raft armor

Discussion in 'Boat Design' started by snakeclaw, Sep 21, 2011.

  1. snakeclaw
    Joined: Sep 2011
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    snakeclaw New Member

    i'm trying to armor my rafts to enable them to sustain a bit more damage than they do. has anyone done this successfully?
     
  2. Squidly-Diddly
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    Squidly-Diddly Senior Member

    SeaEagle and Sevylor sell "boots" to cover their rafts.

    also supposed to add performance.

    I don't see why you could'nt make a homemade, out of just about any sheeting or fabric.

    inflate raft, cover with thin plastic, then your fabric, and safety pin all nice and snug, then slather on liquid plastic like they use to make rubber gloves.

    The thin plastic should keep it from sticking. Test first.
     
  3. kach22i
    Joined: Feb 2005
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    kach22i Architect

    If it has a rigid bottom, you might try a thin sheet of low friction HDPE plastic.

    Based on my experience with hovercraft skirts, I can state that the higher the tension/pressure the easier it will be to cut. For instance, when trying to cut fabric it's best to stretch it taut first, then cut.

    This gives me an idea.


    ...................................new outer membrane (low tension)
    _ _ _ _ _ _ _ _ _ _ _ _ _ _thin flexible foam layer (spray glued)

    --------------------------inner high pressure original membrane

    I've toyed with the idea of a external protective mesh or mail armor of some kind before, could be nylon in lieu of aluminum or stainless steel. The weight issue along with flexibility sort of kills it every time I do more than daydream about it.
     
  4. portacruise
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    portacruise Senior Member

    You can try to make them very slippery so that abrasion damage is minimized. Application of "armor all" or some other brand of PVC protectant that stays slimy on the surface lasts one or two excursions for me. All other alternatives that I know will add weight or hassle, defeating the purpose of an inflatable.

    Porta

     
  5. Petros
    Joined: Oct 2007
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    Petros Senior Member

    If your raft has particular locations where it is more susceptible to damage you could just glue on large "patches" of heavy fabric (similar to the hull material) in strategic locations. These could be "sacrificial" patches that you just repatch or replace when they get beat up.

    If you use the same type of fabric as the hull you can use solvent type adhesive, though this would make it difficult to replace later. OTOH, if you use contact cement you can remove the patches with a heat gun when they get beat up and need replacement. You are also not limited to the same type of fabric with contact cement. You could even use leather, kid skin or elk hide are some of the most abrasion resistant materials known, better than synthetics. I once tested a lot of different fabrics for abrasion resistance, kid skin and elk hide are hard to beat.

    Hard plastic skid plates as suggested I think would add extra hassel/assembly time and there would be no reliable way to hold them in place. Straps or ties would get caught and damaged, gluing them on would run the risk of having the raft get caught or even tearing the hull fabric.

    Good luck.
     
  6. kach22i
    Joined: Feb 2005
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    kach22i Architect

    1. The patches idea is a good one. There are also rubber paints made for recoating rafts.

    2. If there is already a rigid floor, thru-bolts along with some sort of mastic would be the most secure method of installation.
     
  7. snakeclaw
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    snakeclaw New Member

    there are patches available, and one of my rafts actually does have those. i think they are called "skid plates" or "rub rails" or something like that. they are below the tubes and actually do protect the tubes since they have never torn there. its just another layer of material glued on. the floor, however, is a different story. in the 3 years i've owned it, i think i've patched 12 to 15 times. considering where i've gone with the boat, its not that surprising. doing the arkansas river in colo while at 1100 cfs tore 5 holes in one 16 mile float. the water level was low and the current swift and the rocks are all pretty sharp.
    i suppose i could glue another layer of hypalon on the floor, but weight is becoming an issue already. just as it is its about 100 lbs and its bulky to move about deflated. if i glued another layer onto the floor i would add another 20 lbs to it, not to mention that stuff is pricey, and it would only give me a bit more protection.
    FYI, i'm trying to take this raft where kayaks and canoes typically only go. There are white water creeks in arkansas that are just beautiful but many would destroy a raft as it would be non-stop scraping and poking from rocks and branches. its an interesting problem and i'm really trying to not haul kayaks and canoes on my roof. where do you put a cooler with 100 beers and camping gear in a kayak? maybe a canoe, but then those swamp all the time where i like to go.
    the HDPE plastic is interesting but it seems rigid and if it were to be thin enough to be flexible, it would be too brittle, in addition to figuring out how to fasten it.
    i LOVE the idea of kid skin and elk hide, not to mention how cool that would look. but again....i'm guessing that stuff isn't light or cheap.

    i'm not fond of the skirt idea that sea eagle uses. i'm thinking water is going to get in there and it will become a snag issue. a sheet of hypalon that size would cost more than i paid for my boat.
    thanks everyone. one of these days i will figure it out.
     
  8. rwatson
    Joined: Aug 2007
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    rwatson Senior Member

    Whats wrong with the good old raft standby - inner tubes ?

    Partially inflated, and wrapped under the edges, they would add buoyancy and create a buffer. When punctured, they can just be replaced.
     
  9. Petros
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    Petros Senior Member

    when dry it is actually lighter than heavy hypalon or hull fabric, price is high but you do not need pretty looking hides. find a tanner or a hunter and get his "seconds", one hunter i know gave me 4 or 5 deer and elk hides because he has been saving them and had so many he ran out of things to make with them. Too good to throw away, so he gave them to me since he was tired of storing them.

    Any armor you add will contribute to weight or bulk, but all of the repairs and patches will do the same and not be as reliable as just patching or armoring the hull before you go on a float trip.
     
  10. portacruise
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    portacruise Senior Member

    If its the bottom that's taking the wear, you might consider something similar to an inner tube bottom. The bottoms are meant to protect a tuber's rear end from rocks. The bottoms are made of about 1/8" tough, flexible polypropylene? or something similar to stiffer truck mud flap material. Holes are punched around the circle and fastened to the tube bottom with strong cord or big zip ties. Very light material that lasts forever and it floats.

    Porta
     
  11. kach22i
    Joined: Feb 2005
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    kach22i Architect

    When I used to take my hovercraft out to shallow rivers and creeks I'd see canoes and kayaks too. I would just skim over sand bars and rocks. Larger rocks and branches would still be a problem though.

    http://hoverclub.invisionzone.com/forum/index.php?showforum=24
     

  12. snakeclaw
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    snakeclaw New Member

    great suggestions and i'm trying to calculate the merits of each. the inner tubes are a fun idea but they will have to be strapped on and the straps themselves would serve as potential snags as i drag across rocks and roots. and when an inner tube bursts i'm either patching or carrying several extra inner tubes.
    i'm still cracking up about that animal skin. funny stuff. my concern there is that there will be not just one skin but many skins and they will have edges. IF they are sewn together, then certainly they will tear apart at this seam when dragging across rocks. if you can imagine two 250 lb guys and a cooler sitting on the bottom of a raft and dragging across many feet/yards of a rocky creek bed...grinding...and having this happen every few minutes...for hours. that is an extreme example, but on some creeks, that is the reality. kayaks and canoes can do this sort of stuff.

    i keep revisiting the idea of that HDPE. its already in use on the bottom of hard bottom boats, impervious to water, and it floats. maybe there is an angle there.
     
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