So I just had this idea to make a water bladder from something like polycro… but I wanted to test the idea without wasting all that time. I happened to see an empty subway bag laying on the floor and the light bulb went on!

And all you need to make it is this:

Unfortunately the subway bag already had a pinhole in it before I even started but it proved the idea could work. What I hope to do maybe tomorrow is make a bladder from poycro and use the same closure cap. Basically all you do though is thread the plastic through the hole in the cap, pull it down over the threads on the bottle and then close the cap.
Obviously this thing would be very fragile and only last a few days. The way I look at it is my platypus will eventually break on my thru hike anyway, so I'll just keep making these little puppies as necessary on trail and treat them carefully. I don't really plan to carry water as much as possible so my water storage solution might as well weigh next to nothing.

