I was wondering if I could make a bivy with a Gossamer Gear polychro groundsheet bottom sewn or bonded to a Momentum top and hood. The polychro would be lighter and less expensive than a silnylon floor, easily repaired with tape, and (when needed) replaceable. Anyone tried this? Am I crazy? I have been very impressed with how durable the seemingly fragile polychro really is (when used a groundsheet). Because it is a shrink-wrap type plastic, it seems to stretch rather than puncture.
