From Army idea, 4 mt. Diamond monocoque with Sika adhesived 0.7 mm stainless steel

Discussion in 'Boat Design' started by mustafaumu sarac, Oct 15, 2021.

  1. mustafaumu sarac
    Joined: May 2017
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    mustafaumu sarac Senior Member

    I think this is my final idea to build an outboard engine boat to live in a Aegean coast bay. I saw a diamond shaped boat designed by us army when in times they train rats to go inside russian embassy and plant microphones :)

    I am thinking to build 4 meters long , 1 meter high and 1 meter wide , diamond shaped boat, made with 0.7 mm thick, 1x2 meters stainless steel sheets where there are no welding but sika adhesived stainless steel support profiles.

    Boat will be my night or winter time sleeping bag and greek islands travel companion at colder season.

    I am thinking 0.7 mm thick stainless steel sheets because weight , strenght and price and no need of paint or service are big profits. Strenght will come from steel and the support profiles.

    I am thinking to buy a outboard 9 hp or less.

    kapnD likes this.
  2. bajansailor
    Joined: Oct 2007
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    bajansailor Marine Surveyor

    Umut, please do not even think about building a boat like this.
    For the cost of the stainless steel sheeting and the Sika adhesive (and you will need a lot of adhesive) you could probably buy a nice dinghy all ready to go on the second hand market.
    If you want to build a dinghy, buy a set of plans for a design that is proven to work - and is proven to be reasonably safe.
    I think that your S/S diamond design proposal would be anything but safe.
  3. upchurchmr
    Joined: Feb 2011
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    upchurchmr Senior Member

    What he said.
    Your plan makes me shudder with the terrible boat shape and heavy weight.
    It would make a long lasting coffin.

    Just because you heard the US military did something is usually a reason to run from the idea. They do things for reasons none of us would ever choose on our own.
    And they have so much money they don't care what it cost.
    Spoken as an ex-Navy guy. And a military aircraft structure designer.

    The ARMY designing a boat????? Another reason to run.
  4. fallguy
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    fallguy Senior Member

  5. kerosene
    Joined: Jul 2006
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    kerosene Senior Member

    He will not.

    He has described different kind of concrete boats and other "exotic" structures with nonsensical dimension. He posts there every few years. Either he has issues or is trolling. Probably the former.
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  6. kerosene
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    kerosene Senior Member

  7. kerosene
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    kerosene Senior Member

    or maybe it is humor

  8. gonzo
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    gonzo Senior Member

    The strength of the method is that fools think a faux finish paintjob is a masonry hull.
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  9. fallguy
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    fallguy Senior Member

    No, unlikely. He doesn't have much money, but seems to like boats, so he is constantly working towards the lowest cost solution to sail to Greece. But a sailing canoe is obvious if he could muster up some funds.

    I have decided to be as kind as possible in hopes he is not trolling here, and wishes to really troll!
    Flotation likes this.
  10. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    The caution, for Umut, is everytime I have tried to boat for cheap, I have thrown money away...

    When I set reasonable budgets, I was successful. The budget for the Skoota, long ago blown, was 125k, in case anyone wonders. Canoe budget was $500. Skiff was $8500.

    I bought two boats I thought were cheap, no budget for $3500 that cost $700 to dispose of... I bought one boat for $250 that turned out nice.

    umut's cheapest way to sea is to build a proa I'd say
  11. Heimfried
    Joined: Apr 2015
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    Heimfried Senior Member

    Just a note: a few years ago (Jan. 2018?) Mustafa came along with the very same picture of that boat, which looks like it had a hull out of bricks. I answered his post then.
  12. cracked_ribs
    Joined: Nov 2018
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    cracked_ribs Senior Member

    Unfortunately, boats and in particular boats of one's own construction is just not a cheap thing to get into.

    Any time I see someone on the internet whose post can be summed up as approximately "I want to do this maverick thing because I want to be on the ocean and I know it can be done cheaper than conventionally believed" I just instantly tune out. No, it can't. The ocean is not a place you can safely play without a big pad of cash under you, and that's just the brutal reality. Super wealthy people have mega yachts, wealthy people have yachts, doctors and lawyers have nice boats and regular joes have used boats not much over 20' long. If the price of a used 19 footer makes you flinch, I'm sorry, but boating is not for you.

    For years I ran a boat, often in really rough conditions, that I'd spent $2500 to buy. I put hundreds of hours on it; not really sure how many. Wore out two sets of exhaust manifolds, anyway.

    That's the only form of cheap entry into boating there is: buy cosmetically rough GRP I/O boats from the 80s and know enough about them to keep those old blocks of pig iron running. And I spent thousands upon thousands of dollars in fuel, because my boat was inefficient. But that's about as cheap as it can be done. If that doesn't work for you, get a paddleboard, because everything else is way more expensive.

    That budgetary question is my basic filter when evaluating every interesting idea that comes up. Anyone who's well financed and has a plan in place to make something happen, even something strange like the super narrow high speed freediving boat, has my interest and while I'm not any kind of naval architect, just a guy who designs and builds boats for his own use, still, if I can help I will because that's someone with skin in the game.

    Anyone saying "here's this theory I have and one day I'll build it but I just need to do two more years of research and get some funds together but I'm really close if only I could just get this one question resolved in order to get my wife to agree we should spend the money" I instantly ignore because it's never happening.

    I find Fallguy's 500/8500/125000 comment really interesting because I bet that blowing that budget relates more to the exotic nature of the Skoota than anything else and suddenly it strikes me that the first two numbers are close enough to a bunch of builds I've seen, done, or helped with, that there is probably an equation in which the cost per unit of displacement tracks in a very predictable way and you could graph it such that a pure construction, no fitout monohull with 250lb max displacement would cost something like $2/lb, a fishing skiff with 2500lb max would cost $5/lb, a 10,000lb cruiser $10/'d have to do the math which I never do, I just ballpark everything in my head. But I bet there's a very smooth exponential curve of y=x^a that you could work out pretty quickly if you had a mind to.
    bajansailor likes this.
  13. comfisherman
    Joined: Apr 2009
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    comfisherman Senior Member

    My background is commercial fishing. The industry dropped low for a lot of years, so much so that many of the old builders aged out before the industry recovered enough to need new vessels. I had close familial ties to those old builders and ended up tangentially in building. Professional builders who go over budget by more than 20% should not be in business. I finished a bare hull the year before covid for myself and hit low single digit accuracy on budget. The one finished during covid was just barely over 10% considering the volatility in the market, not bad.

    The reason was being a realist, and being thorough. Amateurs and dreamers suffer from being really poor at both, budgets suffer accordingly. The adage of budget 2x what you think and 5x the time is fair for the dreamer and amateur, bit insulting to the pro.

    Something that cracked ribs brought up and it needs repeating. I'll do it with an example. As a kid my uncle got a 16 foot Lund and a 35 hp 2 stroke Yamaha for a bit under 2k. This was circa 2000ish so a fair deal back then but not an unrealistic one. Lund made them in blue and red and they were affectionately referred to as spam cans all over western alaska.

    They leak, have low sides and pound in a chop. But we used that thing for years and years. It ran 10 miles one way to a neighboring village once a week to buy fresh produce, hauled 10s of thousands of pounds subsitence fish and food. Went on at least a 1000 picnics and days out. The engine ended up needing one topend rebuild in the 10 plus years we owned it. It did all of this with no fanfare or glory, and just a smidgen of a perpetual riveted leak.

    It eventually died one night, it was anchored on a tide flat with other skiffs and an inebriated individual passed out and drove his truck through them. The sides were crushed and the engine swamped and that was the ende of the budget spam can.

    This forum is for enthusiast and daydreamers, it's what makes it fun. Developing a boat that's "just a little bit better" even at great cost is the very core of it. But sometimes it's worth remembering time on the water is easier found from a mass produced unexciting boat nicknamed a spam can....
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  14. bajansailor
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    bajansailor Marine Surveyor

    @comfisherman I do hope that you are writing a book about your adventures - or if you are not doing it now, please do think about it. I think it would be a best seller (certainly amongst folk on here it would be!) :)

  15. clmanges
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    clmanges Senior Member

    Read Scale, by Geoffrey West.
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