Since she won't be using it for hiking (yet
) I wasn't super critical of the weight but didn't want it to get out of hand either. I think I stuck a pretty good balance between weight, price, and warmth. I used 1.9 oz ripstop nylon for the shell and liner, 2.5 oz Climashield Apex on the bottom and in the hood, 5 oz Climashield Apex on top and also put another layer of 2.5 oz Apex in the lower 1.5' of the top over the foot area. I decided, for simplicity's sake, to just make the bag rectangular. I could have saved a few ounces that way but Becca doesn't like how constricting a mummy bag feels either, so I left it untapered. The zipper is a very lightweight #3 coil zipper. Looking back I would have got something a little more substantial but we'll see how it holds up. The zipper runs almost all the way down to the corner so you can open the bag wide and get in easily. I also added an anchored cord lock and fabric sleeve for a draw cord around the hood but overestimated how much extra I had and will have to buy some more to add later.
As I mentioned, the zipper is the part that had me worried but once I figured out the zipper foot on the sewing machine it was a breeze. What I did was separate the two sides of the zipper, pinned them to the black liner fabric (carefully lining them up so they would match again) and sewed it in place. Then I laid the green shell fabric on top, right sides together with the zipper sandwiched in between, and sewed around the whole perimeter of the bag, leaving the foot end open to stuff the insulation in. I chose not to stabilize the insulation because it was a pain to run through the sewing machine and that's the one choice I think could come back to bite me in the project. I'm surprised at how good the zipper looks, there's one little spot where the shell fabric got a little wonky but since I sewed the zipper to the liner first you can hardly tell. And now the specs:
33" wide x 82" long (from the top of the hood)
It packs into an 9" x 18" stuff sack.
And it weighs 2 lbs 4 oz!
According to the calculations I found for synthetic insulation it should be good to 30*F but if it keeps Becca warm down to 40* it will be sufficient. Much colder than that and she's questioning my sanity when I suggest we sleep outside.
Cost of materials was a little over $100.
Teaser pic:And a few more pictures on Flickr.
Thanks for looking!