junk rig catamaran made from plastic bottles?

Discussion in 'Multihulls' started by RussellEngland, Apr 23, 2011.

  1. HakimKlunker
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    HakimKlunker Andreas der Juengere

    I believe that your idea will float in some way.
    What do you have in mind?
    I believe it to be allright as a toy or experimental object. However: if it is meant to travel far, I would have concerns about structural strength and seaworthyness. Durability also is a topic to think about.
    If you have the idea to save the environment, think about how long your vessel will last; otherwise you only delay the occurance of waste material and perhaps the 'place of delivery" depending on where it falls apart.
    Not even talking about all the petrol burnt on vessels coming to save your life if (most likely) something goes wrong.
    Plastic bottles in my eyes have more value in being recycled and to have a second life - maybe again as a bottle.
     
  2. MAINSTAY
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    MAINSTAY Junior Member

    We can and should design several soda-bottle boats

    HakimKlunker

    Strength, seaworthiness, and durability are vital if this project is to succeed in anyting more than a daysailer. And means and methods and materials to assure those things are exactly what is needed in this forum. It needs the experience and expertise of members like Petros and Mungus, and others not yet heard from, to achieve that strength, seaworthiness, and durability.

    I've never built anything with 2-liter bottles, except a fuller recycle bin.
    I do have experience in materials and in sailing, and think that together we can design a better boat than any one of us could.

    And maybe Russ and some of our viewers will each build one and have fun with it. Or mungus will win a trophy. Or how can a return to civilization be achieved by that hypothetical guy stranded by that bay that catches all the junk floating on the ocean, you know the one; and by that junk yard with wrecks that contain every part in the right material, gauge, thread and quantity he will need; and near that abandoned boat yard with all the hand and machine tools he'll need; and by that high-rise construction site; and of course, with parachute delivery (otherwise he wouldn't be stranded) by DHL of everything else; and has internet access as well (how else to get our sage advise or order delivery?). Or some refugee without those resource will get his/her family to safety.

    2-liter bottles are everywhere. At the very least, our forum may get people to gather the scattered remnants of parties ashore and afloat into piles that are glued, tied, taped and/or wrapped together for easier delivery to the recycle center.

    LMo
     
  3. whitepointer23

    whitepointer23 Previous Member

    i have an idea that may be worth consideration. in my water proofing business we use a latex based polyurethane liquid membrane and geo cloth which gives exceptional strength to anything it is applied to and is uv stabilised. the boat hulls could be constructed from bottles with sika and sheathed with the membrane which will give a smoother surface which can be painted as well. its got me thinking about knocking up a small tender to test the idea.
     
  4. brian eiland
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    brian eiland Senior Member

  5. HakimKlunker
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    HakimKlunker Andreas der Juengere

    I wasn't trying to block the stream of ideas.
    'Bottles-to-bottles' was rather a provocation, I admit, and I am not sooooo traditional after all. The guy on the island has been my neighbour actually ;)

    Thematically I see at least two major topics in this concept:
    1. is Technology
    2. is Ideology

    Plastic bottles have lots of (in boats) unwanted features.
    My question here is if at least the most important issues can be solved.
    My approach is to doubt and question each and every little detail. If it then turns out that there is a solution, it means that it can be done.

    Big trouble in my imagination is to give the vessel a shape that makes a hydrodynamic sense, so that on the water there is a certain control of direction and also (relative) safety.
    As a bottle has its given shape I expect a somewhat uneven hull.
    There are not only 2-ltrs bottles and so with different sizes and shapes there will be an improvement of options. Smaller bottles can i.e. assist to taper the hull/s towards the bow/s.
    The idea to 'wrap' the construction is interesting; it will help to reduce jumps between bottles. I do not expect it to be 100% waterproof and I wonder what the trapped water and marine life will be doing?

    At first sight it looks to me as if the floats will have to be entirely bottles with no volume available for storage or accomodation. That will require all 'living space' on the platform - or call it deck.
    To build up a somewhat traditional skin from bottles only outside would require a framework and still will be kind of unstable.
    I would say that if too much 'new' material is used, the concept of recycling bottles will be distorted. That is what I had in mind with 'Idealogy'.
    As it was mentioned by Mungus, Sika indeed looks like one of the materials that will do a good job. Also Whitepointer's membrane sounds attractive.
    At a certain point however, there may be so much regular and new material added, that the project ends up like a normally built boat, where some unusual material is added.
    At that stage, I reckon that the original idea is lost.

    Next point to investigate seems to me: how can it be made strong enough?
    Just now I tend to say: the bottles are too weak. Let them do the flotation only, and create a sort of framework that takes the loads. Especially those from the rigging.
    One approach may be taken from another thread. The boat appears to have similar structural requirements:
    http://smalltrimarans.com/blog/?p=5052
    http://ckdboats.blogspot.com/2011/01/energy-diet-in-hout-bay.html
    (Maybe we find a translator for the latter link...)

    Coming to the aerlier suggestion for i.e. sail materials: Some of the regular (waste?) plastics will not last, being bio-degradable or else. The same will count for some other appointed 'materials'. For the sake of safety I think it prudent to test those articles beforehand.
    That makes it logic to add point 3. to the list above, wiz 'material research'.

    Depending on what is found and/or available, I expect to meet some weaknesses; that perhaps will pose some restrictions of where and how the vessel later can be used. At last there is always the question about personal safety.
     
  6. ProtectTheOcean
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    ProtectTheOcean Junior Member

    Russell, I'm glad to see that you got more cooperative and serious responses on this thread than the naysaying bitches' replies from a similar thread I started recently. Keep at it. Use the bottles for very cheap sealed buoyancy. I'm told by one of the crew of Junk that the tops started unscrewing themselves just a couple days out, so they ended up cementing those caps shut. The fellow with the suggestion of filing them may be on to something, as they WILL otherwise expand and contract.

    My own concept included sheeting/skinning the amas so that the bottles themselves could provide STRUCTURE. One shouldn't need to put in any significant skeleton if the bottles are filling in the void.

    I've seen kayaks made by cutting the bottles and resealing them directionally, one stuffed into the next. Not sure I'd trust that seal for a boat, even a coastal cruiser, but it does demonstrate the need to be conscious about hydrodynamics.

    Good luck with your project. Not sure I'll be sticking around here much longer. Got too much to accomplish to be wasting energy on negative folk... but I'm very glad you got more constructive suggestions here, and that you're taking the project on. Keep at it!
     
  7. CatBuilder

    CatBuilder Previous Member

    Wasting energy is exactly what you are doing if you don't stop dreaming for a second and crack open a book.

    Look up the materials properties of the various materials you wish to use, then compare to real boat building materials.

    That'll save you 1000's of hours and $1000's of dollars.

    And don't forget every dollar in your pocket to spend on this was earned through trashing the environment. The whole planet is connected, even the monetary system, as capital goods are expended to earn dollars. So, wasting dollars on this type of thing (if it's not a 100% success) is also bad for the environment.
     
  8. HakimKlunker
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    HakimKlunker Andreas der Juengere

    Hmm: the opening of this thread is entirely technical. To my understanding here we are not talking of how to make the world better, but rather: It is there already - what can we do with it.
    Russell: Maybe you can clarify the motivation of your post?

    PtheO: If we talk about waste - nobody really needs a pleasure boat; and that is what we discuss here, no?
    Your issue is a good idea, but it is not only off topic, but also off forum :)
     
  9. HakimKlunker
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    HakimKlunker Andreas der Juengere

    just came into my mind: If it turns out to be unsafe to make a boat from it, it still may be good for a mooring pontoon?
    A bottle is lastly not created to be a boat. Good engineering includes correct choice of materials (But unsuitability of pl./bottles is not proven yet)
    Not sure: Russell, is it ok for you to include a 'green' discussion here?
     
  10. MAINSTAY
    Joined: Feb 2005
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    MAINSTAY Junior Member

    A success

    Whitepointer23
    Your sugestion about geocloth reinforced polyurethane membrane is good. It has the flexibility I suspect is needed.
    ______________________


    Brian
    Glad for your input, buddy. I didn't know 2-liter bottles were heat-shrinkable. That has possibilities for tapering the bow more hydrodynamically than the steps I had proposed.
    ______________________


    HakimKlunker
    Question away, please.

    Our design was exploring the answer to: How can a catamaran hull be made using bottles? I like your suggestion of using different size bottles in the prow taper. I seem to have fixated on 2-liter.

    The questions where 'hull' is replaced by bridge, accomodations, standing rigging, steering, running rigging; and analysis for stability and strength have yet to be faced. And I expect those answers will require modification of the hull answer.

    My idealogy is similar: to use discarded, recycleble material to a reasonable maximum. 'Reasonable' has elements of effort, energy, and safety.
    ______________________


    CatBuilder
    You miss the point. This is not a business or an investment. We are not building a 'real' boat. We are building a boat using discarded, empty 2-liter plastic bottles to a maximum. It may not look like a 'real' boat when we're done. It may violate every rule of thumb and ratio that is applied to a 'real' boat. But, I'll consider it a 100% success, if it floats and reaches.

    I'd accept a broad reach. And that no one gets hurt. Three things: float, reach, safe, and a fanatical divotion to.... FOUR things: float, reach, safe, no epoxy, and a fanatical divotion to.... FIVE... (with apology to SNL)

    I'd call it a success if we found that plastic bottle are unsafe to use for boats. It's a success because we found another way to not build a boat.

    LMo
     
  11. brian eiland
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    brian eiland Senior Member

  12. brian eiland
    Joined: Jun 2002
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    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

  13. brian eiland
    Joined: Jun 2002
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    brian eiland Senior Member

    Floating Dining Structure via plastic bottles

    Here is an interesting idea for third world floation

    This temporary floating dining room was designed for a summer fundraiser by The School of Fish Foundation, a non-profit organization committed to promoting sustainable seafood. The semi-enclosed space floats on over 1700 recycled plastic bottles. The project intends to bring attention to the abundance of plastic litter floating in the oceans, but also suggests a possible use for such waste.

    go here for photos and website link:
    http://www.boatdesign.net/forums/boat-design/need-advice-building-houseboat-lagos-nigeria-35580-2.html
     
  14. HakimKlunker
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    HakimKlunker Andreas der Juengere

    All thermo-plastics can be re-formed with heat. I would suggest to test this feature. I would be worried if with the heat there will be a relevant change in mechanical properties, although theory should so 'no'.
    Some of the bottles' strength comes from their shape I guess. If the shape is changed, the individual strength will change?

    Until now no one suggested to cut open the bottles and produce 'hull plates'.
    These mini-sheets can be glued together and will make a quite nice skin.
    However: This involves a lot of work and a lot of glue.
    Certainly not an economic concept, but at least one other way.
     

  15. HakimKlunker
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    HakimKlunker Andreas der Juengere

    I would like to study THIS stuff a little more. Is there a link?
     
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