- Jul 1, 2017 at 12:53 pm #3476573
See next postJul 1, 2017 at 12:53 pm #3476574
This project is my first foray into MYOG. The plan started out simple enough. I was going to make a basic tarp and envelope-style bivy with cheap materials to hone my sewing skills, then move on to a pack. Quickly though, my dives into the depths of these forums yielded inspiration for more complex modifications to the bivy design until eventually, this was the result:
All materials are from RipstopbytheRoll:
– 1.1 oz. (1.3 finished) silpoly XL seconds for the bottom
– 1.0 oz. HyperD for the top
– 0.9 oz. noseeum mesh
– 3/8 in. grosgrain
– 1.5mm drawcord
– Gutermann Mara 70 (used with a size 14 needle I already had)
– #3 zipper with double sided slider
– total cost was $57 which included material for making a tarp
– 3D half-moon footbox
– 3D triangular headbox for wind shedding
– Long center zip
– 84″ long (~74″ usable due to the triangular head area)
– 70″ wide at the shoulders, tapering to about 50″ in the legs
– footbox circumference is roughly 56″
– grosgrain tieout is attached to HyperD, not mesh
– 5.5 oz.
I based some of the design off of Lance M’s bivy project, particularly the center mesh. Only once I had started sewing did I learn of the new EE Recon bivy which is probably the closest comparison. Construction was very difficult, which is why it took about three weeks. I probably made every newbie sewing error out there, but none of the errors affected its functionality, given that bivies are low-stress items. With the exception of one French seam, all seams were flat felled, though the second stitch sometimes went through three layers of fabric and other times through four depending on where the seam was (I didn’t assemble the bivy in the most logical order so I had to be creative at times to get the fabric into the sewing machine).
Overall, with one major exception, I’m really happy with how it came out. Unfortunately, the excellent weight came at the cost of interior space. Mistakes and large seam allowances shrunk the dimensions. I’m 5’11” 150lbs and with an Exped Airmat Hyperlight (2.5″ inches high, I believe) and a 32 degree mummy bag, the bivy was too tight for me to fit. With a Ridgerest and a 32 degree bag, however, I was able to fit, snugly, but comfortably. I suspect that this bivy would be ideal for someone under 5’10” who uses a CCF pad and a 30+ degree quilt. If anyone is interested, I’ll be posting this on Gear Swap shortly.
Next up is version 2.0 with a 10d top fabric, 0.7 oz. noseeum, and larger dimensions
(I’m also almost finished with a tarp, but it’s pretty boring. Tapered, about 9′ long, 5’8″ wide at head, 4.5′ at foot, no ridgeline because the silpoly is 70″ wide. I might post some pictures tomorrow when it’s finished)
That was my first stitch. Luckily, it’s well hidden within the seam :)
Jul 1, 2017 at 8:26 pm #3476633
Basalt GearBPL Member
@basaltLocale: Missouri USA
Spencer, this is great! Thank you for posting this. I’m beginning a bit behind you in both sewing skills and development of design, but like you, I recently saw and got interested in the EE Recon bivy. When the time comes please post any materials and pattern info you are willing to share. I’m definitely going to adopting most of your design based on what you have posted here. KeithJul 5, 2017 at 3:07 pm #3477118
Andrea CBPL Member
I’m not a great fan of Bivy bags, but I’ve some good Silnylon that I can make a use of.
This post was a good inspiration, some good work done up there :-)Jul 26, 2017 at 2:03 pm #3481316
I finished my second bivy. This one has a similar design to the first but several small changes make it far more functional. I’m very happy with the finished product.
Pictures are here: http://imgur.com/a/u6WHv
Materials are the same as the first, with the exception of using Membrane 10 instead of HyperD and 0.7 oz. mesh instead of 0.9 oz. Unfortunately, I don’t have access to a scale until next week, but I would guess that it weighs 5.5-5.8 oz.
Realizing the inefficiency of a triangular-shaped head box, I went with a curved design on this one as well as a higher cone, about 15″. The effect is that the whole length of the bivy is usable and more spacious. The other major change is that the dimensions are larger. 85″ long, 62″ girth at the narrowest point near the feet, increasing to about 65″ where the large mesh area begins. At its widest point, where the headbox begins, the girth is 79″. The half-moon footbox is about 58″ in girth. I don’t have my gear with me at the moment, but it should fit similarly to a Borah Gear bivy with more space towards the shoulders. Other small changes include small tieout loops, one at the head and two at the feet, to stake out the bivy to stop it from sliding and more substantial zipper stops made out of small patches of fabric.
My sewing skills are by no means professional level, but I think they are functional enough that I’m ready to tackle a backpack.Jul 26, 2017 at 2:31 pm #3481318
Jerry AdamsBPL Member
@retiredjerryLocale: Oregon and Washington
I like how you’re proud of the non functional affecting screw-ups : )
I’m working on a hybrid bivy/quilt. I think it’s been 6 months so far. I have to buckle down and finish that some time. I have a perfectly good one already, the main thing is to increase the loft a little, add more down, to make it a little warmer. Maybe I’ll finish it by next winterAug 17, 2017 at 5:41 pm #3485705
Larin MBPL Member
Have you posted the first version on gear swap already… I might be interested.Aug 17, 2017 at 10:07 pm #3485755
Larin, I sent you a PMSep 5, 2017 at 10:16 pm #3489266
Here’s the final bivy of the summer : Pictures
- 0.93 Membrane silpoly bathtub floor, NS50 0.5 oz. mesh top
- Total weight: 4.2 oz.
- 74″ long, 28″ tapering to 21″ wide
The 0.5oz. mesh was a little hard to work with – so fine that chalk marks barely showed up and so stretchy that it was difficult to cut – but I would recommend it nonetheless. The strength to weight is incredible and, for what it’s worth, I love the way it billows in the wind.
Sep 6, 2017 at 10:39 am #3489351
- This reply was modified 2 weeks ago by Spencer A.
Lester MooreBPL Member
@satoriLocale: Olympic Peninsula, WA
Spencer – the simplicity, function and quality of your bivys (and their low weight) are inspiring me to buy a sewing machine! I’ve been itching to build a sub 7 ounce inner net tent for my Deschutes CF tarp out of the same bathtub and netting materials that you’re using. It’s helpful to hear your MYOG experience with the NS50 netting – that’s helpful info for net tent designing purposes.Sep 6, 2017 at 7:43 pm #3489504
Go for it! A bivy or net tent is a great first project because you have to do long flat felled seams with slippery fabrics. Bivys are also more forgiving than most other projects because there’s little stress on any one component. And I enjoy the simple trig and geometry that goes into making 3d head boxes; besides, its been helpful for planning my prototype shelter that has a lot of funky angles.
Let me know if you have any questions about the materials or design. I’m happy to help
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