MYOG packraft idea

Balloons would probably move around too much to provide much shape. Maybe tubes of some kind or even an entire cheap raft would work better. You'd want fabric that didn't soak up water (cordura would NOT be my first choice).

On a different note there was a thread on packrafter.org about beefing up the bottoms of cheap rubber rafts to us as cheap packrafts.

"The worst idea ever to grace the forums?"

Oddly enough some of the worst ideas I have seen here involve home made rafts (I am still waiting for the Cuben version) and balloons (that is for land based mats)but you are the first to combine the two.
Congratulations !!!
Now, go and prove me wrong.

You are better off taking a household iron and some heat sealable fabric and having a go at making something more substantial.

I believe that the Klymit packraft can be had on Amazon for $133 (it fluctuates) http://www.amazon.com/Klymit-LiteWater-Dinghy-Pack-Raft/dp/B00E4KOQE8/ref=sr_1_1?ie=UTF8&qid=1397659671&sr=8-1&keywords=klymit+raft

Okay now for a shameless plug –

Our CrossFlyte is currently available, and if you are so inclined, the inner tube is separate from the outer skin, so if you are good with MYOG, you could make your own skin to go over our tube. http://flyweightdesigns.com/?product=crossflyte-packraft

As Marc mentioned those are probably the two best for the money, even though there are plenty more options out there.

I tracked this down some time ago and bookmarked it but forgot where I saved it.
http://blog.hillmap.com/2013/02/raft-valves-and-dreams-of-homemade.html

In my opinion, the R&D isn't worth the small price for a proven product.

Somehow the Klymit hadn't come up in my searches before. $133 is dirt-cheap, and for that price it isn't worth making my own. The Klymit won't handle anything technical, but I'm only interested in flatwater anyway. Add a cheap paddle and a MTI Journey and the entire setup is 5 pounds and $200, not bad at all. Lighter than a portable suspension bridge.

Also, upon further reflection, the geometry of mapping flat fabric into curving tubes is pretty complicated – the actual construction of the raft shape is more than I feel like dealing with. I'll leave it to the pros. I still kind of want to try the idea, a little, if only because I like the idea of all that redundancy. And because it would be kind of hilarious blowing up 50 balloons and stuffing them inside it. Maybe I'll make one out of my cheap cordura for canyoneering (as in, for actually using inside of the canyons, to avoid swims).

For future reference, if anyone finds this thread and decides to go with this crazy idea, I also considered bicycle tubes. It's another option, but probably too heavy for the amount of air compared with balloons, and difficult to find one that would go all the way around the raft (you might need a 36" unicycle tube or something).

Awww, I wanted to see what you could do with the balloon idea!
Talk about a light raft!
But hey, if it is just a matter of flatwater yer crossing, why not a single truck inner tube?
Not that I know how to fill it with air without a heavy pump, or what such tubes weigh, but plenty of folk do float down rivers on these things!

I'm also reminded of the way Colin Fletcher used his air mattress for Colorado river crossings. That's cool, because it was a dual use item!

If it was me though, I'd also use an inflatable life jacket. I swim well, but drowning is a bummer.

I'm a little sketched out by the inner tube/air mattress ideas in the GC. Colin Fletcher (and Butchart before him) did have luck using an air mattress. But that was also before the dam upstream, when the water in summer was at least 20 degrees warmer. The Colorado is frigid year-round now, and I'd rather have a proper boat. On more temperate water I would be a little more flexible – I've taken a queen-sized air mattress tubing once, and that was pure luxury.

Either way I'm going to get a life jacket, probably the MTI Journey (under a pound). Not inflatable, but as light as it gets otherwise. If you can't tell, I'm a little scared of water…

Resurrecting this idea, as I realize that I really need a second packraft to invite people on trips. And it would be kind of fun to use canyoneering, where I wouldn't want to abuse the Klymit Dinghy that I just got in the mail.

I had a new idea for this – what about making it out of some kind of mesh? My first thought was noseeum, to be truly ultralight, but I was curious if folks have other ideas for a good mesh to use?

I obviously don't need the small holes of the noseeum, it just happens to be the lightest mesh I can think of. It might be worth adding a few ounces for durability. I would question the floor, in particular, if it was made of nanoseeum.

Does anyone have experience with the poly meshes from OWF? They have one labeled "Poly-Med Hand 3.5oz/sq yd". Sounds like it's probably more durable than nanoseeum, and I figure polyester is a better bet.

Another option would be heavy lenoloc mesh, and the raft would still probably come in under 2 pounds.

I think the balloon idea would fail because you wouldn't be able to get the overall air pressure high enough. The other issue would be the tube fabric stretching. Coating doesn't just make fabric waterproof, it makes it stronger and less elastic.