet you will only gain 159 pounds on a design payload of 1300, minus whatever you add in weight, new rig weight, and so forth. Sounds like a bad idea for loosing a year in the water, best case, it is a big job, though I guess you have a long build season?

    You could easily get the same displacement with a shoe keel, or with overmolding corecell.

    The only way I would do it is on the front and end of the boat. You would have to fair a fair amount in, but there are fast ways to do that. If you add in the middle every single bulkhead, etc... will be out of place, when you make those cuts the boat will spring apart, the result would be some very tiny improvement in the displacement strategy over doing both ends. You can do only the front particularly if you want a certain addition for wave piercing. The back is normally done when the transom drags in the original, or someone wants boarding steps, or to convert a transom hung rudder. So you need to see the boat sailing, and overloaded, to guess what would be the best strategy. But adding 1.5 feet to the front and back, or say 1 to the back and 2 to the front, could depend on how she carries her current weight.

    One thing you can do with a ply boat is consider weight saving upgrades. It isn't true that cored structures are lighter than ply. I have done some numbers where the opposite turned out to be true. But then again it can often be true. Replacing decks or cabin tops, generally upgrading, can give you significant weight savings, that all pay back into the displacement purse, and clean up the look. And rather than making a boat less saleable because you have a home build that is now a home design, you show respect to your main asset, the designer's name by simply upgrading. I know of one Buch, that was so upgraded that it is now all corecell composite. It wins a lot of races. And along the way, if you have some problem areas with rot or whatever (sometimes never happens), your repairs will just take care of your upgrade path.

    The rig can also get you more weight savings for your 159 pound target. Get a rotating rig, like an old hobbie, or make a carbon version, as the Gougeons did, it saves weight and sails stronger without increasing your sail area and compromising the position of the CE. Get composite rigging, it is cheap on a boat that size. Etc...

    If the implement radical weight loss, or sail area increases on the same boat, you will affect the margin of safety, which has to be given some thought, but if you are looking to optimize load carry it shouldn't mater.
     
  6. ThomD
    Joined: Mar 2009
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    ThomD Senior Member

    Overlooked tool is a sharp paint scraper.
     
  7. markstrimaran
    Joined: Dec 2014
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    Location: usa

    markstrimaran Senior Member

    Just watching, I added an aka to my catamaran.
     
  8. kelldog
    Joined: Jun 2009
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    Location: Bakersfield, CA

    kelldog Junior Member

    20171028_144432.jpg

    Here is the dagger board slot that I needed to repair. I have sanded, epoxied and fiberglassed up into the slot. It was verrrry difficult to say the least! I sealed up the opening and waited a week; then poured salt water in from the top. It appears that I have sealed the leak. No water coming into the cabin where the daggerboard case is attached but I will now pour thinned epoxy in the area inside just to seal it more.
     
  9. upchurchmr
    Joined: Feb 2011
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    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    There is nothing valuable about thinned epoxy.
    Just use full strength and get the designed sealing and strength.
     

  10. rattus
    Joined: Feb 2008
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    Location: US

    rattus Señor Member

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