Raft building help!

Discussion in 'Boat Design' started by junkrafter, Jun 8, 2009.

  1. junkrafter
    Joined: Jun 2009
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Indiana

    junkrafter New Member

    I'm building a junk raft, which three people will paddle, for a trip down the White river in Indiana. I've been collecting materials which include: garden mesh fencing, bottles, and plywood. From what I've read this seems to be a good start for a junk raft, but I'm also curious to alternative flotation methods as well as other materials I might use to build the raft. I'm only looking for items which I might get for free, so this has become quite a challenge.

    If I were to inflate an everyday pool raft, and cover it with duct tape, would this be sturdy enough for raft flotation? That is, if I got many of them would this help?

    I'm not set on any particular form of flotation, and will probably have to use many different forms. Keep in mind, this raft will need to hold 3 people.
     
  2. junkrafter
    Joined: Jun 2009
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Indiana

    junkrafter New Member

    The trip will be, at most, 200 miles.
     
  3. rasorinc
    Joined: Nov 2007
    Posts: 1,854
    Likes: 71, Points: 48, Legacy Rep: 896
    Location: OREGON

    rasorinc Senior Member

    Empty 1/2 gallon milk bottles. Glue the tops on with waterproof glue. Each bottle will support about 40 pounds.
     
  4. junkrafter
    Joined: Jun 2009
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Indiana

    junkrafter New Member

    I've actually been collecting every kind of plastic bottle: water bottles, 1/2 and full gallon milk jugs, laundry detergent bottles, 2-liters...you name it.

    I didn't think to glue the tops shut the though - that's probably important. :D

    I didn't realize a single 1/2 gallon milk jug could support 40 pounds. Is that a typo?
     
  5. junkrafter
    Joined: Jun 2009
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Indiana

    junkrafter New Member

  6. rasorinc
    Joined: Nov 2007
    Posts: 1,854
    Likes: 71, Points: 48, Legacy Rep: 896
    Location: OREGON

    rasorinc Senior Member

    A cubic foot of air floats 62 pounds in fresh water. I estimated a 1/2 gallon jug to be 2/3rds of a cubic foot.
    1 dry gallon = 0.15 cubic foot 1/2 dry gallon =0.077 cubic foot. So I was far off.
     
  7. amolitor
    Joined: Jan 2005
    Posts: 87
    Likes: 3, Points: 0, Legacy Rep: 17
    Location: San Francisco

    amolitor Junior Member

    1 gallon of water weighs 8 pounds. Half a gallon of water weighs, therefore, 4 pounds.

    Guess how much volume a half gallon bottle displaces?
     
  8. rasorinc
    Joined: Nov 2007
    Posts: 1,854
    Likes: 71, Points: 48, Legacy Rep: 896
    Location: OREGON

    rasorinc Senior Member

    0.077 of a cubic foot
     
  9. rwatson
    Joined: Aug 2007
    Posts: 5,852
    Likes: 290, Points: 83, Legacy Rep: 1749
    Location: Tasmania,Australia

    rwatson Senior Member

    God, you imperial people have it tough. :)

    1 litre of water - 1 kilo, makes displacement theory soooo much easier.

    Do you guys see a lot of polystyrene crates used for vegetables packing over there ?

    They would be a good item ti use.
     
  10. messabout
    Joined: Jan 2006
    Posts: 3,045
    Likes: 231, Points: 63, Legacy Rep: 1279
    Location: Lakeland Fl USA

    messabout Senior Member

    Rwatson: Egad ! You are so right about our outlandish imperial system. We are enduring an evil curse to be sure. A half gallon jug will displace about 1.666 kg. of fresh water I reckon. Do the Brits continue to insist that they be weighed in "stone" ?? I am pleased to note that we do consume our US booze from metrically marked containers. But not beer. That is marked in ounces... I wonder if the Brit pint of Guiness is the same volume as our 16 ounce size. :confused: I envy you Aussies who are so damned independant that you adopted a non ancestral system of measurement in favor of a sensible one.
     
  11. peter radclyffe
    Joined: Mar 2009
    Posts: 1,406
    Likes: 59, Points: 58, Legacy Rep: 680
    Location: europe

    peter radclyffe Senior Member

    whenever you see something floating, fasten it to the raft, why stop at 200 miles, you can make it the adventure of a lifetime, time mag can sponsor you and you can keep going till you meet that pacific plastic nirvana swirl, a webcam can be beamed to every school, to show them the plastic nightmare that is our world
     
  12. djwkd
    Joined: Jul 2006
    Posts: 380
    Likes: 2, Points: 18, Legacy Rep: 51
    Location: Newcastle-Upon-Tyne

    djwkd Senior Member

    I know its probably too late, but i wouldn't go with the storage boxes.
    Someone else used these and err...sank.
    He was OK, because of the wonder that is PFD, but...
    You could use those plastic boxes and fill ALL of them with foam and plastic bottles, and that would be fine, but not just on their own.

    Hope i helped (though i was probably to late to do so), Dom.
     
  13. peoplethought
    Joined: Jan 2010
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: clearwater, fl

    peoplethought New Member

    Is it weird that I just signed up to ask this question and noticed this thread already at the top of the list? If you sealed the lids on the Rubbermaid containers with marine adhesive would that not make them water tight?

    Is there a specific kind of plastic that can hold up in ocean water? I have a relative who has a garage full of unused Rubbermaid bins, some trash cans and cat litter boxes - the plastic boxes the litter itself comes in when you buy it. I was thinking I could seal all these containers up, build a wood hull and fill it with the containers.
     
  14. djwkd
    Joined: Jul 2006
    Posts: 380
    Likes: 2, Points: 18, Legacy Rep: 51
    Location: Newcastle-Upon-Tyne

    djwkd Senior Member

    Hey peoplethought,

    Yeah, it would make them watertight, but be expensive (probably).
    HOWEVER, it's good that your making use of stuff that might'nt otherwise be used.

    I would imagine that all plastic would be fine in ocean water. If weather were very rough, it would smash up, like anything, but i wouldn't think any reactions would take place.
     

  15. peoplethought
    Joined: Jan 2010
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: clearwater, fl

    peoplethought New Member

    If the boat were 10 x 30, would it be cheaper to make a watertight wood hull? I was going to make a frame to contain all the bins, and for the planking just use cheap wood or some other material.

    I think it comes down to figuring out how much sealent I would need to seal all the bins.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.