My wool-blanket bivy – A “blast from the past” post

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.

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10 comments on “My wool-blanket bivy – A “blast from the past” post

  1. American Grouch says:

    Interesting, I’ve been contemplating doing something similar.

    Right now for warm weather use I’ve got a wobbie mated to a very light weight 5×7 70D nylon tarp, the MEST to be exact.

    This is waterproof, light weight and makes for a small bedroll. It’s warm enough for 50F and up, could get by between 32F and 50F with the addition of some natural insulation but below that I’ve got to go heavier. Adding a good wool blanket to that combination might be the ticket to get me down to just above winter bag weights.

    I really dislike carrying the big bulky winter bags and typically save that for pulk travel. I think I’m going to try your idea out, that’s a good one!

    • Wobbie? Is that anything like a Wookie? 😉

      Glad to hear you like the idea! I bet adding a wool bivy, and maybe even a fleece sleeping bag liner, too, would solve your problem. Both those additions wouldn’t take up a lot of space (and all three not nearly as much as a winter bag), but they’d be good down to 32*F for sure.

      Thanks for the comments!

  2. OZme says:

    getting good bivy is next on my list. goretex should be good one, but I have some distrust over that material and is getting stronger… so this blancket bivy is something I should try out some point. if can add some level of water repelling capability, then would be perfect.

    • Yeah, the downside of this bivy is that it’s not water-repellant, but since it’s mostly a fall/winter item, it doesn’t really bother me too much. I have an idea for an “all weather” bivy, where I would attach a covering of wool or canvas just to the top of a synthetic bivy bag. This would make the bivy bag waterproof AND fire-resistant. 🙂

  3. Ron says:

    Nice!
    Add a tightly woven canvas outershell and you’re good to go!
    It’d be more breathable, eliminate small debris getting caught in the wool and stinging you at 02:30AM and mosquitos can’t get to you (which they still can through the losely woven wool), thus eliminating more stinging…
    Another advantage is that, if this combo should get damp/wet, you can easily disassemble it and hang it out to dry, opened up.

    • Yep, canvas would work as well. In fact, if it were waxed etc. canvas, it would be both water-resistant and fire-resistant. 🙂

      Luckily, breathability isn’t really an issue with this wool bivy. It allows plenty of moisture to escape, which is one reason I like to use it. As for stuff getting stuck in the wool and mosquitoes, you’re right, canvas would be better! However, since I only use this bivy in cold weather, there aren’t any mosquitoes to deal with (EDIT: Oops! I did mention the possibility of using it in the summer as a light sleeping bag. Sorry Ron!). 🙂 I also always put it on a ground sheet, which keeps dirt away.

      On the whole, though, I agree with you that canvas would be a very good alternative! Good thinking, Ron. 🙂

  4. Ron says:

    Forget about the waxing!
    I was advised against it on the wintertrekkingforum, where it was said that waxing inhibited the breathing, causing moisture to get trapped inside. And we all know how that feels, when it gets colder.
    Also the waxing might make you cover more flammable! Not a got thing to have, when lying next to the fire and adding fresh pinewood to it…..

    • Good points! I think the thing to take away from this is that there probably isn’t a perfect solution. If you want a certain feature, there’s a good chance you’ll have to dispense with something else.

  5. OutdoorEnvy says:

    Great idea and very simple. You can get plenty of cheaper end wool surplus blankets so this wouldn’t even cost much to do. Nice post, I’m going to give this a try this coming winter.

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