I want to make a sleeping mat cover for my Thermarest mat which will incorporate a zipper so that I can zip on a waterproof cover when there is risk of condensation dripping off the tent down onto the bag.
Just wondering what material would be comfortable to sleep on, but have enough strength to have a zip sewn onto it without it ripping / tearing when put under tension.
Why not just sleep in a bivi bag?
^this^
Why not just sleep in a bivi bag?
A bivi is too heavy. I am trying to come up with a sleeping system where I have a lightweight zippable outer shell and quilted blankets inside the outer cover.
My motivation is that I move around a lot when I sleep and find mummy bags far too constraining. If I just open the bags and use them as quilts I find the bags spread out and then touch the inner fly sheet. This then means the bags get damp.
If I make the outer cover a decent spacious size it will hopefully provide enough room to make it not feel constraining.
You're making life really hard for yourself!
Get one of the Goretex bags and use that - no poles, etc so no weight.
I don't like mummy bags either, so I just use a rectangular bag and put up with the size and weight penalty. That would seem a lot easier to me.
Get one of these http://www.backpackinglight.co.uk/shelter-accessories/WB107.html fold it in two and sew up the edges. You can buy Tyvek from builder's merchants so if the sizing of the above is wrong you can make one yourself.
I've just got an Alpkit Hunka XL since a standard bivvy bag is a bit small to get mat, quilt, sleeping bag [b]and[/b] me inside. The quilt is used as a bag warmer to extend the useful range of the two season bag before you ask.