Flat bed hovercraft trailer deck.

Discussion in 'Materials' started by kroberts, Jun 28, 2010.

  1. kroberts
    Joined: Mar 2009
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    Location: Chicago area

    kroberts Senior Member

    Hi,

    Hope this isn't too far off topic. I have a hovercraft. It's licensed as a boat, so I hope that's close enough for you guys. :)

    So the problem is, hovercraft of the type I use have flatbed trailers. This is really handy in most ways, because then you not only have the hover but you also have a flatbed trailer.

    The problem is, it's a PITA to keep decks on it. I usually use a treated or exterior plywood with some paint splashed on.

    What I have is a converted boat trailer. It started life as a typical 3" square tube Y frame trailer. The cross braces I rotated so the whole works lays down flat, and then sheets of plywood cover the works, oriented sideways so the entire width is one sheet. There is steel support every 2 feet, and there are supports on the outside edge including a flat of steel which follow the top view of the hovercraft, about 3 inches bigger than the hull all the way around.

    This is not a high load situation. The hovercraft weighs 1000 lbs (USA measurements) and the trailer not that much.

    What I'm after is a way to deck this thing so it's both affordable and durable. I've considered putting C channel around the outside and either putting 1" marine plywood in there, or the same sort of treated planks you use on the deck of your house, it's what we call 5/4x6 inch deck plank. It's actually 1"x5.5". If I do the latter, I'll need to put some sort of silicone caulk or similar to seal up the cracks and still allow for expansion. If I go with plywood, I can just leave enough room for the boards to expand as I cut it.

    Anyone have any recommendations for a specific plywood, or a specific plank, or any other type of material? I'm tired of putting decks on an otherwise perfectly good trailer.

    Oh yeah. Sometimes this thing will be dry loaded, but sometimes it goes in just like a boat trailer. So figure for a boat trailer, and the landing skids on the craft are wood covered with Kevlar.

    Thanks.
     
  2. Stumble
    Joined: Oct 2008
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    Stumble Senior Member

    No plywood, even marine plywood will stand up to submersion moistute for long. The definition of marine ply really has to do with the quality of construction, not the rot resistance of the wood itself.

    My first thought would be to use some 1/8 aluminium sheets, or just some cheap diamond plate panel from Lowes. If you need more durability then deck it like a porch with 2X10 preassure treated lumber.
     
  3. kroberts
    Joined: Mar 2009
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    Location: Chicago area

    kroberts Senior Member

    It doesn't exactly stay wet, unless you park it flat and let rain hit it. I park it indoors due to a city ordinance that twists my underwear in a knot. Can't store anything outside unless it can legally drive down the road under its own power. WTF?

    Anyway, the cost for any type of diamond plate I've found is way over my budget. Best I've found is around $350 for a 4x8 sheet, and I would need almost 4 sheets. And this is a 2000 lbs axle. I could trade that up, but why have a trailer that weighs more than the thing it hauls?

    Anyway, you've basically reiterated what I've heard elsewhere so far.

    Thanks.
     
  4. pistnbroke
    Joined: Jan 2009
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    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    I note that many of the flat tilt trucks use steel plate for the bed so why not go for 1/8 steel plate..cheaper than aluminium and if the rear one goes extra rusty being in the water just swop it with the front one ......
     
  5. tinhorn
    Joined: Jan 2008
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    Location: Massachusetts South Shore.

    tinhorn Senior Member

    I'm wondering why you need a solid deck. I, too, have a "converted" boat trailer that I use for all kinds of inglorious hauling, and if my load won't fit on the bare frame, it WILL fit on the two 4x6 timbers I bolt to the frame. (I keep some 2x4s and nails in the pickup in case I need some crosspieces.)
     
  6. kroberts
    Joined: Mar 2009
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    kroberts Senior Member

    This is for a hovercraft. An air cushion vehicle. It lifts by pumping air under the hull, and inflating a skirt around the outside to prevent air loss. Typically under operation, there is about 1 cm air gap under the skirt, where air escapes.

    If the deck is not solid/airtight, the craft won't be able to fly off the trailer.

    Thanks.
     
  7. RussellC
    Joined: Apr 2010
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    Location: Melbourne Aus

    RussellC New Member

    Try HDPE sheet

    You may need to hunt around but HDPE sheet can be bought for as little as a $1.00 dollar a square foot for .125" and $1.50 for ¼" sheet its used in very large sheets (typically 20' by 300') as dam and rubbish tip liners and other agricultural uses so hunt around a bit.

    a first off may be to try sani-armour

    Russell
     
  8. apex1

    apex1 Guest

    Let me second that.

    HDPE is a perfect solution for that deck. It has a weight of about 10kg m² @10 mm, which is about the thickness you will need.
    Pricewise it should be similar to a outdoor ply.

    Regards
    Richard
     
  9. kroberts
    Joined: Mar 2009
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    Location: Chicago area

    kroberts Senior Member

    OK, so let me ask a couple questions about it.

    Is it UV resistant?
    How is the surface for standing on it, when you have a wet deck?
    How does hit handle a landing skid hitting it?
    Does it take paint?
    How does it handle wear from sand and rocks being ground in by the skids?
    What sort of place do I look for it in any size that would be useful for me?

    Thanks.
     
  10. apex1

    apex1 Guest

    Hope you don´t mind, that I answered in your post.
    Sources should be easy to identify.

    Regards
    Richard
     
  11. Squidly-Diddly
    Joined: Sep 2007
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    Location: SF bay

    Squidly-Diddly Senior Member

    could a tarp stretched over metal frame work?

    with frames about 16" apart?
     
  12. kroberts
    Joined: Mar 2009
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    Location: Chicago area

    kroberts Senior Member

    Members are 24" apart.

    Richard, I have no problem with you answering my posts. You are a known quantity.

    I googled it, I figured I would need 1/2" or so. Quite a bit more expensive than plywood actually, probably out of my budget.

    Thanks.
     
  13. apex1

    apex1 Guest

    Solid wood planks, ext, house paint, and a 4 mm layer of HDPE, there we are.
     
  14. kroberts
    Joined: Mar 2009
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    Location: Chicago area

    kroberts Senior Member

    That's got possibilities.
     

  15. Tug
    Joined: Aug 2007
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    Location: Muskoka,Ontario,Canada

    Tug Junior Member

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