Using two down bags

Discussion in 'Sleeping Bags & Quilts' started by Diddi, Sep 24, 2018.

  1. Diddi

    Diddi Thru Hiker

    So I don't own a winter bag anymore but I do own two PD400 Bags, would me lying in one zipped with one unzipped like a quilt on top work for colder weather ?
    Pro's & Cons ?
    Has anybody thought or tried this?
    Don't want to stop getting out now colder weather is here and my weekends are free'er now daughter back at Uni..
  2. fluffkitten

    fluffkitten Moderator Staff Member

    It should work pretty well, just not sure what temp you'll be able to make it work down to.
    Diddi likes this.
  3. Dave V

    Dave V Moderator Staff Member

    How long have you had the PD400? Have you used it yet? I use to have one and am a warm sleeper, I happily used it through the winters I owned it.

    Layering down should work fine, I would suggest having the lighter bag on the top though so that it minimises any crush effect. If your a fairly still sleeper, I would imagine it to be a warm setup.
    Diddi and WilliamC like this.
  4. Shewie

    Shewie Administrator Staff Member

    There’s a formula somewhere which gives you the accumulative temp rating when nesting bags/quilts, I’ll see if I can find it
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  5. Clare

    Clare Thru Hiker

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  6. ColinHawke

    ColinHawke Ultralighter

    I used this method for mountaineering in the bigger ranges and was never cold. Back when Rab were a small Sheffield outfit I had two bags made/altered; I can’t remember the exact details but the inner bag was a tad tighter and was a simple stitch-through no-zip affair. The outer was a wider box-walled bag that I still use and have just had it reconditioned by Rab - going on for 25 years old and still great.

    I also have a phd minim bag & their double-quilt that I do the same with - similar to your idea and works fine for winter UK conditions.
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  7. Teepee

    Teepee Thru Hiker

    Pros; It works, they will dry quicker than one bag, it won't cost you a penny.

    Cons; Heavier, more hassle, may move in the night, foot end could be a little restricted.

    I have 3 dedicated double bag systems, all rated for far colder conditions than 2 x 400's.
    Diddi likes this.
  8. tom

    tom Thru Hiker

    Phd also has some info about combining down bags somewhere (sleep system) I recall - apparently this is now recommended for high altitudes Himalayan expeditions.
    Diddi likes this.
  9. Clare

    Clare Thru Hiker

    I was going to start a similar thread, but my "problem" is slightly different to Diddi's.

    I have a Revelation quilt 20 degrees, short/regular which is 137cm wide at the shoulders. i wanted to layer it up with an apex over quilt for winter, for more warmth and condensation protection. Initially I wanted a sestrals poncho 167 apex because I really fancy having a poncho quilt for sitting about in my chair but that would mean having two quilts where neither of them zip up and both are held together in winter by under straps. I can imagine this set up quickly deteriorating into sleeping on a tangle of straps and cold slipping in. Also the wide sestrals is 140cm, only 3cm wider than my Revelation, although I suppose I could ask Marco to make it wider, although that may make it awkward in poncho mode.

    But apart from my poncho lust, wouldn't it be more sensible to cover the Revelation with a zip up apex, e.g. EE's Convert, which is pretty wide, and have the Revelation and its straps floating around inside the Convert.

    Ideally i would have started with a down Convert or other zippable quilt, zipped it up for winter and put an apex Sestrals Poncho on top, but that is unfortunately not my start point.

    Edit: Yes I have noticed @oreocereus quilt for sale, but it's only 132cm wide, so even narrower than my Revelation,

    Any thoughts please? who sleeps with non-zippable quilts in winter?
    Last edited: Sep 24, 2018
  10. oreocereus

    oreocereus Section Hiker

    I believe AS Tucas (and Gramxpert) design their quilts with layering in mind, having snaps to attach two quilts together (or something like this). Does the revelation have any snaps that perhaps Marco could sew corresponding snaps to the poncho quilt? It might compromise its functionality as a poncho if it means moving the location of his snaps from their optimal position, though.
  11. Clare

    Clare Thru Hiker

    snaps at shoulder and two above footbox. The middle section is elastic straps. Maybe I should just sew a zip to the Revelation myself and turn it into a pseudo-convert without baffle and trash it's re-sale value with my home sewing....
  12. WilliamC

    WilliamC Thru Hiker

    We do, a Zpacks Twin quilt with a Zpacks custom Twin Apex quilt on top. The two join partly buy matching snaps but also using that velcro that sticks to itself to button holes that Zpacks quilts used to have. We never use the straps on any of our quilts so I don't remember how they attach on EE quilts, but I'd imagine there is some way of fastening them together.
    Having the over quilt built larger is not much of an issue IMO. The upper quilt can be fastened so that it doesn't come completely to the edge of the lower quilt, which will be under you anyway. And didn't BPL find that down can be compressed a fair bit before it starts losing significant insulative properties?
    Clare likes this.
  13. DuneElliot

    DuneElliot Section Hiker

    Not that I plan on ever camping when it gets that cold but if I ever did I would go with my 30* synthetic quilt under my 10* down quilt. Down quilt is bigger and more-easily compressed so it makes sense to have it on top.
  14. HillBelly

    HillBelly Section Hiker

    I bought a top bag for this specific purpose - a Rab Module, which is great and fits in my Rab Alpine down bag a treat, boosting performance in winter. Rab did a couple once upon a time, but no one (I know of) seems to do a top bag any more. I couldn't justify a full on winter bag for the small amount of times it was used, so now I have a workable system of double bag for winter, single bag for most of year, and should I ever get out on a balmy summer's night I can use the Module on its own.
    Clare likes this.
  15. WilliamC

    WilliamC Thru Hiker

    @Clare I just checked on our EE quilt and it jogged my memory. Both the EE and Zpacks quilts use these buckles to attach to the straps. The female part is attached to the quilt. What we did was get the male parts (took them from the straps, you might need to buy them) and used grosgrain to larks foot them to the Apex quilt, then just snap them to the female parts on the down quilt.
    Clare likes this.
  16. Clare

    Clare Thru Hiker

    Very cunning. This all sounds very useful, I've got to go out now but will give this some focus later. Thanks.
  17. Clare

    Clare Thru Hiker

    As i understand it the consensus is to have the apex on top because it is condensation resistant (or at least performance is not so badly affected by damp), yet breathable enough to let body moisture that has gone into the down layer, escape. One of the main objectives is to avoid the effect of general damp and condensation affecting the loft of the down bag, so it is "protected" under the safety of the Apex.
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  18. Enzo

    Enzo Thru Hiker

    I guess sweat/breath condenses when it hits the cold so would condense in or on top of an apex over bag, saving the down. I use an apex over bag/bivvy. I can get a neoair in there too. Works great but native width of fabric was insufficient so had to run two widths lengthwise.
    Clare likes this.
  19. DuneElliot

    DuneElliot Section Hiker

    I guess I was thinking the other way around.
  20. Jmws

    Jmws Ultralighter

    I haven't used a true bag in winter for a couple of years, preferring instead to use my loco libre 0 degree ghost and my 20 degree burrow on top if temps get really low. Have loops on both which I can use to attach together. Not been cold yet ... Then again I've not been high up and I'd don extra clothing layers if truly cold

    Like you I've been toying with the idea of an apex overquilt to solve potential condensation but yet to pull the trigger.

    Have you considered the Nunatak Gamut? It's a climashield apex quilt specifically designed as an overquilt offered in 35°, 42°, 50° options.
    Clare likes this.
  21. Enzo

    Enzo Thru Hiker

    I have an apex 67 over quilt, with a hole to stick your head thru so you can use it as a camp poncho (pun intended)
    M10 outer, 10d very breathable taffeta inner, kam snap closure, sewn footbox. 360g dark purple. 160cm wide at the top. 1537816392664191713818.jpg
    Not my finest work but not as bad as I remember.
    Fits me at 5'10
    £20 delivered if anyone fancies trying out the concept.
    Last edited: Sep 24, 2018
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  22. Clare

    Clare Thru Hiker

    Oh go on then, it would be rude not to. I’ll pm you
  23. Diddi

    Diddi Thru Hiker

    Thanks for all the input and its definatley something i will try now.
    Need to find a way to stop it coming off ( velcro maybe ) straps no..
    Anyway looking forward to experimenting and getting out in colder weather.
  24. ZenTrekker

    ZenTrekker Section Hiker

    I would think that 2 x 400 bags would be quite heavy and very, very warm, you may be better off with a smaller/lighter summer bag. I used to use a combination of a RAB Quantum 200 mummy bag with a RAB top bag (400 grams of down in total). I once used this combination in temperatures down to about -3˚C and I overloaded the system (i.e. I was too hot) I ended up with two very wet sleeping bags. One of the reasons I changed to a quilt was that I can vent my sleep system if I get too warm.

    I use a Cumulus Quilt 350 and its good down to just below freezing. I've recently bought a Cumulus Magic 125 down liner bag. Haven't tried it in really cold conditions but I reckon the combination would take me down to around -10˚C. Together they weigh 800 grams with 375 grams of Polish goose down.
    Helen E, Diddi and Enzo like this.
  25. ZenTrekker

    ZenTrekker Section Hiker

    One method you could use to secure your open bag, is to get some Stick-On Mitten Hooks from Tread Lite Gear I used these to secure my RAB Top-Bag to my sleeping mat, I removed the plastic hooks and threaded shock-cord through the loops and then around my mat.

    Alternatively you could tie some small plastic toggles onto the mitten hook loops (removing the plastic hooks first) and then use some button-hole elastic, stitched together as a continuous loop and wrapped around your sleeping mat. The plastic toggles fix to the elastic and can be adjusted to suit.

    Button Hole Elastic can be found on Amazon
    Toggles Ties and Stoppers&cct=&TypeSearch=&subcat=

    Attached Files:

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