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  #1  
Old 06-28-2010, 04:17 PM
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kroberts kroberts is offline
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Flat bed hovercraft trailer deck.

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.
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Old 06-29-2010, 05:48 PM
Stumble Stumble is offline
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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.
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Old 06-29-2010, 08:09 PM
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kroberts kroberts is offline
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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.
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Old 07-01-2010, 12:33 AM
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pistnbroke pistnbroke is offline
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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 ......
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Old 07-02-2010, 09:51 AM
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tinhorn tinhorn is offline
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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.)
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Old 07-02-2010, 03:42 PM
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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.
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Old 07-04-2010, 06:02 AM
RussellC RussellC is offline
 
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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
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  #8  
Old 07-04-2010, 06:32 AM
apex1
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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
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Old 07-04-2010, 11:12 AM
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kroberts kroberts is offline
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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.
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Old 07-04-2010, 08:02 PM
apex1
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Quote:
Originally Posted by kroberts View Post
OK, so let me ask a couple questions about it.

Is it UV resistant?

yes


How is the surface for standing on it, when you have a wet deck?

a bit slippery

How does hit handle a landing skid hitting it?

no prob.

Does it take paint?

not

How does it handle wear from sand and rocks being ground in by the skids?

for hundred years at least

What sort of place do I look for it in any size that would be useful for me?

No idea, I live in Germany


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

Regards
Richard
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Old 07-04-2010, 09:10 PM
Squidly-Diddly Squidly-Diddly is offline
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could a tarp stretched over metal frame work?

with frames about 16" apart?
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Old 07-04-2010, 10:02 PM
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kroberts kroberts is offline
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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.
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  #13  
Old 07-04-2010, 10:10 PM
apex1
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Solid wood planks, ext, house paint, and a 4 mm layer of HDPE, there we are.
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Old 07-04-2010, 10:28 PM
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kroberts kroberts is offline
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That's got possibilities.
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  #15  
Old 07-05-2010, 08:30 AM
Tug Tug is offline
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http://www.fishhousesupply.com/icehouseframes.htm
One of these trailers would make loading/unloading the craft easier...
Tug
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