Modern boat made simple, ferrocement flat sides and bottom and top

Discussion in 'Boat Design' started by mustafaumu sarac, Jun 6, 2018.

  1. fallguy
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    fallguy Senior Member

    Right. I misspoke when I said expensive...
     
  2. David J Ritchie
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    David J Ritchie Junior Member

    Concrete boats are an old idea carried out already with some success!

    These have got to be less expensive on material cost right?







    Maybe these can give the OP names to google for more detailed information and some inspiration.

    Good luck OP and be careful!
     
  3. CT249
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    CT249 Senior Member

    Why?
     
  4. fallguy
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    fallguy Senior Member

    Completely unsubstantiated.

    But for a moment, let's assume it true.

    Would you prefer a hull that floated or sank when it took on any water?

    If you build a boat; is cost the primary goal? The OP does not even talk about the type of craft. His direction is unwise. Kindness does nor always mean approval.
     
  5. dsigned
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    dsigned O.R.C. Hunter

    You just posted a 45 year old study. Anything done in the past couple decades?
     
  6. dsigned
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    dsigned O.R.C. Hunter

    As far as I know there isn't anyone working with concrete boats outside of an academic setting. There's some interest in Germany (the universities tend to make "fun" boats to go along with the canoes), but I think for a decent concrete boat you'd be better off finding a civil engineer who'd done a concrete canoe. There's a ton of really cool stuff you can use to make concrete do all kinds of things it's not known for, but nothing currently in the boating community, which seems to have a hard on for million dollar carbon foiling boats and nothing else.
     
  7. motorbike
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    motorbike Senior Member

    I think the answer youre looking for is pycrete, you just need a small electric fridge run off solar to keep it cool. Concrete as a boatbuilding material has no advantage over more conventional timber or steel including price when all the other equipment, gear and labour is added up. Plus its heavy, really heavy for a small boat. Maybe there is an outlier who has a high tech lightweight concrete boat but guarantee it will have cost more than most other forms of construction. Best use for concrete is marina pontoons.

    If you head to the local built fishing and sailing fleet, there you will find the cheapest and best materials in use.
     
  8. dsigned
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    dsigned O.R.C. Hunter

    Lots of unsupported statements there. Do you actually have any experience with modern high performance concrete mix design and curing, it are you yet another armchair "expert" whose most recent experience with concrete is the 1970s?

    As someone whose read a lot of academic research from the last 25 years or so (i.e. early 90's) concrete design and testing, and implementation, I can tell you that almost nothing that you wrote above is true. You're just furthering misconceptions that, though oft repeated, are no less false and perhaps worse for a forum that purports to be focused on "design", are not backed by even the facile attempt at supporting evidence.
     
  9. dsigned
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    dsigned O.R.C. Hunter

    Concrete does not necessarily sink, it depends almost completely on what kind of aggregate/filler is used. Perhaps more damning to your argument is the fact that steel, aluminum and fiberglass are all heavier than water. The things keeping them afloat in an impact scenario are floatation compartments, which could be implemented just as easily in concrete as in steel, aluminum or fiberglass. Moreover, concrete is more resistant to corrosion than steel, wood or aluminum, and has the added benefit of resisting UV exposure as well.
     
  10. fallguy
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    fallguy Senior Member

  11. fallguy
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    fallguy Senior Member

    I think you need to realize the OP only wanted a cheap boat. He didn't say sail or row or fishing or anything but cheap. For a guy who has the nickname dsigned; that ought to raise an eyebrow or two. If he was going to build with steel and concrete; it wouldn't be cheap and it wouldn't likely float if it were!
     
  12. dsigned
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    dsigned O.R.C. Hunter

    For a guy who's so comfortable being condescending, you sure are comfortable making unsupported statements!

    Do you have a link to an academic resource comparing construction costs for concrete vs. plywood vs. fiberglass for boats of given lengths made in the past 20 years? I'd love to read it if so, as I've looked pretty hard for just such a study, and beyond some very small studies done on very small boats, there's not much out there.

    Why don't you make a comparitive cost estimate of a boat made from concrete, vs. whatever material you think is cheapest? Maybe give us some estimates on upkeep in a marine environment while you're at it.

    Unfortunately that would require thinking and effort on your part, areas you don't seem particularly keen on embracing when it comes to this topic. That's fine. Go do those things for a topic you think is worthwhile. Just stop cluttering the thread on this topic with your inane conjecture.
     
  13. fallguy
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    fallguy Senior Member

    Inane conjecture?

    What is the sor of the ops boat?

    If you weren't here for the polemics, rather than responding to me; you'd respond to the OP, who made a claim that he could use 100$ in materials to build a concrete boat.

    I was actually rather decent to you and him.
     
  14. Mr Efficiency
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    Mr Efficiency Senior Member

    It sounds like the ultimate shoestring budget project, to be depending on little more than loose change, to get into boating.
     

  15. rwatson
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    rwatson Senior Member

    The BIG problems is, that ANY hull is about 1/3 the cost of the build. A saving of 50% in a hull is about $13,000 in an $80,000 boat.

    Then just look at the re-sale value of concrete boats. You would lose as much as you saved directly after launching.

    Then there is the tendency to cost a concrete hull as the materials only. As someone who has spent dozens of hours, and watched builders spend 2 months, tying off all the little tie-points after months of steel layiing and faring, and then trying to find a good team of plasterer to layup the hull in one day, that doesn't impress me at all.
     
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