As I’ve noted before, becoming a light-weight hiker can be a rather expensive process (and a lengthy one if you want something from MLD). I am on a budget and a schedule, so I’ve had to be a bit creative.
After looking at a variety UL bivies to go with my Locus Gear tarp, both Jototaro (of Locus Gear fame) and Hendrik encouraged me to try making my own out of tyvek (don’t know what tyvek is? here’s a short primer). Unfortunately, I have never done well in arts and crafts, I can’t really draw or cut straight, and I haven’t made anything out of fabric since I made a pencil case in 8th grade home-ec.
But, I did some research and manned up. Part of the whole experience of hiking across the alps is trying something new, pushing my comfort zone: trusting a bivy I made with my own uncertain hands certainly qualifies as challenging my comfort zone.
Here is advice for new light-weight hikers: when in doubt, consult the Backpacking Light forums. Once I did that, things started to roll.
This excellent BL thread convinced me I was capable of making a bivy and, since I don’t have a sewing machine, to use 3M Super 77 spray-adhesive. So I picked some up at Tokyu Hands. As for Tyvek, Locus Gear’s sister shop Outdoor Material Mart sells all sorts of MYOG supplies including a tyvek not normally seen in MYOG projects in the US.
The tyvek they sell is 1446B, a UV blocking soft-type tyvek. It’s water resistant to 14.9 kpa (I don’t know the conversion, but 9.6 kpa is 1000mm hydrostatic head, which considered waterproof according to my research), soft and very lightweight at 47g per square meter.
I didn’t have a pattern, and decided to make it up as I went along (kind of my MO). First, I got some paper clips and made some mock up bivies to give me a sense of how different designs would play out. After I had a decent idea, I drew out a tapering design top and bottom on two pieces of tyvek, leaving 10cm on each side for a nice fat seam. The plan was for something that resembled a MSR e-bivy without a side entry. I screwed up the first side, but busting out some trigonometry (cosine!!) managed to get long straight lines from my short straightedge on the back side. Now I have some sweet marker lines on the outside of my bivy. Not quite FSTPKR’s trail flare, but it will do.
Next: Cut out the pieces, and glued the body section to the bottom with no problem at all. The seams are lined up so that stress from rolling etc will pull in line with the bond (just overlapped the edges of the top and bottom). For the corners at the foot end, I cut the corners and folded them in to get a smooth seam (think wrapping a present). Lucky, the Super 77 is pretty forgiving so I could mash it together a bit just fine. I did the same for the hood. The whole thing took 3-4 hours including thinking, correcting errors, more thinking, and letting the glue dry. I think the next one will clock in at less than 2.
I stood in the shower with the bivy, worked out perfectly, dry as a bone. I’m going to trail test the bivy this weekend, and if it works (ie doesn’t tear and does breath) and there is interest, I’ll post photos and more specific directions. If it’s a disaster, I’ll post those photos and warn everyone away from it.
Do you care how much it weighs?
Thought you did. Less than 6oz. (5.8-ish). Yes sir.
The One Big Caveat:
For information on the effectiveness of gluing tyvek, this report is a must read. The conclusions, which proved true for me, is that a bonded tyvek seam is stronger than the fabric itself. However, the bond will delaminate very easily. So, if you bond the tyvek in a way that the pieces can be pealed away from each other, they will (think the motion of opening a book, stress coming perpendicular to the top edge of a bond).
In my current version of the bivy, the hood overlaps the chest section leaving a flap that will delaminate quit easily. In order to remedy this, I will either have to cut the flap OR sew a couple of stitches at this stress point to take the stress off the glue. I am planning on doing the ltater.
All the other seams, as long as there aren’t any flapping edges, appear to be very strong.
One thing I will do differently next time:
I made the hood far too long and the chest piece too short. I guess I thought I was big headed (har….). So I’ll probably glue on a flap to extend the non-hooded coverage up to my chin.
Conclusion:
A bonded tyvek bivy is an easy and fun DiY project. It seems like it will work well, and I’ll be super stoked to sleep in something I made myself. I’ve got a bit more tyvek so I might try to make another more shapely bivy, and if I can find a sewing machine on the cheap I will definitely be adding no-seem-um mesh and a side zipper.
Also thinking about making some tyvek chaps ala GG Spinn-chaps with the scraps…
If your thinking about buying a bivy, why not take an evening and try making your own first?
Do you make your own gear? Why or why not? Do you trust the stuff you make?
Is it Ironic that the Internet is Where I Learned how to Hike?
I’m used to being a bit of a freak show. Or maybe I flatter myself. But, I have two strange names, I’m a bit short, and I have a wee pot belly. It’s covered in hair. And backpacking, it was always something I did away from my day-to-day life (except for with my Lady Friend who I co-opted by buying her nothing but backing gear for birthdays, anniversaries, etc).
So when I decided that it was probably a good idea to walk across Japan (the short way), it was greeted with a sputtering of syllables amounting too ‘yes, you have just confirmed you are a bit strange, and I’m not quite sure you will do it.’ Of course, it was more politely said, and they probably didn’t mean that, but it’s what I heard given that I felt different.
The internet is magic. As soon as I unilaterally declared myself in, or opted in, or joined the online light weight hiking community, I met people who found what I was hoping to do exciting, normal and not remarkably difficult. I appreciate this deeply.
And answers to questions! The advice and response time of the lightweight hiking community is unmatched. Not knowing how to do something is no longer an excuse for not doing something.
Sometimes the Lady Friend gives me shit about twitter. And that’s healthy, it is addicting. But in the last month I have talked to more interesting people, learned more, and felt more inspired than for a very long time (follow me on twitter!). Walking across Japan (the short way) went from being a fantasy that confirmed I was a ‘different kind of person’ to a possible, challenging, and fun reality.
The Church gets that bit right, community is powerful norm creating force.
In May 2009, I had never participated in an online community outside of facebook (stalking). Lucky, that changed. Even after just a month, it has been incredibly motivating.
Warm-up Question: What are your favorite blogs, hiking related or not?
Advanced Question: Did I misuse irony in the title?
Questions for the audience:
For all who participate, blog, comment, etc: What’s in it for you? Why do you value this online community? Why do you share your stories, time and effort?
For all reading this blog who haven’t commented and don’t usually comment on blogs: please start. Join the conversation, contribute your ideas, ask questions, get inspired. After a month of blogging I’ve cracked 1000 page views, but only have comments from 6 different people; I’m really curious who all of you are. Tell me. Right now. It’ll be fun.