I made a set of Yost-type bags with the polyester-reinforced vinyl (like Coverene). Aside from doing a constricted hourglass modification where they pass through bulkheads, they were as described. One is 18-oz material, and the other is 10-oz IIRC.

They are 8 months old. They have never lost any air! I was shocked to discover this yesterday, when I took the multi-chined Sea Rider out for its... 2nd paddle. (I just can't stand the sitting position; I couldn't even get in 4 miles before cramps and desperation set in. But, GPS made it out to be quite efficient, as I'd always suspected.)

So, I can't say much about the bags _in_use_. But, sitting idle, they've sure held up. But, I'm not sure it's worth my time and non-enjoyment to make them. I bought bags for the Sea Otter, which I will transfer to the Sea Tour, when it's done.

: I have been making float bags from clear vinyl with mixed results.
: Most seem to develop a leak after a while. None of them will
: stay inflated for 2-3 day but that is not really an issue. I
: have had a couple develop holes where I assume they were in
: contact with the frames.

: So I am considering using the heat seal nylon now but wanted to get
: input on what you use and how they have held up. How hard they
: were to make, any other info you could offer.