I've been wondering how to keep warmer using my supershelter while giving up the thickness of the open cell foam. I tried sewing a space blanket/fleece liner which kept me warmer when placed on top of the foam but it was louder than I'd like.
Then I saw a post by ZDP-189 suggesting a Balloon Bed in a thread on where to place a space blanket. I went to balloonbed.com and thought the idea looked like a nice way to provide an air trap under my Hennessy ULB. The company doesn't seem set up to handle orders from the States, so I started thinking about making my own. But since it would be for my hammock things changed.
Rather than the simple sewn through channels they use I wanted baffles for more coverage--especially since it would work better if going to ground. I found that it was easier to simply make loops. It required no more fabric and less sewing.
I considered the Insul-Bright Fabric from another thread but after looking at the fabric at Joann's I wasn't interested. The film layer readily shreds at the cut edges and I didn't think I'd need the insulation layer since that is the purpose of the balloons. Instead I made the top piece from half of an Adventure Medical Kits Thermo-Lite Bivvy bag I got at a used gear sale at REI. I've been using a bivvy as my sleeping bag in cool temperatures and it works nicely. The balloon channels are ripstop nylon. I shaped the top layer from two pieces using the open cell foam of my SS as a guide. The balloon channels are sewn to match the foam outline.
The bed takes 24 balloons which I pump up with a balloon pump from a Scholastic book/balloon set (How to make balloon dinosaurs). It was smaller than the other pumps at the party/toy store. It takes about 15-20 min to inflate them all. Wrapping my hand around the balloon to keep a tie off area wasn't too comfortable since I keep my nails a little long. Instead I took one of those super wide straws used for asian tapioca ball tea drinks and doubled it. Putting a length of straw over the end of the balloon and then the balloon on the pump means easy hands off pumping and a leaves a simple twist point for sealing the end.
The balloon bed site has people tying off the balloons and popping them in the morning. They only use 7 balloons. Even so I don't like the idea of throwing out balloons each day (especially 24 a night). I looked online for some kind of clip for balloons and found both a clip and a disc. Neither were available locally so I cut up a gallon milk jug to make quarter sized discs. They work great. Most of the balloons I pumped up at the start of a week were still inflated a week later. Lying on the balloon mattress doesn't pop the discs off either. Simply twist the balloon and run the twisted portion around the two slots in the disc a few times and it is secured. The discs can be seen in this picture where I was confirming the channel size for the balloons.
So far the bed is unfinished. I want to try using it before cutting off any of the excess fabric. I might like the extra wind protection or perhaps I can skip slipping it into the super shelter by making it a shelter layer by itself. I haven't had a chance to test it yet but I look forward to trying it out.
For a second round I'd really like to give up the balloons. I've got some Sea to Summit Ultra-Sil Dry Sacks. They hold air nicely. An air bed made with Ultra-Sil that you simply roll closed would be a nice layer under a hammock. Unless going to ground the fabric doesn't need to be super strong, nor does the seal to hold in air. Since the length would always be the same you could have a pair of clips after three rolls at the end and a few in the middle to secure it. Although if the open end was near the feet perhaps the side clips would be enough.