DIY Tyvek Bivy kit....any interest?

[fastmtnbiker33w]

I'm in need of another bivy....my last one got pared down to a ground cloth during AZT.  I plan on making something like the one showed in this link...

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=46661

However, my design would not use that exposed zipper.  It would incorporate a storm flapped zipper and I'm thinking either #3 or #4 coil zipper with double pull....still waiting on a quote from my supplier.  The zipper would be stitched in with a small mosquito netting under the main top flap.  I want to make mine very roomy and easy to get in and out of.  I'm 6'5" with size 15 feet and tend to sleep kind of sprawled out on my pad.  I've yet to find a bivy stock model out there that I like....nothing fits around my feet.

Since I can get stuff so freakin' cheap, I thought I'd see if there would be any interest here in the purchase of a kit of some sort.  It would include a specific amount of netting (maybe half a yard?), a long length of zipper (3 yards?), a roll of 1" carpet tape (that stuff totally kicks ass with Tyvek), 4 sliders and my orange and reflective paracord pulls, and  Tyvek (either 5 yards of the 3' wide or 2.5 yards of the 9' wide roll....which would give you more to work with with the possibility of fewer seams).  You could come up with your own pattern, copy mine or some other one like the one shown in the link above, or have me partially assemble it for you and you could tape up the bottom custom for your size.  My old one....which was very crude....was right at a pound and very large.

I'm pricing things out at around $30 each for materials and maybe shipping.  If anyone is interested or has any questions, let me know.  I'd like to order everything sometime next week as I need to have a new one before my Christmas break.

[metalartgate]

I'm interested!

Gary

[chrisx]

Please note
tyvek is not water proof.  
I used a piece of tyvek for a ground cloth under my tent for a few years.  When the rains came, I mean the real rains, I learned the hard way.  Water seeps through tyvek when the ground is saturated, and up into the tent.  last year I used a very thin sheet of plastic as a ground cloth.  It did not seep when the rains came.  This year I am using a plastic laundry bag with a hole cut, so It has a second use as a poncho.
Also consider,
The chemicals tyvek is coated wiht were never meant to come into prolonged contact  with the skin.  

[fastmtnbiker33w]

Thanks Chrisx.  I've spent more than a few hours reading through the backpackinglight.com forum and haven't read anything in regards to either of your issues.  I'm guessing most would prefer to sleep where the ground is not saturated.  That's not to hard for guys like me in the Southwest.  I'm skeptical about the chemicals as I've never seen any OSHA info regarding Tyvek.  It is used in lots of different clothing applications.  If you have some links on that, please post.

So far the interest is only meager.  It's looking liking this is going to be a small purchase for myself as I'd need 20 people to make this worth my time and upfront expenditure.  I may blow my savings and get a bunch of cuben fiber instead.....breathable for the top of my bivy.

[fastmtnbiker33w]

I found the MSDS (Material Safety Data Sheet).  Anyone who had a decent science teacher should know about these.  They are easy to understand.  No such worries about chemical coatings.  There aren't any coatings.  I'll be happy to email the pdf.

You can go here and type "Tyvek" in the search window and find the MSDS. 

http://www.3eonline.com/EeeOnlinePortal/DesktopDefault.aspx?tabid=90

[Damnitman]

11. TOXICOLOGICAL INFORMATION- Inhalation-Improbable route of exposure.  Normally, converting presents no dust hazard from Tyvek (R) because it is composed of continuous fiber.
Ingestion-Improbable route of exposure.
Skin-Skin contact should produce no skin irritation, swelling or sensitization.
Eye-Physical mechanical irritation only.
Chronic Effects-None of the components present in this material at concentrations
equal to or greater than 0.1% are listed by IARC, NTP, OSHA or ACGIH
as a carcinogen.  http://www.3eonline.com/ImageServer/NewPdf/28265ecb-deea-4bb3-a238-05882d054c29/28265ecbdeea4bb3a23805882d054c29.pdf



...I really like your Idea, but have a different direction I would like to go with Bivy design...

[metalartgate]

Hey fastmtnbiker33w,
Rather than sewing in a zipper what do you think about using one of these? Tarpline USA Tarp Zip-Up, Black  search Amazon. question is will it stick to Tyvek.

-gary

[fastmtnbiker33w]

That would work very well.  Not sure how bulky it would be, but it appears to not be very heavy...only a couple of ounces (3.2 oz listed).  But it's pretty expensive.  I'm trying to spec this with enough zipper for 2 zippers (one long one for the main compartment and a shorter one for the bug netting) with 4 sliders and should be able to do that for around half that price.  A sewn on zipper can be reused when/if the tyvek finally wears out.  You will also be able to sew on storm flaps to cover the zipper allowing it to last longer and keep water out.

I'm getting quotes from more than one supplier.  So far, things are looking good.  I've already purchased tyvek.  I needed some for another project.

[metalartgate]

Sounds good. I am still interested in a group purchase if it happens.

[Eugenemtbing]

I am interested in an experimental bivy kit.  Any updates?

[fastmtnbiker33w]

I've got almost everything....still waiting on no-seeum netting which should be here by end of the week.

I'm going to do a $30 kit which will include shipping in the lower 48.  

Here's what it will include:
 - Tyvek 2.5 x 3 yards
 - 3 yards of #3 zipper
 - 2 double sided zipper pulls (black)
 - 2 single sided zipper pulls (silver)
 - 4 paracord zipper pulls (orange/reflective with plastic end clip)
 - 1 yard (54" wide) black no-seeum netting
 - 1 roll of double sided tape (enough to do 2....maybe 3 bags depending on your pattern)

If you want a greater or lesser quantity of any of these items, I'm sure we can work something out.

For an additional $15, I can send you sewn up zippers that you can tape into your bag.  I'll sew a storm flapped side and a non-storm flapped side with a really long stitch length to reduce tearing.  Tape it in, maybe use a needle and thread to stitch a slider stop, and you're good to go.

Below are some pics of sewn zippers.

[fastmtnbiker33w]

My final product....

7' long, 28" wide, 1 foot deep.  All exposed seams are taped.  Stitching around screen drape is there to help hold shape.  483 grams.  Double pull zipper for main compartment, single pull for screen drape.  Could save a couple grams by not using my larger pulls but I wanted something that was easy to grab.  Lots of reinforcement.

I could save a bunch of weight if I rounded the ends better.  Making it square is kind of janky, but I like the roominess.  That was main goal....roominess.  I'm a "sprawler" . 

[Eugenemtbing]

Fastmtbr33w, can you email me some pix of your setup and your address, then I'll mail you payment for a bivy kit. 

For some reason, I am not able to view some photos on bikepacking.net anymore.  Would like to see how your design worked out.

Thanks,
Joe

jkidd143 at gee mail dot com

[fastmtnbiker33w]

Bivy kits are ready to ship.  If you want more than one, let me know and I can discount it by only sending you one roll of tape.

[fastmtnbiker33w]

I got an email with some good questions that I figured I'd better post here.

How large is the bivy once made?  Depending on what pattern you use (your own or something you find on the internet) and depending on if/how you make a screen window, you should have plenty of room.  I made mine to be 7' long, 28" wide, and a foot tall.  PLENTY of room.  I'm 6'5" 200 lbs.  My size and desire for a roomy bivy were the main reasons for this project.

Is the bivy water proof? Yes....to a certain extent.  This depends on how old the material is.  New Tyvek is highly waterproof and less breathable.  As you use it, it gets softer, quieter, more breathable, less waterproof.  I've read that some people have had seepage through the bottom when on very wet ground.  An additional ground cloth might be needed if you camp on saturated ground a lot.

Will I need to set up a tarp in addition the bivy or is the bivy good enough as a stand alone shelter? I think this depends on what you're willing to deal with.  I've never used a tarp or tent for bikepacking.  I've never viewed a bivy as shelter.  It's something you seal yourself into and pass out for a few hours of sleep before waking and getting back on the bike.  I've been very lucky in that during heavy rainfall, I've always found alternative shelter or trees large enough to make resting in the bivy uneventful.  I guess the answer to this question is more related to your level of fear and resourcefulness.

How difficult is it to put the bivy together once I receive the materials? I must admit that at my size, working on the floor to do most of the assembly, is a pain in the...knees and back.  LOL.  It took me a day to figure out the pattern I wanted to use and I spent a very methodical 8 to 10 hours putting it together.  I wanted to use as few seams as possible, utilize as much material as possible, and make it convenient to get in and out.  Once you tape it together, it's done.  You can't untape it or you will rip the fabric.

Do I need a sewing machine or any special equipment to put it together?  You will want a ruler or tape measure, a square, and a good pair of scissors.  The zippers have to be sewn in.  I sewed the zippers to strips of fabric which I taped into my build so there would be no exposed stitching. This added maybe a couple of ounces at the most, but made it much easier to build.  I can provide you 9' of sewn up zipper with large storm flaps for an additional $15 fee.  If you get pre-sewn zippers from me, you will need a needle and thread to sew stops into the zippers to prevent loss of the zipper sliders.  I made 3"x3" fabric patches to put over the end sections of the zippers to provide a better water seal. 

If I choose to sew in my own zippers, how should I do it?  If you want to use a home machine to sew in your zippers, you will need Tex-45 thread and corresponding needle.  You can use Tex 69 or 70, but the holes will be bigger and you may not get your stitch length long enough compromising the strength of the fabric.  If your machine does a zig zag stitch, it would be advisable that you use that setting to increase the distance between the needle holes.  How you stitch the zippers to the bag is your decision.  I found it much easier to sew strips of fabric to the zippers, then taping them in.  This provides great water proofness and makes it much easier to assemble the bag.

[Racingguy04]

What do you think about sewing the whole thing? I've sewn a little of tyvek and I'm inclined to think that sewing might be more durable than tape. I'm thinking of sewing it together and then taping to seal the seams.

[fastmtnbiker33w]

Taping is WAY stronger.  No holes and almost impossible to undo without destroying the fabric.  Stitching then taping.....I just don't get it.  if you are taping with single sided seam seal tape, you'd just be adding weight and more time and energy.  I dont think you'd be adding strength. 

I spent two nights in mine this weekend.  First night was 28° F with a high dew point....seems I remember reading that the humidity was 41%.  My bag is a 30°down bag and I use a full length neoair pro.  I had to ventilate it because I got hot.  I was covered in frost in the morning and the inside had a bit of frost as well.  The next night was in the low 40's and raining buckets.I was under a shelter and I slept in the bivy without my sleeping bag.  I got misted all night.  About 7 hours.   The zippers were easy to operate and I had plenty of room.

[Luked77]

There is a product out there called Seam Grip made by McNett. I have used it to repair blown seams on waterproof panniers and drybags where the seams are welded and not stitched. Its super strong and designed for stitchless seams. its a little harder to work with than tape but it might provide better long term adhesion and sturdiness. Just a thought! I like your design and idea for the bivy!

[fastmtnbiker33w]

Bivy kits are being shipped.  Thanks to those who have purchased.  I have plenty more. 

[Eugenemtbing]

I'm getting 2 kits.  Was enlightening to look at the backpackinglight link and one that links from there.  Some cool pix of other earlier iterations of Tyvek bivies.  Thanks for setting this up for us, David!