Static boat project

Discussion in 'Projects & Proposals' started by Daniel Owusu, Apr 11, 2022.

  1. Daniel Owusu
    Joined: Apr 2022
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    Daniel Owusu Junior Member

    How do folks, very new to the world of boat building pontoon floats ect and working out buoyancy, so I thought this was the best possible step to achieve a successful project by picking the brains of so many.
    I have eight eps polystyrene blocks 8ft x 4ft x 1.5ft and I think I've worked out the total buoyancy of one block but I am doubtful that I've worked things out correctly.

    What I'm trying to achieve is encapsulating the blocks with Lloyds approved polyester resin and glassfiber, constructing a scaffolding tube frame to house the blocks and plonk a shipping container (or two if possible) on top for a static floating home.

    All relevant knowledge and information would be greatly appreciated .
     
  2. Blueknarr
    Joined: Aug 2017
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    Blueknarr Senior Member

    Welcome to the forum

    I hate to be a dream smasher
    But

    All polyester resins dissolves eps.
    So must use epoxy.

    Shipping containers are very heavy for their size.
    They are also a very awkward shape for inhabitation.
     
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  3. jehardiman
    Joined: Aug 2004
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    jehardiman Senior Member

    I agree with Blueknarr here; there are a lot of easier, cheaper, and faster ways to build a shanty boat.
     
  4. bajansailor
    Joined: Oct 2007
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    bajansailor Marine Surveyor

    Welcome to the Forum Daniel.
    I also agree with Blueknarr and JEH - please don't even think about building a floating craft like what you are proposing.
    Even the cost of buying / acquiring the material mentioned in your post above will be significant, along with the cost of building - and then there are the maintenance issues.
    If you want a floating home, there are so many excellent designs out there on the internet - and these are designs that are proven to work.
    The cost of the plans are cheap (never mind that you might think they are expensive) - and you are buying a lot of experience and wisdom with these plans.
    How about doing some googling, and finding some designs that you like, and then posting links to them on this thread to see what BDF members think about them?
    It would be useful also if you could mention where your floating home will be located, if it will be in fresh or salt water, what size it has to be, how many people will be living on board, how much water capacity you require etc.
    The items mentioned above should all be part of your Statement of Requirements - and if you have not yet drawn this up, then this should be the first thing that you do.
    Just don't entertain any thoughts of building with polystyrene, scaffold poles and containers - that sounds like a recipe for disaster!

    Re buoyancy calculations for your foam blocks, if we assume that they are arranged such that the length is 8', the beam is 1.5' and the depth is 4', and that they are immersed no deeper than 2' (giving you 2' of freeboard - which is not a lot really) - then I get an immersed volume of 192 cubic feet. Which corresponds to 11,904 lbs or 5,410 kg in fresh water.
    And just the weight of your container and the scaffold pipe structure will probably already exceed this, leaving you nothing for the comforts of home.
     
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  5. Daniel Owusu
    Joined: Apr 2022
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    Location: Uk

    Daniel Owusu Junior Member

    Once again thank you all very much for responding to my messages.
    My plan was to firstly clad the blocks with 3mm/6mm plywood (construction grade) before the fiberglass. I had worked out that the buoyant capacity was 1.3ton per block (8 in total) and the container weight is 2.2ton empty, I wouldn't have thought the scaffold frame to weigh any more than 1ton?

    This may sound random but if you haven't seen George Clarke's amazing spaces, then season 10 episode 7 a couple take a container and make a wooden frame around it, then pour concrete inside both the frame and container to make a floating home.

    It worked, is that because the space in the container is greater than the concrete hull?
     
  6. bajansailor
    Joined: Oct 2007
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    bajansailor Marine Surveyor

    Yes, this is correct - but only if the complete block is totally submerged. That is why I allowed for 2' of freeboard, and only 50% immersion, assuming that the 4' side is the depth.

    Re George Clarke's Amazing Spaces - here is a link :
    George Clarke's Amazing Spaces: Series 10 Episode 7: A Floating Home and a Magical Vista - All 4 https://www.channel4.com/programmes/george-clarkes-amazing-spaces/on-demand/72498-007
    You have to sign up with them to watch it - I did so, and they asked for all kinds of info about me, and then at the end they told me that I could not watch it because I am overseas (never mind that I had used a UK post code).

    And Season 10, episode 7 does not seem to have reached Youtube yet - they appear to be up to episode 2 :


    The best thing that you can perhaps use those polystyrene blocks for is to use them as positive buoyancy inside a plywood hull built from a proper set of plans.
    Even so, void spaces filled with air provide even more buoyancy than those filled with foam, as the weight of air is less than the weight of the foam. But the difference will be fairly negligible.
     
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  7. Daniel Owusu
    Joined: Apr 2022
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    Location: Uk

    Daniel Owusu Junior Member

  8. Daniel Owusu
    Joined: Apr 2022
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    Location: Uk

    Daniel Owusu Junior Member

    This system for floating pontoon/platforms is the general principle used for making house boats
     
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  9. bajansailor
    Joined: Oct 2007
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    bajansailor Marine Surveyor

    Re your video link above in post #7, yes, that is an accepted method of building marina pontoons with ferrocement - but this is an overkill for what you want.

    There are some neat ideas on the Facebook group about shanty boats - it is private, so you have to apply to join.
    Shanty Boats And Living Lazy On The Water | Facebook https://www.facebook.com/groups/427634977405622/

    Re a simple plywood houseboat, have a look at the 20' and 28' Millie Hill house boats designed by Sam Devlin -
    Millie Hill 20 | Devlin Designing Boat Builders https://devlinboat.com/millie-hill-20/

    Re your video in post #8 above, they mention using plastic drums for buoyancy - have a look at the rolling barge site for some inspiration here -
    Floating Docks | Aluminum Gangways | RollingBarge.com https://rollingbarge.com/
     
  10. Daniel Owusu
    Joined: Apr 2022
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    Daniel Owusu Junior Member

    Absolutely perfect, the last video posted was exactly what I'm going for only with blocks as opposed to barrels.
     
  11. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    An empty 40" shipping container weighs about 8,300 lb or 3,800 Kg.
     
  12. Daniel Owusu
    Joined: Apr 2022
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    Daniel Owusu Junior Member

    So that in theory should leave me with roughly 6.6ton weight capacity. The next problem is, is it top heavy?
     

  13. Crash5291
    Joined: Jun 2012
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    Location: Ontario, Canada

    Crash5291 Junior Member

    6.6 Ton will disappear fast as you start finishing that box out, EVERYTHING weighs something and it adds up faster then you would expect.
    Its not the fridge that will break you its the food in it, its the bed, the sheets on the bed. the bucket for the mop, the mop.

    You will need to take everything into account, including the plumbing and weight of liquid inside. wires, lights wall coverings, and insulation.

    start weighing stuff in your home and list it all out in a spreadsheet i doubt you will like what you find.

    As to Cement floats there used to be a few houses on cement tubs locally that survived fine, although most that build for that now use steel for its strength and longevity. As for freeboard they were built with roughly 18" - 24" intended when finished using full displacement hulls not pontoons.
     
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