Hi! Been offline too for a while...
Quote:I have so many questions, but the first is - how do you manage to get a seal with your 'head out' set up? π€
Well, it is qute simple - just a round hole that your neck fits in, not too tight. One trick is to glue (or sewing works too) the zipper in a form that it is dangling from the edge of the hole. I bougt the zipper by meters, and simply let 10cm extra of it on the neck side. That way it will not tend to unzip under strain.
With vacuum, it tends to stick to the skin and seal itself. If you try to jerk your head, some air will get in, but the plastic will fold and seal itself again, this time better π
The zipper itself is the biggest leak. I sealed it somewhat by sticking a strip of plastic from outside, on one side of zipper, covering it. When flat, it will be sucked to zipper and sealed.
A common vacuum cleaner will outrun the leaks and seal you tight. Any temporal leak will be sucked out by the mattress acting as "air spring" π
For starters, you can build the bag and try to vacuum wrap only the mattress, and cut the hole later when this worked.
Cheers!