Cuben / Down Quilt

[Ashley Brown]

Thanks for the pic Greg.

Steven, will be very interested to hear how you go with the sweating/moisture issue. Seems like you will need to treat it like wearing a VBL… ie. only take it out in temps where it is cold enough that you won't sweat at all, and may need a bit of extra clothing underneath.

Give us a report back when you've had a chance to use it in the field!

[Lynn Tramper]

Ashley, I have experimented with sleeping under a piece of quilt-sized cuben in warm weather, and haven't found it to be a problem. I just stick my arms/feet/legs or whatever out of the fabirc to adjust temps and perspiration, just like a normal quilt. This is also how I sleep at home (constantly adjusting my duvet as I heat up and cool down), so it comes naturally. If you are a sound sleeper who falls staight asleep and doesn't normally move all night, then you might have a problem with over heating.

Greg, I can't remember exact measurements, but when I originally worked it out I was planning on taping the whole quilt….that baffles top and bottom, plus sides and footbox. So it was a significant weight gain of around 150g. But the idea of making a "no sew" and waterproof quilt is also quite appealing…I think I might just tape the baffles on the inside and not worry too much about the outside. I don't plan on sleeping out in the rain without a shelter!

[Tim Marshall]

instead of the cuben tape consider a glue. Steve what is that glue you've been working with? It should be much lighter than tape.

-Tim

[Steven Evans]

The adhesive I used was Hysol U-09FL. It won't be a fun task, but it is possible!

FWIW, Tim's sewing of the cuben fabric on the quilt seems stronger then the seams on my bivy (which was sewn by my mom). I can't comment on what was done differently on the two but thought that would be of interest to some.

The moisture issue is something I have been thinking about but really won't know until I try it out – it may work out to be fine or perhaps the thing fills with condensation – who knows.
I have been messing around with the quilt and the cuben feels pretty good against the skin. The fabric is so thin and light that it's not the same feeling as having other WP materials (ie. silnylon, plastic sheet) up against you.

I'll try to get morepics up this weekend.

[SIMON TEW]

If the Momentum strip was on one edge of the quilt rather than the top, it might give slightly improved weather protection. So with say a poncho tarp pitched as a half pyramid, you'd have the all-cuben side facing the door, just in case the wind direction changed.

[Tim Marshall]

if rain is landing in the center of your quilt you need a new shelter.

As fasr as how i sewed the cuben to make a stong seam. I folded it over to sew through multiple layers. I did mostly 6layers with some 4 and a couple only 2.

-Tim

[Edwin Short]

I have a down uq, nunavit modified took off the foot box, (is kinda a 3/4 uq)I sewed a .33 cuben bottom to it, protects from spindrift etc works as a wind barrier too. adds very little weight. My oq is a nunivit down, maybe sew a cuben ,momentum top to this could still breathe some would be super warm I bet. ah the ideas that come forth! gnome

[Lynn Tramper]

"if rain is landing in the center of your quilt you need a new shelter."

Agreed. Although shelter condensation occassionally drips onto the centre of my bag, most of the moisture that causes problems is from the sides and bottom of the bag. I really like the idea of a small, breathable strip of fabric down the middle of the bag. I tried making a mock-up with propore fabric along one edge, but it wasn't breathable enough to fully loft (or unloft) in a timely fashion, so I guess something like Momentum will have to do.

[Steven Evans]

Finally got around to taking some photos with me in the quilt.

For size comparison, I'm 6'3" tall and about 185lbs. The quilt easily comes up past my chin and wraps nicely around me. Side sleeping or flopping around won't be a problem either, but I've been using the Arc AT for the past 2 years, so I'm used to a smaller quilt.

[Tim Marshall]

how do the bungee under straps work?

-Tim

[t.darrah]

Steve,
Did you have Tim use a sewn footbox or a system that allows the tarp to be layed out flat, such as a zipper or snaps?

The coverage looks good which for your size is somewhat of a surprise to me. I'm much smaller at 5'10" and 145 lbs and my nunatak Ghost provides good coverage but with little to spare.

[Tom Caldwell]

Why didn't you put the momentum stripe on the inside and outside?

[Steven Evans]

Tim,
The elastic bungees are awesome. Much more user friendly then the straps on my Arc AT. This may just be personal preference, but I really think that a bungee strap is the way to go on a quilt. Keeps it nice and snug – just look at the pictures!

Tom,
Tim did a sewn round footbox for me. I can't remember off hand, but I think it is about 15" in length. I actually really like the zipper idea (I think Kevin put one on his quilt after Tim recommended it), but as you know, this is the "WLQ-1" and I couldn't have a heavy mechanical device like that on it :)

Hi Tom,
Maybe I'm not getting the whole picture, but the only benefit I see from having a strip of M90 on the inside of the quilt aswell, would be to assist the speed of lofting. The downfalls would then be moisture build up, additional cutting and sewing, and a heavier weight.
Originally, when Tim and I were planning/designing the quilt, we didn't know how much breathable fabric was required to ensure a full loft. We went with the single strip down the middle, and it works great. The full cuben inner acts as a vapour barrier, if there were M90 on the inside then you would lose that effect.

[Tim Marshall]

is there enough foot space or do your feet push on the quilt collapsing the loft?

-sorry the footbox was smaller than planned-

-Tim

[Tim Marshall]

Also, I was thinking that if there is ever a WLQ-2 maybe the top baffle would be cuben with mesh baffling. I am slightly concerned with you exhaled vapor soaking into the momentum strip. If the baffle next to the face was all cuben it would keep the down safe, but it would require a mesh baffle vs cuben to loft.

I'll be interested in your field report to see if this is necessary or over thinking.

-Tim

[Kevin Egelhoff]

Tim,
I love how you are really thinking through all the possible revisions for WLQ-2. All sound like great ideas even though Steven is probably going to love version 1 !!!

Only thing I'm bummed out … why couldn't you two have come up with this GREAT idea about two months ago before I just made my quilt !!!!

So, WHO has dibbs on WLQ-2 ??? Just for curiousity sake … shoot me an email with the details on making one for me !!
Kevin

[Tim Marshall]

If you want one let me know. One like Steven's will run ya $400. (i know ouch, but look at Nunatak's prices then think about the cost of cuben and down when you must pay retail like me)

I still think you are better off with the quilt you have now. 2 reasons, 1 you made it yourself and i think that whenever possible it is nice to have gear that you make, and 2 there is no way a quilt like the WLQ will be as universal as the one you made. The WLQ will have a temp zone much narrower in range than a standard down quilt. It will be much too hot and harder to vent when it is warm and if the temp drops after you start to sweat it can even be a safety issue.

I think that the cuben quilt it awesome, and has a place in your gear list (yes please buy one!) but i think if you could only have 1 quilt it should be a 20-30* down/momentum job. It will be much more universal in its function, heavier sure, but if you can only have 1 i'd want 1 i can use in 75% of possible conditions, not 25%.

The cuben quilt will shin when the temps drop. It will allow the same amount of down to go down 10 more degrees and quilts of the same weight to be perhaps up to 20*(a rough guess) warmer as the weight is almost all down and not fabric.

For all season use, stick with momentum, but for cold weather cuben is going to be the thing to have.

-Tim

[Steven Evans]

The foot box is perfect. I wouldn't want to go any smaller, I haven't measured it but if it is 32", then it is the same as my Arc AT which I can still wear a pair of down booties with my size 11 feet. It's tight, but I do it regularly.

We'll have to see about moisture entering the M90 strip at the top baffle. Good idea using a cuben for the final segment, but if temps are getting below 5*C (40*F) I am almost always wearing my balaclava by then which "should" catch alot of the moisture. I will definitely let you know how it goes.

[Frank Perkins]

Very cool guys. So now I'm trying to figure out what the true weight savings are. The closest quilt that matches this would be the Arc Edge, size Large with 2oz overfill: http://www.nunatakusa.com/site07/arc_products/arc_edge.htm That would bring the weight to 14oz. The Arc Edge would be about 3 ounces heavier than your Cuben quilt.

Does this mean that you saved 3 ounces by simply using Cuben Fiber over a 100% Quantum quilt?

Why don't you think Nunatak, BPL or MLD would offer a cuben fiber quilt? Is there something that they found in Cuber Fiber sleeping quilts that they don't feel would make good sleeping system?

[Tim Marshall]

The reason you don't see companies using cuben is the same as why you don't see them using silnylon. Most people won't be comfortable in a waterproof vapor-barrior bag. It takes time to learn how to use it and you have to plan more for the right temps that you won't get too hot. It is not a simple grab it and go material as if you take it out too hot you will be sweaty and that will make you mad and you will say "that *darn* BPL cuben quilt is crap". But what really happened is you didn't know how to use it right.

I have a feeling that if enough home builders and custom makers (like me) are making these and there is a market for them that the companies you mention will follow.

-Tim

and yes the weight savings comes from the use of cuben, the entire shell before down only weighs 3.1oz which is pretty dang light.

[Kevin Egelhoff]

Still thinking about this Tim but you brought up a lot of good points. I just don't know how well I would do in regulating the temperature with the VB especially since I usually don't see temps that often like Steven.

That price seems more then fair when you figure in the cost of Cuben, down, and the time it takes you to make one!

Also, I think the calcualted weight savings in making the exact same quilt in 0.8/1.0 material vs both sides made of Cuben are much more then 3 oz. ??? Right Tim ?

Kevin

[Tim Marshall]

as far as weight savings lets look at the weight of 5yds of fabric.

total square yds =1.5(54" width)x5=7.5

cuben .33×7.5=2.475

momentum .9×7.5=6.75

quantum .8×7.5=6

if the size of the quilts are the same and all the snaps and drawcords are the same the only differences in weight will be between fabric choices.

Even though the EDGE and WLQ have the same dims the EDGE uses a cruved shape and the WLQ a straight tapered so the amount of fabric used will vary slightly between the 2.

The savings of using cuben will be in the 4oz range, which for a summer quilt that uses 6oz down or less won't matter much, but when you want a quilt for the cold north those 4oz combined with the vapor barrier system will give you a much warmer quilt than a similarly weighted one with a breathable shell.

Imaging a quilt with 12oz of down that only weighs 15oz, and adds VB. That will be a very warm and light winter setup. (maybe it wouldn't be a quilt in the winter, a top bag probably, but you get the point)

-Tim

[Matt Lutz]

Wait, the baffles are made of cuben, too? Did you use the 0.7 oz/yd stuff from Thru-Hiker? Crazy.

[Brad Groves]

Tim (and Steve) this thing is sweet! And no, there's no way you'll get a quilt with 8 ounces of down, these dimensions at this weight. The one I'm working on is over a foot shorter, uses only 6 ounces of down, and will probably end up a good couple ounces more than this.

I was thinking about making a cuben bag, but I have this habit of testing limits. I sewed up a little .33oz cuben pouch and pulled on it, trying to simulate pulling it out of a stubborn stuff sack. The pouch tore at the stitch lines. Now, I know all sorts of people here sew Cuben–so the question is, why isn't their stuff (your quilt, Tim) tearing at the seams? Maybe I used too large a needle and thread? Does thread type matter? Or is this just a matter of stuff it loose and be baby gentle?

Love the weather resistance and VBL combo…

[Tim Marshall]

baffles are cuben. I used .33cuben for all and M90 from thru-hiker for the strip. I use guttermond 100% poly thread

As far as strength goes a quilt won't get stressed along the seams much at all. The stress will be across the panels as you lay under it.

Stuffing and unstuffing may stress the fabric some, but since the material is airtight the best way to pack it is to roll it with the M90 up so you can squeeze the air out. Then slide it in the sack or tie it with some scrap cuben.

Pulling cuben apart at the seams is very possible, however not as easy as tyvek. Try to pull some tyvek apart and you will never us it for anything again. Not even on a seam pull in the middle of a square of it, slices right apart. The cuben will pull apart at the needle holes and i used the smallest needle i could get and kept the spacing fairly close together so that the stress was over more holes (not sure if that is best)I think that if making a shelter of .33 this will be an issue and many people are gluing/taping to solve this problem. However, i don't think the seams of the quilt will be under much stress at all (time will tell) If you paid $400 for a quilt like this i'm sure you would baby it a little, so it's not so bad that it is a little more fragile than other things. It is the nature of being the lightest. The lightest thing in every category always gets a bad rap for being weaker, but that's the nature of being the lightest. Each of us must just find a balance we are comfortable between weight and durability.

-Tim

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