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Custom ultra light float tube

41K views 157 replies 52 participants last post by  slimjones 
#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.
 
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#61 ·
"Lord Vader, your float tube is ready..."

<cue Imperial March>



heh...

I need to make another grey one so I can have two others flanking me at all times! :)

The seat has yet to be attached and I still have to trim the seams and add the attachment points etc. but the whole shebang as seen here is just over 30 ounces - still under the two pound mark - tape, excess fabric, and all.

_SHig
 
#64 ·
This is prototype 2 with a few seam design changes and manufacturing process updates. It's not "dialed" yet - two steps forwards, one step back sort of thing... But I think it's very close.

As for production I still haven't decided if that's something I'll be pursuing or not. PM me offline if you might seriously consider purchasing one.

_SHig
 
#66 ·
Here's the newest in the ongoing saga of the Packin'tube...

So you recall the Lord Vader tube - pretty black fabric, very lightweight, and I had changed the seam profiles of the back of the seat and the inner diameter of the "U" section to be faceted to ostensibly facilitate the connection between the two parts.

Well, you win some, you lose some. I had a feeling that the apexes between the straight line segments on the "U" would be stressed, but I didn't go with my gut so basically at high pressure, the urethane coating delaminated under the localized stress and the fabric became porous. Instead of sealing up the fabric with glue on the outside, I wanted to "keep it clean" so I simply, and again against my better judgemet, moved the seam inward to get some "new coating" at the apexes. At any rate, this sealed the bladder, but the stresses were still there and when I put some lung into it, I got the dreaded POPssssssssss...

I guess I lost this one.

Anyway, I wasn't really completely satisfied with the geometry of the "U" and I was making compromises because of this so I took this opportunity to tweak the pattern and go for Prototype #3.

Voila! (I'm sad that I don't have any more of the Vader black fabric, but this blue is still pretty sexy...):





I feel MUCH better with the new geometry and I believe that it'll work out well. I also went back to the simple radii and think I have a good connection design.

Here's the package as-is with a ton of fabric left to trim off:



I'm bummed that it's crept up over the magic two pound number, but this fabric is a bit heavier than the black, and I think there should be a couple of ounces of scrap that I can shed to bring it back down.

BTW, here's what the thing packs down to, and with some compression, it can go smaller, though I think it's sufficiently small as is, no?





At any rate, I'll keep plugging with this new prototype. Things are very promising, but of course my engineer mind won't let me leave things be and I'm working on a new list of things to tweak...

It never ends!

_SHig
 
#71 ·
Big milestone today!!

I finally permanently attached the seat to the "U" section. One of the biggest difficulties of doing this is that the length of the arc around the inside of the "U" is much shorter than the length of the arc around the back of the seat (when deflated). When inflated the two arcs should be the same as the back of the seat puckers up and pulls in.

What I originally envisioned with the Vader Prototype was to have 5 segments to break up the arcs into the same percentage of the total curve and then weld them on center. The problem that I discovered in reality was that with only 5 segments I couldn't geometrically "pucker" the back of the seat without overlapping with the adjacent segment. Sheesh, this is hard to explain...

At any rate, with the newest Gen 3 (Hmm... Navy blue, Higashi Navy, Higashi Maru?) I broke up the two arcs into 15 (!!) segments which allowed a nice even pucker.

Check it!



Here is the assembly with the seat fully deflated. You can see even if the seat gets harpooned by a Lake Davis pike, you can still sit low and wet in the sling and kick home.



And here is the thing fully inflated with a temporary spread limiter installed. You're looking at the bottom of the tube here... The real deal will of course be cleaner! :)



Flip side (the side you sit on!):



Prototype fleet! (OG Proto1 is rolled up awaiting orders...) You can see from this photo that I've repaired Vader. Sure you saw his Tie Fighter go spinning out of control into deep space, but you couldn't REALLY have thought that you wouldn't see him again in the sequel? The repair allowed me to experiment with seam geometries, and though these tweaks most likely won't end up in the production model, data is data.



Next step on Higashi-maru will be to finish trimming the seams, install the spread limiter strap, the valve plug leashes, and glue on the attachment points.

Until I actually "take the plunge" I won't know if there are any further design details that I'll want to make on the next one, but so far from the looks of it I think I'm pretty damn near done with the design of the air holding system.

Ah progress!!

_SHig
 
#73 ·
Mark, buddy! ;)

I haven't decided whether or not I'll be making any "friend" units or not.

I'd be quite put out if I climbed to my bucket list 10,000' lake to find a fleet of these floating around in it! :)

Seriously though, if you were to really want one, shoot me a PM so I can gauge the level of interest.

_SHig
 
#77 ·
Okay, I think it's ready for the pool or pond!

I trimmed the extra fabric and I'm flabbergasted by how much weight and bulk I was able to lose!



WELL under the magic 2 pound barrier! The lunker high mountain trout will weigh more than the boat! :)

And check out the tidy package!!





This'll hardly take up any space in a pack. Stoked...

Details...

Valve leashes:





Spread limiter (and what you might want to stake the boat down with - it'll fly away at the lightest of breezes!):





And the cockpit!:





One thing I noticed that just in the few minutes I was outside taking these photos the boat got very "ping tight"! Rang like a drum. Must be careful to monitor the pressure... Wish there was an easy and light blowoff valve, but I did the calcs and it should be able to take any sun heating pressure increase easily. Still, you can understand my trepidation... ;)

_SHig
 
#80 ·
SHig,

Outstanding! Time for a shakedown cruise and then your patent application. Just think, you'll be president, CEO, CFO, right down to janitor as you become the titan of the ultra-light float tube universe! Congratulations on your project. It's fun to see the germ of a thought taken through development and final success.

Sg
 
#81 ·
I went down to my local "pond" to test out the new boat. I did my best to try to fall out and I failed. I inflated it on shore then hopped in and it immediately tempered - lost pressure due to cooling down. In this less than tight state it was a bit wobbly with how high I sit. Felt a bit like balancing on a ball side to side. Front to back was fine. A quick few breaths to tighten the skin and back in the drink.

MUCH better. Definitely not as solid feeling as my Fish Cat but that's to be expected because of the way the seat is attached to the "U". It does allow some roll, but I think it won't be hard to get used to. Feels kinda like sitting in a canoe or kayak, especially at first when the pressure dropped. Still, no risk of actually barrel rolling.

I'm WAY out of the water - probably A good 3", pretty much what I had designed for. I can make do with pants waders, no chest waders required.

Anyway, photos:











I made some fly casting motions while I was at it and it was a no-drama affair - not that I had expected any.

I'll have to take my gear next time I hit the "pond". ;)

_SHig
 
#84 ·
Are there any trout in that there pond?

Looks like an excellent fishing platform you have there! Looks like comfort and effectiveness will exceed the Curtis high lake raft. Congratulations!

Sg
Trout, lol!

I actually got a lot of advice from the man Curtis himself. Have to give him credit for sharing his tips and tricks of working with this material. It was cool to be able to bounce ideas off of him.

I've been trying to get a hold of Del Canty with no luck. Anyone know him personally?

_SHig
 
#88 ·
I just recently found and read through this thread and have been thoroughly impressed with the development of this ultralight tube and all that SHigSpeed has gone through in the process.

You, sir, are the da Vinci of float tubes! Major props! :)
 
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