Another down 'mummy quilt'

[undercling-mike]

I just finished my latest down quilt a couple of days ago, what I'll call a 'mummy quilt' due to it being shaped in a similar way to mummy sleeping bags. After my previous quilt (http://bushwalk.com/forum/viewtopic.php?f=53&t=20711) I felt that the mummy shaped quilt was a little more effective in wrapping around the user, making it a bit easier to use. This time I used longitudinal baffles as my feeling is that down is more likely to shift during the night to the edges of a quilt with lateral baffles than to shift towards the foot end of a quilt with longitudinal baffles, it also means that a differential cut can be introduced naturally by altering the baffle spacing of the shell and liner.

The specs on this one are:
Shell fabric: Hyper D 1.0 lime green
Liner fabric: Membrane 10 Navy
Fill: 340g (12oz) of 800 fill power goose down
Length: 183cm (72"), Length seems great for me at 178cm (5'10"), it comes up to my forehead lying straight and would suit users up to 183cm (6')
Max. width of liner: 132cm (52")
Sewn in, angled (anatomic, haha) footbox with no sewn through seams
Full length differential cut
Weight: 520g (18.3oz)
Temp rating: I think it'd be good for me to just a bit under freezing, say -2 (by my own experience, comparison to other products and dead reckoning...)

Seen here on my trusty Neoair original, regular size.

Uses pad strap attachment system with elastic webbing and flat centre release buckles to hold the quilt to the pad and to adjust how tightly the edges of the quilt are pulled in.

Double snap neck closure and elastic draw cord with the cord exiting at the back as is my preference (to keep it out of my face, can reach around to adjust if necessary). All snap and buckle mounting points are internally reinforced with gross grain ribbon.

Rip-guard triangle at the top of the footbox and a snap to close the footbox up a bit higher if desired. Footbox is sewn up about 43cm, plenty of depth in my opinion and allowing the user to put a foot in and out in warmer conditions without shifting around the rest of the quilt.

Closer look at how the pad attachment system works.

Anyway, I've made quite a few down quilts now and this one is the best yet. I see it as my evolution of what's on the market to fit my ideas and preferences. It was made with the idea in mind of producing quilts of the same design for sale, so it's kind of a design prototype and it was also a good challenge to come up with the best design I could. Needless to say I spent a heap of time working on the design. Having made this one there's nothing major I'd want to change, maybe a couple of minor tweaks but I'm really happy with it. Now I need to work on turning the pattern into templates and figure out the best approach to sewing some of the more fiddly areas, but I'm pretty excited about it!

[Bluegum Mic]

That is amazing. Perfection right there (even the colours). Brilliant job

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[whitefang]

Absolutely brilliant. I love the colours.

[Nuts]

Nice job mike, it looks lofty and warm for so little weight, i too like the colour.

[neilmny]

A work of art Mike. Very classy.

[simonm]

Very, very nice.

[Lizzy]

Very professional!!!

[undercling-mike]

Cheers guys, I'm a big fan of the colour scheme myself. It's great that over the past couple of years since I've been into MYOG that there has been a huge expansion in the fabrics and colours available to the public. There are so many good and interesting combos possible now and hopefully with further expansion to come.

[Alittleruff]

Looks fantastic. Someone is just a bit clever I'd love to hear about how you go selling them Congrats on piecing together a great design that you have obviously thought long & hard about.

[Orion]

Very nice indeed.

It's essentially identical in size, weight, fill and estimated temperature rating of my own quilt. One thing I routinely do is shake the quilt out each night, to "center" the down. I've wondered many times if either vertical baffles or vertical tubes would be better. To be honest, I'm not sure how much good my evening bag shaking does. The quilt puffs up even when I omit this step. And by the same token, the down tends to shift to the sides whether I shake it first or not.

Now maybe you can tell me/us, after some time, how well the vertical baffles work in practice.

[Moondog55]

Nice
Very nice indeed.
Orion I've used vertically baffled bags in the past and they work quite well and work better if a little overfilled. My very first down bag; the Kimptons Arctic; had vertical baffles

[Orion]

I have no doubt that vertical tubes work. I was just wondering whether or not they are noticeably better than horizontal tubes. And if they are, why are they so uncommon?

[undercling-mike]

It's interesting that vertical baffles are so uncommon but there are some, the Marmot Plasma bags for instance and the Enlightened Equipment quilts use a modified vertical system. I guess it's partly to do with convention, my previous ones were all horizontal baffled because that's the standard. After making this one I really like the sleek look of the vertical baffles and it has a number of advantages in the construction. Fewer but longer lines of stitching tend to be quicker and you can introduce a differential cut very naturally by changing the spacing of the baffles between the shell and lining, no need to take periodic tucks in the baffle material when sewing it to the liner, which was rather time consuming.

As for performance of the baffles I can obviously only give initial impressions at this stage but I've gotten in the thing and tossed and turned and at the moment I think it's quite a bit better with respect to down shift. If you thrash around enough it's definitely still possible to make it shift but the top to bottom direction just seems less susceptible to it than side to side. It'll still be important to make sure the down is evenly distributed when you pull it out each night, maybe even more so than with horizontal baffles.

The other thing is that ever since my first few quilts I've been a fan of using shorter baffles for the amount of down than is published in some specs/reports. I've often seen down fill calculated with a factor of 1.3 compared to baffle height but I use more like 1.7. For instance this quilt has approx 1.5 inch baffles but a calculated fill height of 2.55 inches. This seems to work well for me and I do move around a fair bit at night.

[undercling-mike]

With regards to selling quilts I'm planning to start small time and when I'm ready I'll post in the Specials, Discounts, Adverts section here to solicit orders. Initially I think I'll only be able to offer the 'regular' size shown here but in a few different temp ratings and hopefully if all goes well I can produce larger and smaller sizes as well. The main thing I need to do now is to turn my pattern into a series of templates for marking and cutting the fabric.

[Orion]

...they...work better if a little overfilled.

The other thing is that ever since my first few quilts I've been a fan of using shorter baffles for the amount of down than is published in some specs/reports.

You'd expect a smaller volume tube with equal fill to develop voids less often, regardless of the tube orientation. I think there's a trade-off between obtaining maximum initial loft and anticipating the loss of loft that inevitably occurs due to moisture or dirt. My quilt, now three years old, is less fluffy than when new. It weighs more too. Probably past due for a little bath!

[north-north-west]

I wish I could sew anything as beautifully as you've done that quilt.

[undercling-mike]

My quilt, now three years old, is less fluffy than when new. It weighs more too. Probably past due for a little bath!

Weigh it before and after putting it out in the sun for a while, much of the weight increase is probably absorbed moisture, although the down will re-absorb pretty quickly in humid conditions. Also if you can fluff it up in a dryer then you might be surprised how it fluffs up again. May be worth a try before going with the full wash.

[jobell]

Wow, wish I could sew like that! I think there's a good number of us who would be happy to support an Australian manufacturer rather than ordering from overseas. Hope it all comes together for you... and us aspiring quilt buyers as well. [WHITE SMILING FACE]

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[Orion]

Weigh it before and after putting it out in the sun for a while, much of the weight increase is probably absorbed moisture, although the down will re-absorb pretty quickly in humid conditions. Also if you can fluff it up in a dryer then you might be surprised how it fluffs up again. May be worth a try before going with the full wash.

You might be right. I tried this last year actually:

528g - Aug 2011 (original weight)
541g - Aug 2014
511g - after time in a warm dryer
545g - next morning

The ambient humidity pushed the weight right back to where it had been before the dryer.
The thing I don't know is what a post-dryer weight of the original bag would have been.

I repeated it this year:

543g - Oct 2015
510g - after time in a warm dryer

No change since 2014.
I'll use that as an excuse to not wash it for another year.


Anyway, your bag looks really good. I'm sure you'll be able to sell those.

[undercling-mike]

Thanks for the support guys, I'm looking forward to getting some of these out into the wild

As for the moisture absorption it is quite a lot, a shot glass full, but I don't think it causes any real problems, you just have to plan for it and fill accordingly. The nylon quilt shell absorbs some humidity as well. I try to fill for the dry weight of the down since this is how the fill power is measured.

Also, go ahead and feel free not to wash your quilt for another year! Maybe the time to do it is when you start to become disappointed with the performance or the shell just gets too dirty or the funk too great.

[Orion]

A shot glass full of water sounds like a lot but it's only about 6% by weight. I had to determine the moisture content of some filter papers one time and they, while seemingly bone dry, held about 5% moisture. The environment here is usually around 60-70% relative humidity and 10-25°C. Kind of like Hobart, actually.

[undercling-mike]

Yep, about 6% is in line with my experience.

[Moondog55]

Mike are the footboxes on the new quilts large enough to accommodate a half bag?
Just another way to extend the range of a 3-season sleeping unit into the hard water months
As an aside have you noticed how similar to S2S's Traveler the new Western Mountaineering overbag is? but just a touch bigger
Christmas is almost here and the S2S quilts should be here soon; I wonder what they will be like

[Nuts]

I'm liking this hydrophobic down (despite some neg reviews).

[Orion]

Nuts, I was wondering about that; how much less moisture Activ-Dri down would absorb from the air.

What are the negative reports?

[undercling-mike]

Some say the hydrophobic down can be a bit more 'clumpy' and harder to loft, Z Packs have stopped using it in their bags for instance but plenty of other brands are happily selling it and plenty of customers are happily using it. Many comments singing the praises are from people who haven't really had to test it, i.e. they get a peace of mind benefit. I have no doubt hydrophobic down will resist wetting much better than standard down and dry out faster if soaked, but the vast majority didn't have problems using regular down before. Some benefit to the consumer but I'd say the biggest benefit has been to marketing departments...

From what I've read I think the hydrophobic down is great at resisting liquid water but still absorbs some vapour from the air, I suspect the amount of absorption varies with different sources of down anyway and the hydrophobic treatment may reduce absorption a bit. It'd be great to see some proper test results of course.

[Moondog55]

Well if Nikwax counts I've been using hydrophobic down for long, long time
It's biggest advantage is the vastly improved drying time if it ever gets wet

[Orion]

Thanks for that, Mike.

I've been skeptical of it partly because regular down works so well, at least in the relatively dry climates I visit. It's so warm for its weight, nothing man-made has equaled it. Even Tasmania which is kinda wet sometimes doesn't put a damper on my down quilt or bag. In more seriously wet conditions I go synthetic. I've spent nights in a soaked synthetic bag still warm and relatively happy. A down bag, and I suspect a "dry" down bag too, would be a serious disappointment in those circumstances.

[Nuts]

Just a RAB jacket iv'e used last summer for a few weeks and a smattering of days since, and a week in late sept. Can't search just now but I thought it was more that the performance went downhill after washing. But, iirc, there are a few different 'dry downs'.

I have had it pretty wet (wearing through a shower) and i was more impressed with it not clumping, it stayed where it should and dried like synthetic. My theory was that the separation would make the jacket safely machine washable (which I did a few weeks ago). All good so far (early days and nothing measured on humidity front).

Marketing though.. can't ignore that for a commercial product, good reviews or bad, they don't really even need to be long-term to sway buyers.

[undercling-mike]

I forgot to answer your question about using a half bag in the quilt Moondog, so I'll answer that. The footbox of this quilt is slightly larger than the one on the halfbag I made for you so I'd guess it should work OK and give a decent boost to the warmth. One advantage of the vertical baffles I think is that if you need to push the temp rating by a few degrees you can shift a little of the down down to the feet/legs/lower torso and then wear an insulated jacket to make up for the slightly reduced loft in the upper part (kinda like the concept of the FF Vireo bag).