Building a floating island/raft from PET plastic bottles like Richart Sowa did.

Discussion in 'Boat Design' started by Boucaneer, Sep 26, 2014.

  1. Boucaneer
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    Boucaneer Junior Member

    Thank you rwatson,

    I didn't realise it could be so light in a modular form size. That certainly interests me, we used to make ferrocement barges here in the fifties in east of England. There are even some pontoons still on the beaches of Normandy from the second world war.

    Right, I will certainly get my head around it and start researching them.
    Yes, mentally I was thinking that they where big, heavy and cumbersome but that needn't be the way and design.

    I can shutter up a hexagon shape to my design and learn how to mix the ferrocement and pour mixing with bouyancy ingredients of maybe polystyrene or another floatation substitute and the reinforced metal skeleton.

    I will look into it, I am building them with a professional plasterer and renderer after all. Maybe this can be a great solution and material to our basic shape and design. In a way, I couldn't see the wood for the tree. I thought it seemed above me but now it seems quite simple. Maybe the cost factor is helping me too.

    Very much appreciated and thank you.
     
  2. AndySGray
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    AndySGray Senior Member

  3. rwatson
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    rwatson Senior Member

    oh - and PS to the concrete

    Pozzolan ( or Fly Ash - a by product of coal burning power stations ) makes concrete waterproof, as the Romans and Ferro boat builders know.

    and

    Glass Fibre - short strands, can be made to add significant strength improvement to concrete too.
     
  4. Boucaneer
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    Boucaneer Junior Member

    Fantastic, thank you.

    I had a read about laminated ferrocement late last night to very early this morning.
    I am certainly liking it. :)

    Still loads more to learn, but this is the way to go.

    Thank you rwatson for the heads up for the fly ash and glass fibre ingredients, that was going to be a question of mine, as it was mentioned in the reading last night.

    Luckily Portland cement and polystyrene sheet and block are available in south asia, so that shouldn't be a problem.

    Like I said, more reading and researching about the process to do as I'm new to it, but this is definatly the way I am going to go.

    So good to find a decent solution, also gives me confidence as it has been mentioned by you guys.

    So mortar and bouyancy of polystyrene flotation weight to study now and to get very familier with the mesh layers to study again now.

    I'm hoping chicken wire can suffice if I can find one with a small opening or even fold it and double it up between the layers of ferrocement concrete laminate layers.

    Maybe I should make the LFC skin slightly thicker than an inch.

    Thank you for pointing me in the right direction, this seems like a fantastic solution and process.

    Cheers. :)
     
  5. Boucaneer
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    Boucaneer Junior Member

    Yes, I am definatly going with the hexagon reinforced ferrocement idea, thank you good folks for the suggestion. That certainly helped me out and save me some unneeded expense.

    I am going to make a few smaller practice models in the U.K before I go to India as a practice. Portland cement can be bought from Wickes or other DIY stores along with the chicken wire.

    So, I'm beginning the project from paper onto practical practice now.

    I shall create a tent space on the miniature island and see how it floats.

    So, just to let you know, it's been a busy fortnight but I'm still going ahead thanks to you chaps.

    I will probably be asking questions about ferrocement ( reinforced ) method here so any advise would be great.

    Thank you again, you guys have helped give me a little more freedom in life, and a fun project to boot.

    Alex.
     
  6. bpw
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    bpw Senior Member

    Try to find one of the old Samson books on Ferro-cement boat building.
     
  7. rwatson
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    rwatson Senior Member

    No we haven't. We have condemned you to several years of frustration and great expense.
     
  8. Boucaneer
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    Boucaneer Junior Member

    That's alright RWatson mate, I'm used to living in East London, you can't get more frustrating and expensive than that. ;-) Well on the frustration part anyway.

    Thanks for the book recommendation PBW, I shall take a look, thanks.
     
  9. Gump
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    Gump Junior Member

    I'm probably late to the party here, but I could show you a few ideas I've used to make "junk" flotation practical. (if your concrete flotation sinks...)

    [​IMG]

    [​IMG]
     
  10. Gump
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    Gump Junior Member

    Here is another idea that is more in line with what you are trying to do:

    [​IMG]
     
  11. rwatson
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    rwatson Senior Member

    Its obviously never been tried. Whats this "Post size large enough to trap flotation material within tyre void" and "water trapped within void creates ballast",

    My bet is that these things would float horizontally.

    And what holds the tyres together ?
     
  12. Gump
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    Gump Junior Member

    Center post should be about 1" smaller diameter than the hole in the tires...

    1/2" gap would allow water to flow but keep flotation trapped within...

    Tires would naturally be held on posts by their own buoyancy, but a larger plate could certainly be bolted over the bottom tire....

    would be very stable because of the weight of water momentarily trapped within the tire column.

    depth of pilings could be adjusted to weight of decking.
     
  13. rwatson
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    rwatson Senior Member

    whats the post made of ? I bet it would still float horizontally even if it were steel, and if they were made of steel thick enough to withstand a marine environment, the things wouldn't float.

    Lets talk about how you fasten the deck to the posts, and how much weight of decking would it support

    Like I said - its just a picture, and it doesn't come with any figures and calculations, and I bet it isn't even economical compared to commercial solutions.
     
  14. Gump
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    Gump Junior Member

    Large diameter posts would not need to be structural. A 15" diameter plastic culvert pipe would function to hold the ballast within the tires. An internal post could be a simple "marine grade" post... perhaps 6" in diameter with flanges welded on both ends to bolt to the decking ?

    Of course there are no calculations..... but I'm certain it would work... and would be impossible to turn horizontal.. posts could be spaced around the decking at whatever spacing would be needed to achieve a stable platform.

    Perhaps I drew it too extremely. I was thinking in terms of an "island" as the OP discussed. Imagine the tire stack to be only 4 tires high.... with perhaps more stacks around the deck perimeter..... with a small 2" threaded pipe with flanges for internal structure.... That would be significantly cheaper than commercial solutions. Given the idea that the tires and flotation would be free.
     

  15. Gump
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    Gump Junior Member

    The idea could also be modified like this :
    [​IMG]
     
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