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World's Lightest Rainjacket/VBL
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Dan Durston
(dandydan) - F

World's Lightest Rainjacket/VBL on 10/19/2010 17:58:46 MDT Print View

Inspired by Benders 2.3oz cuben rain jkt, I whipped up this CT2K.08 rain jacket/VBL (vapor barrier layer) the other day.

Cuben VBLa

44g! Yup 1.55oz!
EDIT: 42g / 1.49oz now that I used lighter shockcord in the wrists.

The purpose of this jkt isn't to replace my regular 6.2oz Marmot Essence rain jacket, but rather it's:

1) To carry on trips where the forecast looks reasonable but I don't want to take a chance of not bringing any rain gear.

2) To use as a VBL on winter trips.

I designed it as a pullover partly because it's lighter and partly because my sewing machine is busted so I couldn't sew in a zipper. There's not a stitch in this garment.

I opted to make it hoodless because that's easier and because I'm a fan of using a brimmed hat rather than a hood in the rain as it's less clammy and easier to hear.

The only 'features' on this jacket are shockcord in the wrists (non adjustable) and a bit of shockcord in the waist. I needed to make the torso a bit baggy since it's a pull over so I added two short bits of 1/16" shockcord to snug up the waist.

This jacket was extremely simple to make. I laid my windshirt shirt on the floor, laid cuben over top and traced the outline with a dry erase marker. I repeated this to get the two halves of the jacket. You'll notice a few more seams on mine (okay a lot more, one half was made from 7 smaller pieces) because I only had scraps of cuben on hand so I had to bond multiple pieces together to get a piece big enough to trace the windshirt onto.

I made it a bit wider in the torso than the windshirt since it's a pull over and to allow room for overlap when the two halves get bonded. I also made the sleeves and torso a bit longer since I can always shorten those later when I finish the edges.

I bonded the two halves together with SeamGrip. SeamGrip isn't the greatest stuff but it works okay. I wouldn't build a tent with it. I remains a little sticky even when dry so you need to dust the seams with something to prevent the jacket sticking to itself. I was out of climbing chalk so I used baking soda. It seemed to work good.

Next I finished the wrists by putting it on, seeing how long I want them and then folding in the cuben to finish the edge. As the pictures show, I put a little shockcord loop in with a small hole. Once the wrist was dry I pulled the shockcord tighter and tied a knot so get the desired tension on the wrist opening.

Lastly I finished the bottom hem and neck area. I left it a little longer in the back. I used a few smaller pieces to build it up around the neck a bit to fit better and I used some thin strips to cover the raw edges to prevent tears. I will add a flap over the slit in the neck eventually when I get a snap to secure it. This will improve it's performance as a VBL.

Cuben VBLc

Neck area:
Cuben VBLb

Waist shockcord closeup:
Cuben VBLd

Cuben VBLg

Back - I left a little extra length back here to keep me covered when I bend over.
Cuben VBLf

Edited by dandydan on 10/19/2010 22:36:43 MDT.

Dave -
(FamilyGuy) - F

Locale: Up there
World's Lightest Rainjacket/VBL on 10/19/2010 18:05:40 MDT Print View

Pretty amazing. You should start selling these.

What kind of HH and tear strength do you get from the fabric?

Dan Durston
(dandydan) - F

HH & Tear on 10/19/2010 18:19:05 MDT Print View

Tear strength is pretty darn high with CT2K.08 cuben (0.74oz). I can't start a tear at a raw edge by hand and even an existing tear is very difficult to enlarge. Tear strength is way higher than silnylon.

By HH I imagine you mean hydrostatic head. Being essentially plastic, I imagine the hydrostatic head is virtually infinite when the jacket is new. It shouldn't leak until the water pressure physically cuts a hole in the material. Of course this means there's zero breathability too. Over time abrasion can create un-see-able pinholes in the materials. Some of my older cuben stuff sacks will drip water through if I fill them up with several liters of water. Even at this state, I don't think rain would penetrate the material....maybe it would slowly soak through the seat of rain pants if someone was sitting down.

RBH Designs sells something similar. It's got a full zip so it's 2.5oz and $195. I'm sure they do a nicer job building it as I slapped mine together in no time. RBH will also add a hood ($60), pit zips ($32) and forearm zips ($14) which would probably get you close to 4oz.

Edited by dandydan on 10/19/2010 18:28:57 MDT.

Chris Peichel

Locale: Eureka
rainjacket on 10/19/2010 19:06:58 MDT Print View

That's sweet. Simple is very very good.

/A .
(biointegra) - MLife

Locale: Puget Sound
Re: rainjacket on 10/19/2010 19:28:57 MDT Print View


Thus there should be no reason a sub 1 oz. pullover is not possible with .33 Cuben.

Dan Durston
(dandydan) - F

42g on 10/19/2010 19:53:02 MDT Print View

I just replaced the 3/32" shockcord in the wrists with 1/16" stuff and shaved off 2g so it's tipping the scales at 42g or 1.49oz now.

I kinda wish this had a hood, because if the forecast is nice enough that I take this over my regular rain jkt, I'm probably not going to want to carry my 3oz full brim rain hat. Hmm....maybe I'll add one tomorrow....or make a cuben rain hat...

Edited by dandydan on 10/19/2010 19:55:49 MDT.

Lawson Kline
(Mountainfitter) - M

Nice Job! on 10/19/2010 20:29:54 MDT Print View

Nice Job Dan. You just inspired me to build something similar.

eric chan
(bearbreeder) - F
yay!!! on 10/19/2010 21:03:09 MDT Print View

nice job ...

i think there's a market for these ...

if you could do it

- no sew to save on production time (cost) ... the seams will be sealed anyways and its not like they need to be absolutely bomber like a tarp

- use 0.74 cuben for abrasion resistance ... the weight diff is likely just a few grams

- has a hood

- shock cords around the hood, wrists, waist

- overlapping flap with velcro or something similar at the chest ... should be enough to keep splash out

- pit vents with velcro

if you could do it for a costs of 100$ US ... i really think it would sell

the trick is to market it as
1. the lightest rain anarok ever
2. the most compact rain anarok ever
3. a useful VBL layer in winter
4. super easy to repair with some cuben patch and glue (which you sell)
5. fairly durable ... more than silnyl

i mean the RHB is nice but at 2 bills .. not worth it

can ya make me one ;)

Dan Durston
(dandydan) - F

Re: yay!!! on 10/19/2010 22:05:13 MDT Print View

"i think there's a market for these ...can ya make me one ;)"

It might be possible to undercut RBH's price, but I don't think they'd be worth selling at $100. Just the materials are likely $60-$70 (inc. 2 yards cuben @ $30/yd). Then there's an hour or two labor per jacket to make them, and that's if I was able to do it way faster with tape instead of liquid adhesive. It might be possible to sell them at $125 or $150 for a hooded/pit vent version. A hooded/pit zip one from RBH would be nearly $300.

If I was to make some more, they'd be way nicer than this one since it would be made from ~2 pieces of cuben instead of 10 and there wouldn't be dry erase marker scribbles everywhere. I'd also probably run the waist shockcord inside the hem.

All this talk has me mulling over making a nicer one or two. I think I'm going to order some leaf green cuben, some cuben Tape, a little adhesive backed velcro (pit vents) and make one with pit vents and a hood.

If someone wants this one I'll sell it for $50 shipped. It's roughly a medium. I'm 5'11, 165lbs.

Edited by dandydan on 10/19/2010 22:05:46 MDT.

Steven Evans
(Steve_Evans) - MLife

Locale: Canada
Re: Re: yay!!! on 10/19/2010 22:22:24 MDT Print View

Dan. That thing is awesome. I always thought that a shirt would require a more complicated design and more joints than just 2 pieces cut the way you did it, but looking at your picture, it seems to fit very nicely.

Looks like I have another project to add to the list...thanks!

Dan Durston
(dandydan) - F

Re: Re: Re: yay!!! on 10/19/2010 22:29:46 MDT Print View

"I always thought that a shirt would require a more complicated design and more joints than just 2 pieces cut the way you did it, but looking at your picture, it seems to fit very nicely."

Yeah I was surprised too. I thought it would end up fitting poorly and perhaps restricting my range of motion, but it actually feels totally normal to wear. I had low expectations for this design and I only made it because I had a bunch of scraps on hand. I probably wouldn't have sacrificed 2 yards of intact cuben to make this, but now that I know it works I'm tempted to make another and really nail all the small details.

Cuben rain pants would also work great. They could be made using a similar technique. Maybe with 1.2oz cuben patches on the butt & knees for improved abrasion resistance...oh geez, I'm not gonna last long without placing an order for more cuben.

Edited by dandydan on 10/19/2010 22:38:30 MDT.

Luke Schmidt
(Cameron) - MLife

Locale: The WOODS
Pit zips? on 10/19/2010 22:47:31 MDT Print View

Very impressive. I'm cursious if anyone out there has experience with a non-breathable jacket with pit zips? How would it compare to a breathable jacket without pit zips for examlpe?

Dan Durston
(dandydan) - F

Re: Pit zips? on 10/20/2010 21:36:03 MDT Print View

Tough to say which would work better....a non-breathable w pit zips or breathable without vents. I'd be inclined to say non-b with vents, but I'm just speculating. Either is going to get clammy if you're hiking hard. I think it would be possible to design some generous pit vents that would work reasonably well if you were wearing a fast wicking shirt underneath. The neck vent would also help.

I think it could be made to work well enough that it wouldn't be worth carrying 3x the weight for a breathable jkt. Breathable or not, you're going to overwhelm it and get sweaty if you are hiking hard. Around camp a non-breathable jkt should be fine and you can layer it under your insulating clothing on cold nights to gain the VBL effect.

Regardless, the breathable cuben that is supposedly coming out soon will likely make existing wp/b UL rain jackets obsolete.

Edited by dandydan on 10/20/2010 21:38:35 MDT.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
bigger looser on 10/22/2010 17:53:12 MDT Print View

Nice jacket!

I would think it would be better if it was bigger around, more space between your body and the jacket, to facilitate air flow removing moisture.

I have made projects with multiple scraps sewn together to make bigger piece : )

Rusty Beaver
(rustyb) - F

Locale: Rocky Mountains
Nice Job! on 11/07/2011 10:06:29 MST Print View

Hey Dan,

I have been wondering if it could be this simple. You prove that it can be! Been wanting to do a sleeping VBL suit for ages ...maybe with .34 oz/sqyd cuben. I assume pants could be made in the same way with just two pieces.

Have you by chance made any more....or a pair of pants?


Daryl and Daryl
(lyrad1) - MLife

Locale: Pacific Northwest, USA, Earth
Re: World's Lightest Rainjacket/VBL on 11/07/2011 11:02:39 MST Print View


Thanks for taking the time to share info and photos. Will help me on my next project.

Very clever and elegant.


Art ...
(asandh) - F
Re: World's Lightest Rainjacket/VBL on 11/07/2011 11:30:33 MST Print View

Does anyone have an ETA for that breathable cuben ?

Edited by asandh on 11/07/2011 12:24:34 MST.

Adam Kilpatrick
(oysters) - MLife

Locale: South Australia
Re: Re: World's Lightest Rainjacket/VBL on 11/07/2011 19:41:11 MST Print View

Its out now Art, you can buy it from zpacks :-)

Travis Naibert
(outwest) - F
non-breathable with pit zips on 11/11/2011 13:15:17 MST Print View

Just got back from my CDT hike and saw this thread. I am excited by the design of this pullover, though I like hoods, so I think i would want one and I know that adds complexity to the design and extra weight in drawcords.

I wanted to say that I switched from a Marmot Precip to a non-breathable, cuban rain jacket from Zpacks about a quarter of the way through my CDT hike and I couldn't have been happier. Joe puts fairly long pit zips on his jackets, the hood fit well, the jacket was long and went 6 inches or more below my waist and it weighed 4.5 oz. The pit zips vent really well with a wicking base layer (LS smartwool for me) and since I had the luxury of an umbrella I generally hiked with the front zipper half way down and the hood off except in fierce wind. I get sweaty in any rain jacket while climbing, so I don't think it really makes a big difference, just walk slower if not in a hurry to minimize sweat. I like that I can wear it over my down puffy in camp while setting up my tarp and I know it isn't going to leak like my breathable jackets always do after being worn all day.

This isn't an ad for zpacks, I have no affiliation with them other than I am happy with all the gear I have purchased from Joe the last few years, I just wanted to let everyone know that a non-breathable jacket with pit zips, a long zipper, and careful temperature regulation can be just as comfortable as a breathable jacket, less weight, and more reliable at protecting insulating layers.

Keith F

Locale: Northern Virginia
Surfboard on 11/11/2011 13:29:28 MST Print View

Dan, where are you surfing up there in Canada? Must be mighty cold!