Considering Homebuilding a ~50' Catamaran

Discussion in 'Multihulls' started by Iridian, Jun 10, 2021.

  1. fallguy
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    fallguy Senior Member

    So awesome. I am in year four of a 32' build and my work socks are all glass impregnated. I told my wife when I am finished, we are having a sock burning party and I am gettin all new ones.
     
  2. fallguy
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    fallguy Senior Member

    for 50' boat, you need labor, some skilled, not from the USA unless you have a til runnin 24/7
     
  3. comfisherman
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    comfisherman Senior Member

    I don't disagree with your observations on aluminum. I've owned steel aluminum and fiberglass, now have built in all three as well. Fiberglass definitely has the more desirable ene product but in a one off situation it's best to know upfront its limitations. I'm building off a known hull with a different deck, cab and gear arraignment. I'll triple the time of this same boat in production trim. Its setup for a 6 foot ceiling height and I've not been that short since middle school....

    Alloy is faster but galvanic corrosion is a real issue even when planned for and well maintained and the insulation factor cannot be overstated. I'm a cold weather fisherman and the swap between glass and alloy is fairly profound. But it I'd hard to shake the reality of the speed. A good alloy boat is good for 20+ years before the white powder of corrosion rears its ugly head. The insulation properties are mitigatable but I've not seen a true cure so fair point there.

    For me being young the investment upfront was worth it. Were I over 50.... it would be alloy with some good coatings and someone else's problem about the time I'm on the wrong side of the grass....
     
  4. power boater
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    power boater Junior Member

  5. guzzis3
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    guzzis3 Senior Member

    Couple of quick points.

    Have you emailed Richard Woods ? He is extremely knowledgeable both cruising and building.

    Building hull skins is a small part of the total build. This can't be stated firmly and often enough. Save 5 minutes taping flat panels together, spend years fitting out. There are plenty of well advanced techniques for building fast molds for rounded sections, and building a big flat panel table and infusing panels is quick straightforward and will save you a fortune over factory made panels.

    Here are some quick sample prices from UTEK in china. They include port and taxes for australia.

    Fiberglass foam and epoxy https://sangowizzercatamaran.blogspot.com/2019/01/fiberglass-foam-and-epoxy.html

    Foam is the dear bit. 12mm foam is about US$15.5 meter squared including shipping but not port charges.

    From your previous comments I assume you are talking about sailing speed. It's great fun to give a boat it's head for an hour but if you think you are going to cruise flat out you are probably wrong. You won't be able to take the pounding and stress of over 10 knots in a seaway day in and day out. Ellen Macarthur can do stuff like that, us mere mortals really can't.

    Your carrying capacity is below the waterline. Everything above the waterline costs payload, so the more structure your boat has the fewer ducked air conditioners, walk in coolrooms and spas you can carry. A bridgedeck cabin costs money and payload. At those sizes there will be no lack of spaces in the hulls for the billiard table and the squash court.

    Foam boats are less reliant on furniture than ply metal etc. It's easy to build a lot of the required stiffness into the skin. This allows rearranging the interior to suit. 2.5m bunks should be easy to accommodate. I very much suspect the reason why so many of these boats top out at 6' is that is the headroom most people expect. I am quite sure lifting the cabin roof will not be a big ask for any designer. It's above the beams so it doesn't have the big structural implications as lower down.

    You might also contact Ed Horstman who has an extensive range of tris and cats. See if any of his boats have higher headroom:

    Ed Horstman Designs https://edhorstmanmultihulldesigns.com/index.php

    I believe the suggestion of building a smaller boat by a couple of people above was as a practise build so you can see what problems arise building for your height. Make mistakes on say a 20' or 15' boat then be better prepared when you start your big cat...
     
  6. Scuff
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    Scuff Senior Member

    The horstman trimarans have over 6' clearance on the designs over 27'. I'm building the 27-9 and it has 6'3".
     
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  7. guzzis3
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    guzzis3 Senior Member

    He's 6'8" so he probably wants 7'. Given he wants to go big EH's bigger designs might get you there.

    I'm still not clear on what the OP hopes to accomplish with really long hulls.
     
  8. Iridian
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    Iridian Junior Member

    @comfisherman I'm 25 now, so optimally this boat will last until I'm too old to sail it.

    @powerboater Thanks for the video. Its too bad there isn't a longer series on the boat. That's an absolutely impressive amount of work, the finish and joinery is much beyond what I intend, I'm looking for a much more minimalist interior. It looks like it'll be a wonderful cruising boat though when it's done.

    @guzzis3 I haven't emailed Richard Wood yet, as I'd like to get my workshop situation settled and a bit of experience under my belt before wasting the time of boat designers. Hoping to fully have my list of requirements down and a shop ready in a little over two years; would engage with them at that point. Thanks for the info on the foam core. Will definitely have to shop around a lot to figure out the best way to get the prices down on the foam/resin, I'm on the East Coast of USA, so I'm not sure how much that changes the prices. I hadn't seen Ed Horstman's designs. I'll shoot him an email and find see what the height is throughout the saloon/hull.

    I hear the "hull construction" is the quick part again and again, and I believe it 100%, though I'm curious as to where the rest of the time comes in? Is it mostly in the painting and fairing, along with the interior joinery? I've heard estimates as much as 20% of the build time solely on sourcing parts for the fit out.

    With regard to speed, I don't think I'll be cruising 24/7. The pounding on my H20 is bad enough, I imagine it'd be even worse on the open sea in rough conditions. That being said, I want to continue to travel, I grew up overseas and want to continue that on my boat, rather than just going back and forth in the Caribbean. A quicker boat gives you a lot more options in dodging weather patterns, something I think is pretty important when you are more stable upside down than upside right! Might be fun to do some of the races as well, such as the ARC.

    With regard to the long hulls, I've got a couple of thoughts on the issue.

    1. I'll be stuck working for at least the next 20 years anyway, so additional build time isn't as big of a concern as being happy with this thing, so long as I can maintain motivation. When I retire, I want to live aboard full time, and go around the world. (I recognize that this may just be a pipe dream, but if I'm going to start the project, I may as well do it right)
    2. Freeboard as a fraction of hull length is going to have larger negative effect on the performance and stability of a smaller boat. I'm looking at 12'+ feet of freeboard. (3' bridge deck + 7' interior space + 2'? of saloon roof and floor. On a 36' boat, that's fully 1/3 of the total length in height and about 2/3 of the beam. In comparison, on a 52' boat, that same 12'+ feet of freeboard is only about ~1/5th of the length and 9/20th the width. The hull height and saloon height is essentially the same from a 36' cat to a 68' cat.
     
    Last edited: Jun 17, 2021
  9. Rumars
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    Rumars Senior Member

  10. comfisherman
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    comfisherman Senior Member

    Hull is the easy part for sure. Deck, bulkheads, and all the other structural components are the long part. With that said it's all part of the ride.

    As to length. Its definitely easier to compensate for height on a longer hull. My grandfathers 52 footer hid the 6 foot 7 ceiling heigh with a lot better aesthetic than my 32 footer.


    If the budget allows, nobody has ever preferred a 36 over a 50 foot boat. 48-55 is kinda the perfect size for a single family to sail. I'll agree there is such a thing as too much but boat but it's not a 50 footer, unless your a staunch minimalist with no family or prospects.
     
  11. gonzo
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    gonzo Senior Member

    That's not so. I often sail solo and would rather cruise the smaller boat.
     
  12. TANSL
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    TANSL Senior Member

    Naturally and a child prefers an optimist.
     
  13. comfisherman
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    comfisherman Senior Member

    I'll let my last sentence stand.
     
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  14. fallguy
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    fallguy Senior Member

    I can keep a small enough boat slipped at my own place. So, I am pleased with the size decision.
     

  15. gonzo
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    gonzo Senior Member

    There are many preferences. To each his own.
     
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