Custom ultra light float tube

Discussion in 'Fly Fishing Forum' started by Rory McMahon, Feb 6, 2012.

  1. Hey everyone,

    I've been trying to design an ultralight float tube after I've given up on any company making one. I've tried to find a small independent ultralight backpacking company that would build one for me, but no luck there either.

    I've been toying with a few ideas, I was hoping I could use an existing bladder and build a cover around it, this was before I found out that the bladder is about half the float tube weight (2.98lbs for bladder, 3.89lbs for cover). So now I want to make my own bladder and cover.

    For the bladder I found a website saying that mylar is sometimes used for inflatable bladders, this would definitely be the lightest, but I have some concerns about durability. Do you think it would pop like a balloon if it were to be punctured? I wouldnt want to be in the middle of a lake and have my float tube blow up.

    PolyUrethane is a common material that is supposed to be pretty light. Can't really picture it though, I'd need a sample to figure out how light it would be. Any one have an estimate for how heavy it would be in comparison to mylar? All other aspects seem great with PU.

    The last material im considering is nylon (vaccuum packing material), seems pretty lightweight and strong, it doesn't puncture easily (just deforms), and it would probably bond together pretty good.

    The cover is where I was hoping to save the most weight, my current float tube is made out of 420 denier nylon (6.8 oz per sq yard), and 1000 denier cordura (10.8 oz per sq yard). I think those materials are overkill, I don't need my float tube to withstand a bear attack. The two dangers I see are algae covered sticks or rocks that you can kick into, and a hook catching on your tube will release or fighting a fish. The second one has me worried. I figure I just need a material that will keep the hook from hitting the bladder.

    I looked into cuben fiber, its light (around 1 oz per sq yard), very abrasion and puncture resistant, but I'm concerned about a hook going through and hitting the bladder. I don't really need the waterproof properties it has. Anyone know of a comparably light material that would keep a hook away from the bladder a little better?

    If anyone has any experience with this kind of project I would appreciate your input. I have never done any heat welding nor do I have a set up to do it. I know gluing is one method, but I don't know if Id trust it to hold air. I'm hoping to get a float tube under 3 lbs out of all of this. Currently mine weighs 7.87 lbs when its dry, that's just too much when you're trying ultralight. That, combined with waders and flippers almost triples my pack weight for a weekend trip.
  2. I like the idea of all that R&D. If you made it happen you'd probably have some very interested mfr's in your design. Hear that about the weight...that's part of why I'm still in a death donut (5 lbs total). Can't contribute much in the way of ideas but definitely wear your pfd if you get something on the water. I guess give that some thought if your primary plan is hiking with it and weight is a big consideration, as in does a pfd fit into that equation (home made tube + remote water - pfd = not worth it). Hope you come up with something!
    Olive bugger likes this.
  3. I see where you are trying to go with this but I think safety should be the main ingredient-especially at high elevation. I have fished a number of high lakes up to around 11,800' in the Sierra and even in late July the water is damned cold. You don't want to be in that stuff a couple hundred yards from shore with a deflated tube draped around you.

    I have had a tube go flat and it is no fun. I was fishing a small private lake for cutthroat one day and using my old Caddis tube with the monstrous truck tire innertube in it. I hooked a fish that somehow didn't feel like a cutt and stripped it in only to find that a bullhead catfish had taken my fly! When I took it off the hook it slipped out and landed on my tube. The spine on the fishes back went into the tube and it immediately began to blow out air and bubbly slime while the fish was stuck there. I got rid of the fish and started kicking to shore which was only a short distance away. Even with my finger in the dike I was still chest deep in water by the time I reached shore, only the aux flotation in the backrest kept me afloat. I haven't gone out without a PFD since.

    If you are going to do some R&D how about giving some thought to inflatable waders? :D That could kill two birds with one stone and save room for a PFD besides!

  4. Roy, I think many of us back-country fisherman have had the same thought. I think one of the best ways to reduce the weight would be a bladder-less design.
    If you have ever had the opportunity to use an alpacka raft, a v-tube out of that material would clearly do the trick. I'd keep each tube as a separate chamber with
    an inflated seat for a third. Check out some of the fabric's at seattle fabric. I've been thinking of gluing up something out of their vinyl coated nylon myself.

  5. Get a pack raft and cut out the bottom then rig some sort of harness.
  6. Ive I'm only buying that story because it's you.
  7. I do like the idea of using raft material. To all those concerned about safety, I just don't see how an ultralight float tube is much more dangerous than an ultralight raft in terms of being punctured. If anything a float tube may be safer if you use multiple chambers. Don't get me wrong, safety is a major concern, but theres ways to have something be lightweight and safe enough.

    Anyone know what material is used in the ultralight rafts (alpacka, curtis, etc.)?

    Another idea would be taking a raft, and basically welding in built in waders. That way you could stick your feet through the bottom and use flippers. I could see that being pretty shitty if it was raining though. The legs would be like the bottom of a funnel.

    A v tube made out of raft material seems pretty ideal. I could definitely get that under 3 lbs.
  8. You might email Brian Curtis and solicit his input. He may even provide a copy of plans for his Curtis Raft. No longer in production and coveted by the few lucky b'tards that have one. Butter him up good. Several guys here are good friends of his, Kent for one, SG & Smalma too ithink, and could provide contact info.
    Best of luck. This would be a salable item done well.
    Kent Lufkin likes this.
  9. Old schools Bucks Bags Caddis tubes are really light, and there are various bladders systems available that fit the light weight bill nicely (and can be inflated by mouth, eliminating need for a pump). Why reinvent the wheel?
  10. My Curtis raft is a lightweight urethane coated nylon. Lighter than backpack cloth, about the same weight as the waterproof floor coated nylon material in a tent floor. I think it runs about 4 oz. per square yard. I think the seams are glued, but maybe they are electronically welded. There is tape over the seams. I think a float tube and waders of this weight material would be a good fit for backpacking. The single air chamber feels like the weak spot in the Curtis raft, so it's important to have a thermarest or some kind of foam floatation in it, for safety and as insulation from the cold water of the lake.

  11. [/QUOTE](I did it as long as I could Kent but) After being diagnosed with arthritis in my hips I haven't carried the WM Kodiak into anymore backcountry lakes. I'm not quite with you on the inflatable waders Ive but safety is a big concern for me too. I have a friend with a Flyweight raft and it doesn't work real well as a fishing platform even using hand paddles. He uses it mainly for going from one point of land to another. For a difference of 5lbs to 9lbs, an Outcast Trinity or an ODC 420 UL with flyweight waders, fins, and possibly a cheap pump would work for me better than a pack raft and paddle(s). The only reason a tube might not work is for lack of room in my pack on an extended trip. Now I'd be interested in a packraft manufactured with a seat but no floor, but I'm not going to carve up a $300-$900 Flyweight or Alpacka myself.
  12. The curtis raft is made from a heat seal-able nylon (possible 70Denier), The FlyWeight Designs FlytePacker is of 200 Denier Urethane Coated Nylon (heat seal-able).
    Both have heat welded seams with the curtis raft using a taped seam and the Flytepacker using a seam with out tape. As for the Alpaca, I'm not sure of the fabric
    but is is a glued tape seam which is something you could do with a vinyl coated fabric. Many of the fabrics can be found locally at
  13. Check out some of the Mylar sail materials out there. Very strong and super light. Quantum sails has a loft in Seattle that does a lot of design work and would probably work with you.

    On the safety factor cOnsider double tubes so you can always limp home.
  14. I packed the flytweight and alpaca from the gear program over 30 miles into the Enchantments Wilderness last year. The flytweight is perfect for high lakes and it is incredibly light. I personally would buy the alpaca because it's increase in weight allows the opportunity to run any river water you want. It also tracks well while rowing. A lot of people complain about not being able to kick with their feet. But, most alpine lakes where a lightweight craft are beneficial are colder than an Eskimos a-hole.

    I have heard that alpaca is developing an open floor platform. Can't wait to try it out.
  15. I went to seattle fabrics and looked at some materials. I believe I looked at some 200d urethane coated nylon and wondered if it would hold air. If thats what flyweight uses, and I've never heard anyone complain about the material leaking, then it must work. I take it the urethane coating makes fabric 100% waterproof and air tight?

    On I found a material that is nylon coated cuben fiber. It's 2.92 oz per sq yd and is apparently very tough. It's waterproof, but I don't know if it would hold air under pressure. I sent an email to get some more info on it, but I know he isn't an expert on air bladders.

    I think I may have to buy some of the 200d nylon and make a small air bladder and see if it would work. Now the tricky part is figuring out how to seal the seams..
  16. Playing devil's advocate here but I'm assuming the rest of your backcountry gear is lightweight as well? Is there a way to drop 3lbs elsewhere and not comprise on the quality of the fishing gear? Bivy sack vs. 2 man tent, a different pair of waders or a lighter weight stove and fuel. I personally will hike with 5-7lbs more on my back to have some creature comforts, which may include an extra beer or 2.

    Last question, and this boarders on being an a**hole but what kind of shape are you in? The reason I ask is I always see cyclists who are 25lbs overwieght trying to shave grams off thier $5k bikes when I think to myself maybe they should maybe skip the cheesecake (again, not trying to be an a** with this comment but I honestly think its worth asking).
  17. I don't know if this applies to anyone else, but I see it applying to me. I'm not a weight weenie, but I've spent time with some that are. Drilling holes in things, ripping out tags, removing logos and such. The first place I need to shave weight off is not the gear I carry or my pack, it is located on my person, just north of my belt. I can make anything easier by dealing with that first. Very good point, and I'm taking it as great reality, not you being an A-hole!
    Bill Aubrey and Kent Lufkin like this.
  18. I think there two components to this discussion. For me, on overnighters it no contest--light weight pack raft. I just can't fit my camping materials and a tube/waders/fins in a pack that I'm willing to carry.
    Day trips its a different story. Having the ability to fish and propel at the same time makes a float tube a preferred method. My tube weighs in at 7lb plus waders and fins. So the discision I have to make
    for day trips is more base on the terrain and do I want to go light or heavy. If one could get a tube down to the 3lb range (I assume the lighter material would also reduce bulk) that would start to blur the lines.
  19. Raises a very valid point. The odds of something weighing, say, 3 lbs safely supporting the majority of us are likely slim at best (sorry for the pun). North of 220, where a roundie is no longer an option, the first priority has to be weight capacity. If under 220 I think you'd be hard pressed to outdo the features of a roundie at 5 lbs, not to mention the dirt cheap cost of them anymore. As of today a 3 lb craft with any reasonable degree of safety, durability, performance and cost (I'm still leaving out weight capacity that accomodates most guys) is still a massive pipe dream.

    Rory, we're counting on you to fix this...
    dbfly likes this.

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