After an overnight trip to the woods last year, I found a hole in my synthetic bivy bag caused by a spark from a fire. I knew that if I kept sleeping next to a fire with that bag, it would end up looking like Swiss cheese! In addition to this problem, I didn’t like how this synthetic bivy retains moisture. I had to come up with a better solution for sleeping close to a fire during the cold part of the year.
After some head scratching, I came up with the wool-blanket bivy. I sewed a lightweight wool blanket (1.2 kg/2.6 lbs.) into a bag and then added three buttons and button holes. This wool-blanket bivy bag has a few advantages:
– Allows moisture to escape from the sleeping bag inside.
– Protects synthetic sleeping bag from sparks.
– Adds some warmth to the sleeping bag.
And here it is with my sleeping bag inside:
The synthetic bivy I had been using weighs about 0.6 kg/1.25 lbs., so by swapping it out for the wool bivy, I’m really only adding about 0.6 kg/1.25 lbs. to my overall setup, but getting a lot of functionality in return. By the way, I tested the material for fire-retardant-ness with a ferrocerium rod before starting on this project and was happy to see that the sparks barely had an effect.
Here’s a pic from a different angle showing how it looks on my ground sheet, which prevents the wool bivy bag from absorbing moisture from the ground.
For warm-weather trips, I still use my synthetic bag (with the zipper unzipped) because I don’t need the extra warmth and fire protection, but for chilly nights next to a fire, this wool-blanket bag does the trick!
P.S. – The Woodswife suggested that this wool bivy could be used by itself (without a sleeping bag) if only minimal warmth is needed, e.g. on warmer summer nights. Good thinking! EDIT: Ron from The Trying Woodsman pointed out that this arrangement wouldn’t be very mosquito-proof. If an outer bivy isn’t used with the wool-blanket bivy, I’d have to agree!
P.P.S. – Obviously, this bivy is not meant to keep out water, either from above or below, but since it is not usually used in wet weather, this isn’t an issue.