So I burned a little creative energy this weekend.
I was shopping around for a ground cloth. I’ve always used a raggedy old piece of tarp. This faithful ol’ piece of plastic got me through several month-long Spectrum courses, (North Carolina, Arkansas, Texas, Ontario, and more) as well as a number of off-the-clock adventures.
Trouble is, I want to go lighter. I’ve seen the SilNylon stuff & can’t help a little gear envy.
Tyvek! The idea came to me while I was at a home remodel site.Turns out our local hardware store sells it by the foot. I’m not the first guy to think of it; not by a long shot. They sell it to PCT through-hikers all the time for ground cloths.
Excited about the “find,” I read some data sheets on it and got to thinking… the stuff is really strong, fairly lightweight, somewhat breathable (lets water vapor through but not drops) and relatively cheap. I seem to have lost my poncho/tarp (which is a pain to use anyhow) so I decided to make a bivy!
First, I started with 12′ x 3′ of Tyvek Home Wrap.
I washed it 4 times in the washing machine, cold water, no soap. This softened it up quite a bit & made it much less noisy. Don’t know if it hurts the waterproof-ness of it though?
Next, I laid a very basic floorplan out with a sharpie marker & made the cuts. My mom’s visiting right now & she gave me a few pointers on the sewing machine. (I’d balled it up the other day modifying a Jandd frame bag).
then the special Tyvek tape… this should seal the seams well.
Then a bit of Velcro. I put it on about 30% of the right side- trouble is, my 40 degree bag is LH zip, but the 20 is RH. This was an oversight, as I’ll probably use it more with the 40… Anyhow, I taped the edges for extra strength before sewing the Velcro in. I flapped the top side over so it can allow water to pass by.
And, voila! I have a lightweight, home made bivy. It cost me about $15 for everything. (velcro was USAF surplus 😉 )
It weighs 250 grams, or just over a half pound. Not too shabby. Combined with my 40 degree bag the total weight will be around 1.75 lbs and pretty darned versatile. If it works fairly well I might even keep it around for a while. I’ll have to report back later on that one.