Ultralight float tube for fishing

[Scott Higashi]

Ive been working on my own ultralight fishing float tube for the last few years and now that it's nearly done, I figured I'd share the project here.

I've been blogging in at the site below if you'd like to see it from the beginning;

http://www.kiene.com/forums/showthread.php?21680-SHig-s-Superlight-Packin-tube-Project

I'll copy th emost recent posts below to show you where I am as of now.

****************

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!

http://farm8.staticflickr.com/7047/8689915538_eab1bc4fe8_b_d.jpg

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

And check out the tidy package!!

http://farm9.staticflickr.com/8396/8688822785_efdac82e02_b_d.jpg

http://farm8.staticflickr.com/7051/8688821085_c886d20df9_b_d.jpg

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

Details…

Valve leashes:

http://farm9.staticflickr.com/8126/8688973685_718cd2992b_b_d.jpg

http://farm9.staticflickr.com/8536/8690090552_3ee52baa87_b_d.jpg

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

http://farm8.staticflickr.com/7052/8690087684_e2d929b7b4_b_d.jpg

http://farm8.staticflickr.com/7056/8688986077_a55dcab5c8_b_d.jpg

And the cockpit!:

http://farm8.staticflickr.com/7053/8688983115_60fed3c560_b_d.jpg

http://farm9.staticflickr.com/8115/8690096266_1e045d1352_b_d.jpg

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… ;)

[Scott Higashi]

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:

http://farm8.staticflickr.com/7048/8691279068_4d6e9c2302_b.jpg

http://farm9.staticflickr.com/8118/8690163763_eb4ce3fb7c_b.jpg

http://farm8.staticflickr.com/7052/8690155155_18676dc0c0_b.jpg

http://farm9.staticflickr.com/8102/8691269660_7034f78385_b.jpg

http://farm8.staticflickr.com/7044/8690146743_d4b5e1c92f_b.jpg

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

[Ryan Smith]

Very nice Scott! That took a lot of effort and it paid off looks like. I wonder what the weight savings would be if you put 30d nylon on the top portion as opposed to the 70d. 3oz per sq yd versus 4+oz (just a guess). May be too fragile though.

Ryan

[Dustin Short]

For an inflatable that is designed to see frequent usage around tiny pointy objects (hooks, fish fins…) 70d is probably as light as you'd want to go.

[Dustin Short]

Scott,

In that thread you linked you mentioned various valves to consider. Do you have a source for thermarest style valves beyond the repair kits? I've looked everywhere and can't find something similar (I don't even know what they're called). Anyway if you could steer me in some direction that'd be great. I'm normally decent on sourcing odds and ends, this one has me stumped though!

[Ryan Smith]

Dustin,

Do you have puncture resistance specs handy or are you wingin' it? I would be curious what the difference would be between the two.

P.S.- On the valves, you're looking for TPU or PVC mattress/air valves.

Ryan

[Dustin Short]

I actually wasn't thinking puncture resistance (since neither fabric is that great) but rather poke and tear strength like when the tip of a hook just barely penetrates the coating and then drags across the fabric. My reasoning is this creates a weak seam for stresses to be focused on and creates a wear and tear point of failure.

There are no published specs on coating thickness or puncture resistance that I've been able to find for the DIY available 30D fabric. I do know it's more difficult to heat seal than 70d fabric. Since uncoated 70d ripstop is only 1.5oz/sqyd and 30d is 1.1oz/sqyd that implies there is a 0.9oz difference in coating weight of the 30d vs the 70d using Seattle Fabrics published weights (3.0 vs 4.3).

So yeah I'm kind of winging it, but thinner coating and thinner fabric both point to less durability in abrasion (what I was thinking of specifically) and puncture resistance.

You could probably do some napkin calculations to figure out the thickness of the two coatings based on density and weight but we don't know the specific coating used in the first place so it's all fuzzy logic at best until someone takes the time/money to test it properly or the specs get published unfortunately.

For a savings of 1.3oz/sqyd and based on Scott's final weight of 27oz. Say 1oz is made up by the valve and glue. So 26 oz for top and bottom. 13oz for top assuming symmetrical design. 13/4.3*3 is approximately 9oz. So he may be able to save around 4 oz per side by switching the fabric to the 30d. That's definitely noticeable and may be worth experimenting with despite my durability concerns.

Btw, thanks Ryan for the valve names! I was instantly able to find some valves for sale. Now I just need to find a place that sells in smaller quantities or look into acquiring some samples.

[Ryan Smith]

Agreed – tearing/abrasion was more what I was worried about in this situation versus a direct puncture. Of course, 30d would be less durable than 70d, but maybe still above the threshold needed? Who knows! Would be cool to attempt it, only problem being a failure leads to someone going into the drink. lol

Let me know if you find any of those valves in small quantities. I couldn't 1-2 years ago, so I've been using kite valves instead. Works great, but a little bit ghetto.

Ryan

[Scott Higashi]

Thanks for all of the comments. As much as lighter is better, the seam bond and fabric tear strength of the material is critical. If I was making an air mattress where failure resulted in a bad night's sleep, I'd consider the 30D, but for taking a dunk in freezing water and having to swim home,
I'll be more conservative. :)

_SHig

[Ryan Smith]

Definitely. You could make that same argument with 210d vs 70d though. It's all about weighing the odds and deciding what you think will work. I think you made a good choice with the 70d fabric.

Ryan

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