20 Minute Tyvek Bivy

I got a bunch of Tyvek from Williams a couple of months ago with some sort of project in mind, and then was lurking around the recent discussions about bivy-sacks, and something started to come together in my head...

I'm going skiing and shooting today, but it's still too cold (it's warmed up to -9 at 10am...straight-up cold, figuring in windchill is for boastful sissies), so I got out my stuff and put together what I think will be a kick-ass bivy in 20 minutes (although it has to finish drying-curing...it took me longer to take/crop pics, and do this write-up than to make the bivy, but I figured that I'd share, and I'm having a 2nd cup of coffee down by the woodstove while I do this, so it's all good...




The Tyvek came in a piece 9 feet wide by about a gazillion feet long...I cut off a piece about 9 feet long...I folded the Tyvek in half, so the basic shape is about 9 feet by 4.5 feet (before I started to do anything else)...




I used scissors, silicone adhesive/sealant, and a glue-gun...this size silicone worked out to be exactly the right amount to seal the bivy...I chose silicone sealant because it bonds to almost everything and stays flexible (which will be nice when folding/stuffing this thing for use)...




I started out by sealing a simple straight-line bead along the bottom of the bivy, folding over about 2 inches...




After making an initial seal along the bottom, I followed this up with a zigzag bead of silicone, and folded the bottom another 2 inches up or so...

{{{Yes, I know, vacuum...we heat with wood, and have 3 cats and a dog}}}




After I had pressed the double-seam along with the bottom with a hardcover book to squeegee the silicone to insure good contact and a good seal, I repeated the above steps with the open side of the bivy...simple seam and fold, and zigzag seam and fold...




The final product is a bivy that should be light and waterproof, is open at the top (I lacked both the technical savvy and any ideas, so I'll just take advantage of the depth of the bag and snuggle down into it), has double-sealed seams, and ended up being 51" X 104"...

It occurred to me while looking at it that given that I sealed all writing and markings inside the bag (not by design, that's just how it worked out), it could be pretty effective winter camouflage for gear or me or both...

It will also be useful as an extra layer to wrap around my sleeping bag to keep condensation off of it when winter camping...

I'll inspect it once everything dries/cures, and then test it in the near future...comments, insults, ideas, etc. will, of course, be welcome...