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RE: [Hammock Camping] Frost free?

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  • Ed Speer
    M2b1997, I ve had the same experience many times as well. Frost on the outside of a sleeping bag, hammock, underquilt or on the tarp is natural when the air
    Message 1 of 13 , Jan 6 7:44 AM
      M2b1997, I've had the same experience many times as well. Frost on the
      outside of a sleeping bag, hammock, underquilt or on the tarp is natural
      when the air temperature drops below freezing, there is no wind & the
      outside humidity is high enough for the dew point to be reached. Frost near
      your head & mouth is probably frozen condensation from your expelled
      breath-not much you can do about that. Some of the frost elsewhere on the
      sleeping bag, hammock or underquilt is probably frozen moisture from your
      body's insensible perspiration that has been driven thru your insulation
      layers by your own body heat, condensed on the outermost fabric & then
      frozen by the low outside temps. This is normal & beneficial-it means your
      insulation layers are not trapping excessive body moisture, which as you can
      imagine can be a serious problem. Escape of some of your body moisture thru
      your insulation layers happens every night, only at warmer outside temps the
      moisture does not freeze & it may even evaporate entirely (especially if
      there is some wind or the outside humidity is very low). Of course, a
      sleeping bag or hammock wet on the outermost fabric can be a bit of a
      problem if it has to be packed up that way the next a.m.-I'll often lay mine
      out during a rest stop on the trail the next day to dry it off. In your
      case indoors, you might leave a window open for added drying ventilation
      during the warmer temps of the day.



      High humidity fog & moisture escaping from the ground can also contribute to
      the dew & frost buildup on the outside of a sleeping bag or hammock-but
      since you're hanging indoors, this should not be part of your problem. If
      there is frost on other surfaces in your sleeping room, then high outside
      air humidity may be the problem.



      For those of us who winter camp in the hammock, we're concerned about any
      loss of warmth. The fact that body moisture is being lost thru the
      insulation (as evidenced by frost in the winter) means that some of our body
      heat associated with that moisture is also being lost. But stopping that
      kind of heat loss is a major serious undertaking that is difficult &
      controversial. Here we enter the world of vapor barriers & a whole new
      topic. I'd love to see vapor barriers discussed on this List for I know
      many of you have tried them with varying results. Of course, sleeping pads
      are partial vapor barriers & we all use them when it gets really cold. I
      also often use a plastic sheet for a partial vapor barrier for added warmth
      on cold winter nights in the hammock.



      M2b1997, you might have success stopping some of the frost (that which is
      your escaped, condensed & frozen body moisture) by using a suitable vapor
      barrier inside your sleeping bag-never close it over your head or you WILL
      suffocate! Frost due to your expelled breath will still be present. But
      please do some research & planning first as this will be a real shock when
      you wake up dripping wet in the morning! You & your sleeping clothes will
      be wet & warm, but your sleeping bag should be mostly free of frost! The
      problem comes when you get out of your vapor barrier/sleeping bag & meet the
      subfreezing air! For this reason, most folks prefer NOT to use vapor
      barriers. However, they are a proven winter camping technique---I only wish
      I were more experienced with them...Ed



      Moderator, Hammock Camping List

      Author, Hammock Camping book

      Editor, Hammock Camping Newsletters

      Owner, Speer Hammocks Inc



      _,___



      [Non-text portions of this message have been removed]
    • m2b1997
      I agree Ed, that the moisture freezing around the mouth is to be expected, hence why I wasn t concerned by it or even thinking anything about. I was surprised
      Message 2 of 13 , Jan 6 8:44 AM
        I agree Ed, that the moisture freezing around the mouth is to be
        expected, hence why I wasn't concerned by it or even thinking
        anything about. I was surprised by it for a second or so, night one
        or two, until I realized I should be seeing it.

        The sleeping bag seemed dry, just cold, as could be expected given 14
        degrees. It was the hammock though that had the frost on it, other
        than around the mouth. That's why I'm a bit perplexed. I hadn't
        thought about the body heat being lost but that does make perfectly
        good sense.

        Around the face the frost was the worst...but I still had it, ONLY on
        the hammock, all the way down at the feet. The weather was cloudy
        turned clear by morning, no precip overnight. In the several times I
        woke up overnight it was anywhere from partly cloudy to clear. I'm
        not sure what the dew point was. I'm going to have to pay a little
        more attention the next time and see if I notice that being the true
        culprit as it doesn't seem like the breath should be able to make it
        all the way down to the feet.

        Just one strange/stupid curiousity that has come up in my mind. In
        the case of winter camping would you be better off with a cotton
        versus a nylon hammock? Yes, this seems like a real dumb question,
        but think about it for a moment. During the summer months, nylon
        only, I wouldn't consider anything else otherwise, simple because of
        the rain. Winter months though, when you find yourself in a
        situation like I did last night the cotton hammock would have the
        tendency to absorb the moisture instead of the sleeping bag. This
        would keep the sleeping bag drier. There's nothing 'waterproof'
        around you to keep the moisture in so it collects on the sleeping
        bag. Am I wrong on this thinking? Is that why the hammock had the
        frost at the feet but the sleeping bag was dry? The thought just
        came to me as I was typing this.

        MEANT 2B
        GAME '97
      • Ed Speer
        Cotton vs. nylon hammock might make a minor difference on the amount of moisture collecting on the outer side of the fabric, but not much. But you re right
        Message 3 of 13 , Jan 6 9:34 AM
          Cotton vs. nylon hammock might make a minor difference on the amount of
          moisture collecting on the outer side of the fabric, but not much. But
          you're right that a cotton hammock around a nylon sleeping bag might tend to
          absorb more of the body moisture that condenses on the outside fabrics. I
          guess you might end up with a wet hammock & a drier sleeping bag. But since
          they're still in contact with each other, they're both be wet. I find that
          a small chamois cloth is ideal for wiping off the condensed moisture that
          tends to bead up on nylon fabrics-especially those with durable water
          resistance (DWR) treatments. I use it in the am before taking down the
          hammock.



          But remember that your body moisture will be driven to the outermost fabric,
          no matter if it is cotton or nylon. In most camping temperatures, as long
          as the fabrics are breathable, your body heat will drive the body moisture
          to the outermost fabric. I suspect both your sleeping bag & hammock had
          moisture (frost) on them where they were directly contacting the outside
          air-where the hammock fabric directly covered the sleeping bag fabric, only
          the hammock fabric should have had frost. It's usually the outermost fabric
          that collects the moisture-it's the fabric directly in contact with the cold
          air that collects the condensation. The warmth from your body is enough to
          drive your body moisture all the way thru multiple layers of breathable
          fabrics; except in extreme cold conditions. Only when your escaping body
          moisture meets a vapor barrier or a cold interface like the freezing outside
          air, will it stop & condense. In extreme cold situations, that cold
          interface could occur inside your insulation! Members of arctic expeditions
          sometimes find that their very, very thick sleeping bags keep getting
          heavier and heavier each night-it's because their escaping body moisture
          meets the cold interface & freezes before it reaches the outside of the
          insulation; they end up with ice accumulating inside the insulation & no way
          to get it out!



          Your reply suggests one of my favorite tricks for cold weather
          camping-wicking long johns. This fabric moves my body moisture to the outer
          side of the fabric leaving the inner side of the fabric (the side against my
          skin) dry. I'll even use wicking long johns inside a vapor barrier bag to
          keep wetness away from my skin..Ed



          Moderator, Hammock Camping List

          Author, Hammock Camping book

          Editor, Hammock Camping Newsletters

          Owner, Speer Hammocks Inc



          From: hammockcamping@yahoogroups.com [mailto:hammockcamping@yahoogroups.com]
          On Behalf Of m2b1997
          Sent: Tuesday, January 06, 2009 11:44 AM
          To: hammockcamping@yahoogroups.com
          Subject: Re: [Hammock Camping] Frost free?



          I agree Ed, that the moisture freezing around the mouth is to be
          expected, hence why I wasn't concerned by it or even thinking
          anything about. I was surprised by it for a second or so, night one
          or two, until I realized I should be seeing it.

          The sleeping bag seemed dry, just cold, as could be expected given 14
          degrees. It was the hammock though that had the frost on it, other
          than around the mouth. That's why I'm a bit perplexed. I hadn't
          thought about the body heat being lost but that does make perfectly
          good sense.

          Around the face the frost was the worst...but I still had it, ONLY on
          the hammock, all the way down at the feet. The weather was cloudy
          turned clear by morning, no precip overnight. In the several times I
          woke up overnight it was anywhere from partly cloudy to clear. I'm
          not sure what the dew point was. I'm going to have to pay a little
          more attention the next time and see if I notice that being the true
          culprit as it doesn't seem like the breath should be able to make it
          all the way down to the feet.

          Just one strange/stupid curiousity that has come up in my mind. In
          the case of winter camping would you be better off with a cotton
          versus a nylon hammock? Yes, this seems like a real dumb question,
          but think about it for a moment. During the summer months, nylon
          only, I wouldn't consider anything else otherwise, simple because of
          the rain. Winter months though, when you find yourself in a
          situation like I did last night the cotton hammock would have the
          tendency to absorb the moisture instead of the sleeping bag. This
          would keep the sleeping bag drier. There's nothing 'waterproof'
          around you to keep the moisture in so it collects on the sleeping
          bag. Am I wrong on this thinking? Is that why the hammock had the
          frost at the feet but the sleeping bag was dry? The thought just
          came to me as I was typing this.

          MEANT 2B
          GAME '97





          [Non-text portions of this message have been removed]
        • m2b1997
          Are sweat suits designed just like long johns. I never thought they was meant to wick the moisture just to keep the heat in? The idea for the vapor barrier as
          Message 4 of 13 , Jan 6 11:31 AM
            Are sweat suits designed just like long johns. I never thought they
            was meant to wick the moisture just to keep the heat in?

            The idea for the vapor barrier as I see it right now would be to wear
            nothing but keep your clothes between the vapor barrier and the
            sleeping bag, make sure to include a towel. Granted I haven't read
            up on the idea any but this is what makes the most sense right now.
            Your clothes would stay dry and you would stay warm. Just make sure
            you can change clothes in a flash. Sorry about the pun, couldn't
            resist.

            Definitely would have to have it set up as a vapor bag so when you
            went to get out the moisture would stay in the bag. Yeah, just
            thinking.

            Like I said I did 14 degrees last night and it wasn't that bad. Much
            better than 10 degrees on the ground a week or so ago. MUCH BETTER.
            Strangely it seems like it is warmer to stay off the ground than to
            stay on the ground. I've heard you and others talk about how you can
            get so much colder by sleeping in a hammock. I seem thus far to find
            the exact opposite scenario. I guess I need to push the limits to
            change things around.

            MEANT 2B
          • Dave Womble
            ... Ed... seems like this comes up every year about this time, and for good reason. I think you, I, and a lot of winter campers use some type of material to
            Message 5 of 13 , Jan 7 4:40 AM
              --- In hammockcamping@yahoogroups.com, "Ed Speer" <ed@...> wrote:
              >... I'd love to see vapor barriers discussed on this List for I know
              > many of you have tried them with varying results. ...

              Ed... seems like this comes up every year about this time, and for
              good reason. I think you, I, and a lot of winter campers use some
              type of material to breathe through in cold weather. I use a bandanna
              or some type of fleece to breathe through in cold weather to keep from
              getting a sore throat and to limit how much moisture I lose due to
              exhaling. That cuts down on the frost or moisture also.

              I know Ed had things to say about vapor barriers in his book on
              hammock camping. Over the years I have tried to keep an updated
              document on my thoughts about vapor barriers and it is probably a good
              time to re-post that. Here it is:

              My Thoughts on Vapor Barriers... again.

              Vapor barriers aren't that easy to use if you don't understand what is
              going on and they aren't that hard to use if you do. Does that make
              any sense? If it does, you don't need to read any further. If it
              doesn't, then read on and see if this helps.

              I use plastic or silnylon as a vapor barrier between my hammock and my
              SnugFit Underquilt. The suspension system on the SnugFit helps keep
              the vapor barrier against the fabric of the hammock to minimize air
              gaps that would encourage insensible perspiration to condense and
              pool. With the vapor barrier held in place against the underside of
              the hammock fabric, the hammock fabric wicks away any slight buildup
              of insensible perspiration where it can more easily evaporate and I
              usually don't even notice it. I pick when I do that and understand how
              to use it. It is been very effective for me at extending the lower
              temperature range that I can use my underquilt. I would not use a
              vapor barrier when I was using the underquilt in warmer conditions
              because then I would be dealing with sweat and there would be larger
              amounts of sweat/moisture to deal with as the vapor barrier would
              cause me to overheat even more and prevent moisture from sweat from
              passing through the breathable underquilt.

              In general, breathable insulation works best when your insulation is
              getting too warm for you and less breathable insulation works best
              when your insulation is not quite warm enough for you. That has
              everything to do with how, when, and why your body produces sweat (or
              sensible perspiration) and insensible perspiration.

              Your body produces sweat to help cool off at the outer surface of your
              skin with evaporative cooling when you overheat. Your body does not
              produce sweat when you are not overheating... you don't just leak
              water through your skin all the time. When you are not sweating, your
              body can produce insensible perspiration to keep your skin from drying
              out. If your skin is moist enough, or not too dry, your body doesn't
              produce insensible perspiration because it senses that it doesn't need to.

              It takes energy for your body to produce insensible perspiration. When
              you are not overheating and your skin is not producing sweat, a vapor
              barrier will cause your skin to quit producing insensible perspiration
              after some period of time. Your skin quits producing insensible
              perspiration because the vapor barrier creates a high humidity
              environment by trapping the moisture from your previous insensible
              perspiration. When this happens your body does not use energy to
              produce that insensible perspiration anymore and can use that energy
              to help keep you warmer. It a sense, your body becomes a more
              efficient furnace.

              A vapor barrier is not so good when used at the wrong time or when
              used incorrectly. When you are overheating and using a vapor barrier,
              your skin continually produces sweat as a means of cooling off via
              evaporative cooling. The vapor barrier prevents the evaporative
              cooling because the sweat is trapped by the vapor barrier. You just
              keep sweating and moisture can build up. You need to do something to
              keep from overheating because what your body is doing isn't working
              because of the vapor barrier. You need to remove the vapor barrier,
              vent, or remove insulation.

              When you use a vapor barrier with breathable insulation between it and
              your skin, that breathable insulation is subject to getting moist or
              even wet from insensible perspiration. The insensible perspiration
              will initially pass through the breathable insulation and stop when it
              hits the vapor barrier. This continues until the humidity builds up
              enough for skin to quit producing insensible perspiration. But until
              that happens that breathable insulation is going to be getting moist
              too. What you want is a thin wickable sheet of fabric between you and
              the vapor barrier such that it can wick any slight moisture buildup
              away where it can evaporate into the surrounding air. Of course it
              helps for the surrounding air to be able to absorb that moisture
              because if it can't, it won't and you will be clammy.

              And of course, if you use breathable insulation between you and a
              vapor barrier while you are overheating, you will soak that breathable
              insulation with sweat (sensible perspiration). That is bad and that
              happens when people don't understand how and when to use a vapor barrier.

              When closed cell foam pads are used with breathable underquilts in
              hammocks, we get a situation where the overall insulation is greater
              than the sum of the various components making up the insulation. That
              is because closed cell foam pads are also vapor barriers. The vapor
              barrier stops your body from producing insensible perspiration and
              causes the breathable underquilt to provide more apparent insulation
              (although it isn't doing anything different) because your body is now
              operating more efficiently at keeping you warm. If you use a ccf pad
              that provides 20F worth of insulation with a breathable underquilt
              that provides 40F worth of insulation by itself, you will end up with
              more than 20 + 40 = 60F worth of insulation. You might end up with
              70F worth of insulation or more.

              You can also wear a vapor barrier to help stay warmer. You can do it
              selectively for parts of your body or you can do it for your whole
              body (but don't forget you need to breathe). You can use vapor
              barrier liners for sleeping bags or plastic bags over your feet, head
              (as a hat), torso, etc or rain suits. I haven't tried a vapor barrier
              liner for a sleeping bag but have used a rain suit for a vapor barrier
              (even breathable ones work) and used plastic bags over feet, head, and
              torso with success. I always have used thin liner material under them
              with the understanding they would likely get slightly moist from
              insensible perspiration.

              Vapor barriers work well for people that know when and how to use them
              and are often problems or even disasters for people that don't.

              [I am a little conflicted about this particular paragraph. On one
              hand I feel it is important if this write up is going to be used as
              somewhat of a reference for vapor barriers. On the other hand I don't
              want to scare folks about a problem they aren't likely to encounterÂ…
              but here goes.] Understanding vapor barriers, how to use them, when
              to use them, and when not to use them becomes more important the
              colder it gets. I don't have experience in extremely cold
              temperatures but my understanding is that if you use breathable
              insulation at extremely cold temperatures you risk insensible
              perspiration condensing inside the insulation as the dew point
              temperature moves inside the bag itself. Vapor condensing inside the
              bag creates moisture inside the bag and is just as troubling as sweat
              or any other moisture getting inside the bag. When this happens the
              insulation may not dry out at the temperatures you find yourself in
              and can accumulate over the days you are exposed to extremely cold
              temperatures. This can be a troubling phenomenon if it occurs as your
              bag can become increasingly heavier and less efficient. For most of
              us this isn't an issue as I am referring to extremely cold conditions
              and we shouldn't be concerned about the dew point moving inside the
              bag itself at the more moderate cold conditions that most of us camp
              or backpack in. I only mention it because it should be of interest to
              the few individuals that are camping or backpacking in extremely cold
              temperatures.

              Dave Womble
              aka Youngblood AT2000
              designer of the Speer Segmented Pad Extender, SnugFit Underquilt, and
              WinterTarp
              May 13, 2008
              Revised December 1, 2008
            • Hollis Easter
              Dave, I ve been reading stuff about winter mountaineering for a few years now, and your explanation of the theory and practice behind vapor barriers is
              Message 6 of 13 , Jan 7 7:26 AM
                Dave,

                I've been reading stuff about winter mountaineering for a few years now,
                and your explanation of the theory and practice behind vapor barriers is
                probably the most cogent I've read. It matches my own experience with
                them, too.

                Something I might add about vapor barriers is that they're somewhat
                different from other forms of gear in that you need some acquired
                learning before it'll work well for you. The first few times you use a
                VB system, chances are good that you'll get something wrong, whether
                large or small. Maybe you've got too much insulation, so you start
                sweating. Maybe you forget about the VB liner on your sleeping bag, and
                you bring your wet gloves and hat inside it with you, and they're
                sponges in the morning. Maybe... you get the idea.

                The point being that it's never a great idea to bring new forms of gear
                out into the field without practicing at home, but it's an especially
                poor choice if you're just learning to use VB. Sleep out in the backyard
                for a few nights first, where it doesn't matter if you soak your
                insulation or get cold or whatever.

                There's a neat trick I stumbled onto accidentally while testing my
                Hennessy SuperShelter--it'll prove the worth of VB to you. I was
                sleeping out in 20 F weather, with wind. I had the space blanket in VB
                position (pressed up against the hammock body, with insulation OUTSIDE
                it). I didn't quite snug the space blanket up properly the first time,
                though, and there was a spot on my shoulders that didn't have VB.

                I slept really comfortably, and didn't notice any problems (including on
                my shoulders). However, when it came time to pack up, it was easy to
                tell where I'd missed the VB: the open-cell foam was wet enough that I
                could wring some water out of it. It really illustrated the point.

                You could try that on your own by wearing rain pants to bed and then
                looking at the difference in condensation between your legs and torso on
                the inside of the sleeping bag... or you could tape a trash bag to half
                the underside of your hammock. There are lots of ways to mess with it.

                VB is a really useful trick that, like ultralight gear, requires
                knowledge to make it go. I loved your article; have you considered
                sticking it in the files section of the Yahoo group?

                Best,
                Hollis
                On Wed, Jan 07, 2009 at 12:40:36PM -0000, Dave Womble wrote:
                > --- In hammockcamping@yahoogroups.com, "Ed Speer" <ed@...> wrote:
                > >... I'd love to see vapor barriers discussed on this List for I know
                > > many of you have tried them with varying results. ...
                >
                > Ed... seems like this comes up every year about this time, and for
                > good reason. I think you, I, and a lot of winter campers use some
                > type of material to breathe through in cold weather. I use a bandanna
                > or some type of fleece to breathe through in cold weather to keep from
                > getting a sore throat and to limit how much moisture I lose due to
                > exhaling. That cuts down on the frost or moisture also.
                >
                > I know Ed had things to say about vapor barriers in his book on
                > hammock camping. Over the years I have tried to keep an updated
                > document on my thoughts about vapor barriers and it is probably a good
                > time to re-post that. Here it is:
                >
                > My Thoughts on Vapor Barriers... again.
                >
                > Vapor barriers aren't that easy to use if you don't understand what is
                > going on and they aren't that hard to use if you do. Does that make
                > any sense? If it does, you don't need to read any further. If it
                > doesn't, then read on and see if this helps.
                >
                > I use plastic or silnylon as a vapor barrier between my hammock and my
                > SnugFit Underquilt. The suspension system on the SnugFit helps keep
                > the vapor barrier against the fabric of the hammock to minimize air
                > gaps that would encourage insensible perspiration to condense and
                > pool. With the vapor barrier held in place against the underside of
                > the hammock fabric, the hammock fabric wicks away any slight buildup
                > of insensible perspiration where it can more easily evaporate and I
                > usually don't even notice it. I pick when I do that and understand how
                > to use it. It is been very effective for me at extending the lower
                > temperature range that I can use my underquilt. I would not use a
                > vapor barrier when I was using the underquilt in warmer conditions
                > because then I would be dealing with sweat and there would be larger
                > amounts of sweat/moisture to deal with as the vapor barrier would
                > cause me to overheat even more and prevent moisture from sweat from
                > passing through the breathable underquilt.
                >
                > In general, breathable insulation works best when your insulation is
                > getting too warm for you and less breathable insulation works best
                > when your insulation is not quite warm enough for you. That has
                > everything to do with how, when, and why your body produces sweat (or
                > sensible perspiration) and insensible perspiration.
                >
                > Your body produces sweat to help cool off at the outer surface of your
                > skin with evaporative cooling when you overheat. Your body does not
                > produce sweat when you are not overheating... you don't just leak
                > water through your skin all the time. When you are not sweating, your
                > body can produce insensible perspiration to keep your skin from drying
                > out. If your skin is moist enough, or not too dry, your body doesn't
                > produce insensible perspiration because it senses that it doesn't need to.
                >
                > It takes energy for your body to produce insensible perspiration. When
                > you are not overheating and your skin is not producing sweat, a vapor
                > barrier will cause your skin to quit producing insensible perspiration
                > after some period of time. Your skin quits producing insensible
                > perspiration because the vapor barrier creates a high humidity
                > environment by trapping the moisture from your previous insensible
                > perspiration. When this happens your body does not use energy to
                > produce that insensible perspiration anymore and can use that energy
                > to help keep you warmer. It a sense, your body becomes a more
                > efficient furnace.
                >
                > A vapor barrier is not so good when used at the wrong time or when
                > used incorrectly. When you are overheating and using a vapor barrier,
                > your skin continually produces sweat as a means of cooling off via
                > evaporative cooling. The vapor barrier prevents the evaporative
                > cooling because the sweat is trapped by the vapor barrier. You just
                > keep sweating and moisture can build up. You need to do something to
                > keep from overheating because what your body is doing isn't working
                > because of the vapor barrier. You need to remove the vapor barrier,
                > vent, or remove insulation.
                >
                > When you use a vapor barrier with breathable insulation between it and
                > your skin, that breathable insulation is subject to getting moist or
                > even wet from insensible perspiration. The insensible perspiration
                > will initially pass through the breathable insulation and stop when it
                > hits the vapor barrier. This continues until the humidity builds up
                > enough for skin to quit producing insensible perspiration. But until
                > that happens that breathable insulation is going to be getting moist
                > too. What you want is a thin wickable sheet of fabric between you and
                > the vapor barrier such that it can wick any slight moisture buildup
                > away where it can evaporate into the surrounding air. Of course it
                > helps for the surrounding air to be able to absorb that moisture
                > because if it can't, it won't and you will be clammy.
                >
                > And of course, if you use breathable insulation between you and a
                > vapor barrier while you are overheating, you will soak that breathable
                > insulation with sweat (sensible perspiration). That is bad and that
                > happens when people don't understand how and when to use a vapor barrier.
                >
                > When closed cell foam pads are used with breathable underquilts in
                > hammocks, we get a situation where the overall insulation is greater
                > than the sum of the various components making up the insulation. That
                > is because closed cell foam pads are also vapor barriers. The vapor
                > barrier stops your body from producing insensible perspiration and
                > causes the breathable underquilt to provide more apparent insulation
                > (although it isn't doing anything different) because your body is now
                > operating more efficiently at keeping you warm. If you use a ccf pad
                > that provides 20F worth of insulation with a breathable underquilt
                > that provides 40F worth of insulation by itself, you will end up with
                > more than 20 + 40 = 60F worth of insulation. You might end up with
                > 70F worth of insulation or more.
                >
                > You can also wear a vapor barrier to help stay warmer. You can do it
                > selectively for parts of your body or you can do it for your whole
                > body (but don't forget you need to breathe). You can use vapor
                > barrier liners for sleeping bags or plastic bags over your feet, head
                > (as a hat), torso, etc or rain suits. I haven't tried a vapor barrier
                > liner for a sleeping bag but have used a rain suit for a vapor barrier
                > (even breathable ones work) and used plastic bags over feet, head, and
                > torso with success. I always have used thin liner material under them
                > with the understanding they would likely get slightly moist from
                > insensible perspiration.
                >
                > Vapor barriers work well for people that know when and how to use them
                > and are often problems or even disasters for people that don't.
                >
                > [I am a little conflicted about this particular paragraph. On one
                > hand I feel it is important if this write up is going to be used as
                > somewhat of a reference for vapor barriers. On the other hand I don't
                > want to scare folks about a problem they aren't likely to encounter*
                > but here goes.] Understanding vapor barriers, how to use them, when
                > to use them, and when not to use them becomes more important the
                > colder it gets. I don't have experience in extremely cold
                > temperatures but my understanding is that if you use breathable
                > insulation at extremely cold temperatures you risk insensible
                > perspiration condensing inside the insulation as the dew point
                > temperature moves inside the bag itself. Vapor condensing inside the
                > bag creates moisture inside the bag and is just as troubling as sweat
                > or any other moisture getting inside the bag. When this happens the
                > insulation may not dry out at the temperatures you find yourself in
                > and can accumulate over the days you are exposed to extremely cold
                > temperatures. This can be a troubling phenomenon if it occurs as your
                > bag can become increasingly heavier and less efficient. For most of
                > us this isn't an issue as I am referring to extremely cold conditions
                > and we shouldn't be concerned about the dew point moving inside the
                > bag itself at the more moderate cold conditions that most of us camp
                > or backpack in. I only mention it because it should be of interest to
                > the few individuals that are camping or backpacking in extremely cold
                > temperatures.
                >
                > Dave Womble
                > aka Youngblood AT2000
                > designer of the Speer Segmented Pad Extender, SnugFit Underquilt, and
                > WinterTarp
                > May 13, 2008
                > Revised December 1, 2008
                >
                >
              • Ed Speer
                Thanks Dave, your input is most valuable. You & I have discussed vapor barriers many times & I know your understanding comes from experience plus your
                Message 7 of 13 , Jan 7 7:31 AM
                  Thanks Dave, your input is most valuable. You & I have discussed vapor
                  barriers many times & I know your understanding comes from experience plus
                  your analytical mind! Some descriptions of vapor barriers by other people &
                  posted on various sites are confusing or even outright wrong. Thanks for
                  taking the time to write down your thoughts & for sharing them with us.



                  I often say that all outdoor fabrics used for camping exhibit some form of
                  vapor barrier-some fabrics are just better than others. Even no-see-um bug
                  netting is a vapor barrier-just not a very good one. Bug netting does hold
                  in some of your body heat & blocks a bit of cold wind as seen on subfreezing
                  nights. I've even had snow inside my hammock when the bug net trapped some
                  of my expelled breath & allowed the moisture to condense, freeze & fall back
                  on my face as snow. In warmer temps, the bug net can trap enough body heat
                  & moisture to make me uncomfortably warm & clammy. So we all deal with
                  vapor barrier fabrics each time we camp. Dave's observation is correct that
                  we'll be more comfortable when we understand how vapor barriers work & how
                  to add, remove, or vent them when needed as conditions dictate. Sometimes
                  outside temperature & humidity changes during a single night might require
                  the camper to make appropriate changes to maintain comfort. While I wish it
                  was otherwise, no one fabric or vapor barrier is magically perfect for all
                  conditions-so its camper be ware..Ed



                  Moderator, Hammock Camping List

                  Author, Hammock Camping book

                  Editor, Hammock Camping Newsletters

                  Owner, Speer Hammocks Inc



                  From: hammockcamping@yahoogroups.com [mailto:hammockcamping@yahoogroups.com]
                  On Behalf Of Dave Womble
                  Sent: Wednesday, January 07, 2009 7:41 AM
                  To: hammockcamping@yahoogroups.com
                  Subject: Re: [Hammock Camping] Frost free?



                  --- In hammockcamping@yahoogroups.com
                  <mailto:hammockcamping%40yahoogroups.com> , "Ed Speer" <ed@...> wrote:
                  >... I'd love to see vapor barriers discussed on this List for I know
                  > many of you have tried them with varying results. ...

                  Ed... seems like this comes up every year about this time, and for
                  good reason. I think you, I, and a lot of winter campers use some
                  type of material to breathe through in cold weather. I use a bandanna
                  or some type of fleece to breathe through in cold weather to keep from
                  getting a sore throat and to limit how much moisture I lose due to
                  exhaling. That cuts down on the frost or moisture also.

                  I know Ed had things to say about vapor barriers in his book on
                  hammock camping. Over the years I have tried to keep an updated
                  document on my thoughts about vapor barriers and it is probably a good
                  time to re-post that. Here it is:

                  My Thoughts on Vapor Barriers... again.

                  Vapor barriers aren't that easy to use if you don't understand what is
                  going on and they aren't that hard to use if you do. Does that make
                  any sense? If it does, you don't need to read any further. If it
                  doesn't, then read on and see if this helps.

                  I use plastic or silnylon as a vapor barrier between my hammock and my
                  SnugFit Underquilt. The suspension system on the SnugFit helps keep
                  the vapor barrier against the fabric of the hammock to minimize air
                  gaps that would encourage insensible perspiration to condense and
                  pool. With the vapor barrier held in place against the underside of
                  the hammock fabric, the hammock fabric wicks away any slight buildup
                  of insensible perspiration where it can more easily evaporate and I
                  usually don't even notice it. I pick when I do that and understand how
                  to use it. It is been very effective for me at extending the lower
                  temperature range that I can use my underquilt. I would not use a
                  vapor barrier when I was using the underquilt in warmer conditions
                  because then I would be dealing with sweat and there would be larger
                  amounts of sweat/moisture to deal with as the vapor barrier would
                  cause me to overheat even more and prevent moisture from sweat from
                  passing through the breathable underquilt.

                  In general, breathable insulation works best when your insulation is
                  getting too warm for you and less breathable insulation works best
                  when your insulation is not quite warm enough for you. That has
                  everything to do with how, when, and why your body produces sweat (or
                  sensible perspiration) and insensible perspiration.

                  Your body produces sweat to help cool off at the outer surface of your
                  skin with evaporative cooling when you overheat. Your body does not
                  produce sweat when you are not overheating... you don't just leak
                  water through your skin all the time. When you are not sweating, your
                  body can produce insensible perspiration to keep your skin from drying
                  out. If your skin is moist enough, or not too dry, your body doesn't
                  produce insensible perspiration because it senses that it doesn't need to.

                  It takes energy for your body to produce insensible perspiration. When
                  you are not overheating and your skin is not producing sweat, a vapor
                  barrier will cause your skin to quit producing insensible perspiration
                  after some period of time. Your skin quits producing insensible
                  perspiration because the vapor barrier creates a high humidity
                  environment by trapping the moisture from your previous insensible
                  perspiration. When this happens your body does not use energy to
                  produce that insensible perspiration anymore and can use that energy
                  to help keep you warmer. It a sense, your body becomes a more
                  efficient furnace.

                  A vapor barrier is not so good when used at the wrong time or when
                  used incorrectly. When you are overheating and using a vapor barrier,
                  your skin continually produces sweat as a means of cooling off via
                  evaporative cooling. The vapor barrier prevents the evaporative
                  cooling because the sweat is trapped by the vapor barrier. You just
                  keep sweating and moisture can build up. You need to do something to
                  keep from overheating because what your body is doing isn't working
                  because of the vapor barrier. You need to remove the vapor barrier,
                  vent, or remove insulation.

                  When you use a vapor barrier with breathable insulation between it and
                  your skin, that breathable insulation is subject to getting moist or
                  even wet from insensible perspiration. The insensible perspiration
                  will initially pass through the breathable insulation and stop when it
                  hits the vapor barrier. This continues until the humidity builds up
                  enough for skin to quit producing insensible perspiration. But until
                  that happens that breathable insulation is going to be getting moist
                  too. What you want is a thin wickable sheet of fabric between you and
                  the vapor barrier such that it can wick any slight moisture buildup
                  away where it can evaporate into the surrounding air. Of course it
                  helps for the surrounding air to be able to absorb that moisture
                  because if it can't, it won't and you will be clammy.

                  And of course, if you use breathable insulation between you and a
                  vapor barrier while you are overheating, you will soak that breathable
                  insulation with sweat (sensible perspiration). That is bad and that
                  happens when people don't understand how and when to use a vapor barrier.

                  When closed cell foam pads are used with breathable underquilts in
                  hammocks, we get a situation where the overall insulation is greater
                  than the sum of the various components making up the insulation. That
                  is because closed cell foam pads are also vapor barriers. The vapor
                  barrier stops your body from producing insensible perspiration and
                  causes the breathable underquilt to provide more apparent insulation
                  (although it isn't doing anything different) because your body is now
                  operating more efficiently at keeping you warm. If you use a ccf pad
                  that provides 20F worth of insulation with a breathable underquilt
                  that provides 40F worth of insulation by itself, you will end up with
                  more than 20 + 40 = 60F worth of insulation. You might end up with
                  70F worth of insulation or more.

                  You can also wear a vapor barrier to help stay warmer. You can do it
                  selectively for parts of your body or you can do it for your whole
                  body (but don't forget you need to breathe). You can use vapor
                  barrier liners for sleeping bags or plastic bags over your feet, head
                  (as a hat), torso, etc or rain suits. I haven't tried a vapor barrier
                  liner for a sleeping bag but have used a rain suit for a vapor barrier
                  (even breathable ones work) and used plastic bags over feet, head, and
                  torso with success. I always have used thin liner material under them
                  with the understanding they would likely get slightly moist from
                  insensible perspiration.

                  Vapor barriers work well for people that know when and how to use them
                  and are often problems or even disasters for people that don't.

                  [I am a little conflicted about this particular paragraph. On one
                  hand I feel it is important if this write up is going to be used as
                  somewhat of a reference for vapor barriers. On the other hand I don't
                  want to scare folks about a problem they aren't likely to encounter.
                  but here goes.] Understanding vapor barriers, how to use them, when
                  to use them, and when not to use them becomes more important the
                  colder it gets. I don't have experience in extremely cold
                  temperatures but my understanding is that if you use breathable
                  insulation at extremely cold temperatures you risk insensible
                  perspiration condensing inside the insulation as the dew point
                  temperature moves inside the bag itself. Vapor condensing inside the
                  bag creates moisture inside the bag and is just as troubling as sweat
                  or any other moisture getting inside the bag. When this happens the
                  insulation may not dry out at the temperatures you find yourself in
                  and can accumulate over the days you are exposed to extremely cold
                  temperatures. This can be a troubling phenomenon if it occurs as your
                  bag can become increasingly heavier and less efficient. For most of
                  us this isn't an issue as I am referring to extremely cold conditions
                  and we shouldn't be concerned about the dew point moving inside the
                  bag itself at the more moderate cold conditions that most of us camp
                  or backpack in. I only mention it because it should be of interest to
                  the few individuals that are camping or backpacking in extremely cold
                  temperatures.

                  Dave Womble
                  aka Youngblood AT2000
                  designer of the Speer Segmented Pad Extender, SnugFit Underquilt, and
                  WinterTarp
                  May 13, 2008
                  Revised December 1, 2008





                  [Non-text portions of this message have been removed]
                • Ed Speer
                  Hollis, great post! Your advice to try new gear at home before trusting to the outback is right on! Thanks for reminding us of this most critical safety
                  Message 8 of 13 , Jan 7 8:18 AM
                    Hollis, great post! Your advice to try new gear at home before trusting to
                    the outback is right on! Thanks for reminding us of this most critical
                    safety measure.



                    I too have a tale that illustrates just how effective a simple vapor barrier
                    can be. A few winters back, hammocking at home, I awoke in the am very snug
                    & warm, but with heavy frost covering the entire top & sides of my PeaPod
                    (which is a large down insulated sleeping bag that goes completely around my
                    hammock). I was using a thin plastic sheet as a vapor barrier between the
                    bottom of the hammock & inside the PeaPod-but no vapor barrier over the top
                    or sides of me. Apparently some of my body moisture rose during the night,
                    passed thru the insulation on top of me & condensed on the outer shell of
                    the PeaPod where it froze. As an experiment, I removed the plastic sheet
                    without opening the PeaPod more than a few inches. Within 3 minutes the
                    frost on my PeaPod had melted & I began to feel cold seeping into the
                    PeaPod! I think the plastic sheet worked fine, prevented loss of body
                    moisture & warmth on the bottom of the hammock & added noticeable warmth
                    overall. Upon removing the plastic sheet, more of the warm moist air inside
                    my PeaPod was allowed to rise & escape thru the top of the PeaPod quickly
                    melting the frost, even though the outside temp was still well below
                    freezing. At the same time, cold outside air below my hammock could now
                    enter the hammock thru the bottom insulation replacing the warm air inside &
                    making me cold. The plastic sheet apparently disrupted the normal
                    circulation of the warm air around my body inside the PeaPod & kept much of
                    it from rising, escaping thru the top insulation, & being replaced by the
                    inflow of cold outside air from beneath the hammock. So a simple vapor
                    barrier sheet beneath me not only worked on the bottom, but it also worked
                    on the top! I credit my simple 1mil painter's drop cloth plastic sheet (<2
                    oz) with adding 10-200F warmth! .Ed



                    Moderator, Hammock Camping List

                    Author, Hammock Camping book

                    Editor, Hammock Camping Newsletters

                    Owner, Speer Hammocks Inc



                    From: hammockcamping@yahoogroups.com [mailto:hammockcamping@yahoogroups.com]
                    On Behalf Of Hollis Easter
                    Sent: Wednesday, January 07, 2009 10:26 AM
                    To: hammockcamping@yahoogroups.com
                    Subject: Re: [Hammock Camping] Frost free?



                    Dave,

                    I've been reading stuff about winter mountaineering for a few years now,
                    and your explanation of the theory and practice behind vapor barriers is
                    probably the most cogent I've read. It matches my own experience with
                    them, too.

                    Something I might add about vapor barriers is that they're somewhat
                    different from other forms of gear in that you need some acquired
                    learning before it'll work well for you. The first few times you use a
                    VB system, chances are good that you'll get something wrong, whether
                    large or small. Maybe you've got too much insulation, so you start
                    sweating. Maybe you forget about the VB liner on your sleeping bag, and
                    you bring your wet gloves and hat inside it with you, and they're
                    sponges in the morning. Maybe... you get the idea.

                    The point being that it's never a great idea to bring new forms of gear
                    out into the field without practicing at home, but it's an especially
                    poor choice if you're just learning to use VB. Sleep out in the backyard
                    for a few nights first, where it doesn't matter if you soak your
                    insulation or get cold or whatever.

                    There's a neat trick I stumbled onto accidentally while testing my
                    Hennessy SuperShelter--it'll prove the worth of VB to you. I was
                    sleeping out in 20 F weather, with wind. I had the space blanket in VB
                    position (pressed up against the hammock body, with insulation OUTSIDE
                    it). I didn't quite snug the space blanket up properly the first time,
                    though, and there was a spot on my shoulders that didn't have VB.

                    I slept really comfortably, and didn't notice any problems (including on
                    my shoulders). However, when it came time to pack up, it was easy to
                    tell where I'd missed the VB: the open-cell foam was wet enough that I
                    could wring some water out of it. It really illustrated the point.

                    You could try that on your own by wearing rain pants to bed and then
                    looking at the difference in condensation between your legs and torso on
                    the inside of the sleeping bag... or you could tape a trash bag to half
                    the underside of your hammock. There are lots of ways to mess with it.

                    VB is a really useful trick that, like ultralight gear, requires
                    knowledge to make it go. I loved your article; have you considered
                    sticking it in the files section of the Yahoo group?

                    Best,
                    Hollis
                    On Wed, Jan 07, 2009 at 12:40:36PM -0000, Dave Womble wrote:
                    > --- In hammockcamping@yahoogroups.com
                    <mailto:hammockcamping%40yahoogroups.com> , "Ed Speer" <ed@...> wrote:
                    > >... I'd love to see vapor barriers discussed on this List for I know
                    > > many of you have tried them with varying results. ...
                    >
                    > Ed... seems like this comes up every year about this time, and for
                    > good reason. I think you, I, and a lot of winter campers use some
                    > type of material to breathe through in cold weather. I use a bandanna
                    > or some type of fleece to breathe through in cold weather to keep from
                    > getting a sore throat and to limit how much moisture I lose due to
                    > exhaling. That cuts down on the frost or moisture also.
                    >
                    > I know Ed had things to say about vapor barriers in his book on
                    > hammock camping. Over the years I have tried to keep an updated
                    > document on my thoughts about vapor barriers and it is probably a good
                    > time to re-post that. Here it is:
                    >
                    > My Thoughts on Vapor Barriers... again.
                    >
                    > Vapor barriers aren't that easy to use if you don't understand what is
                    > going on and they aren't that hard to use if you do. Does that make
                    > any sense? If it does, you don't need to read any further. If it
                    > doesn't, then read on and see if this helps.
                    >
                    > I use plastic or silnylon as a vapor barrier between my hammock and my
                    > SnugFit Underquilt. The suspension system on the SnugFit helps keep
                    > the vapor barrier against the fabric of the hammock to minimize air
                    > gaps that would encourage insensible perspiration to condense and
                    > pool. With the vapor barrier held in place against the underside of
                    > the hammock fabric, the hammock fabric wicks away any slight buildup
                    > of insensible perspiration where it can more easily evaporate and I
                    > usually don't even notice it. I pick when I do that and understand how
                    > to use it. It is been very effective for me at extending the lower
                    > temperature range that I can use my underquilt. I would not use a
                    > vapor barrier when I was using the underquilt in warmer conditions
                    > because then I would be dealing with sweat and there would be larger
                    > amounts of sweat/moisture to deal with as the vapor barrier would
                    > cause me to overheat even more and prevent moisture from sweat from
                    > passing through the breathable underquilt.
                    >
                    > In general, breathable insulation works best when your insulation is
                    > getting too warm for you and less breathable insulation works best
                    > when your insulation is not quite warm enough for you. That has
                    > everything to do with how, when, and why your body produces sweat (or
                    > sensible perspiration) and insensible perspiration.
                    >
                    > Your body produces sweat to help cool off at the outer surface of your
                    > skin with evaporative cooling when you overheat. Your body does not
                    > produce sweat when you are not overheating... you don't just leak
                    > water through your skin all the time. When you are not sweating, your
                    > body can produce insensible perspiration to keep your skin from drying
                    > out. If your skin is moist enough, or not too dry, your body doesn't
                    > produce insensible perspiration because it senses that it doesn't need to.
                    >
                    > It takes energy for your body to produce insensible perspiration. When
                    > you are not overheating and your skin is not producing sweat, a vapor
                    > barrier will cause your skin to quit producing insensible perspiration
                    > after some period of time. Your skin quits producing insensible
                    > perspiration because the vapor barrier creates a high humidity
                    > environment by trapping the moisture from your previous insensible
                    > perspiration. When this happens your body does not use energy to
                    > produce that insensible perspiration anymore and can use that energy
                    > to help keep you warmer. It a sense, your body becomes a more
                    > efficient furnace.
                    >
                    > A vapor barrier is not so good when used at the wrong time or when
                    > used incorrectly. When you are overheating and using a vapor barrier,
                    > your skin continually produces sweat as a means of cooling off via
                    > evaporative cooling. The vapor barrier prevents the evaporative
                    > cooling because the sweat is trapped by the vapor barrier. You just
                    > keep sweating and moisture can build up. You need to do something to
                    > keep from overheating because what your body is doing isn't working
                    > because of the vapor barrier. You need to remove the vapor barrier,
                    > vent, or remove insulation.
                    >
                    > When you use a vapor barrier with breathable insulation between it and
                    > your skin, that breathable insulation is subject to getting moist or
                    > even wet from insensible perspiration. The insensible perspiration
                    > will initially pass through the breathable insulation and stop when it
                    > hits the vapor barrier. This continues until the humidity builds up
                    > enough for skin to quit producing insensible perspiration. But until
                    > that happens that breathable insulation is going to be getting moist
                    > too. What you want is a thin wickable sheet of fabric between you and
                    > the vapor barrier such that it can wick any slight moisture buildup
                    > away where it can evaporate into the surrounding air. Of course it
                    > helps for the surrounding air to be able to absorb that moisture
                    > because if it can't, it won't and you will be clammy.
                    >
                    > And of course, if you use breathable insulation between you and a
                    > vapor barrier while you are overheating, you will soak that breathable
                    > insulation with sweat (sensible perspiration). That is bad and that
                    > happens when people don't understand how and when to use a vapor barrier.
                    >
                    > When closed cell foam pads are used with breathable underquilts in
                    > hammocks, we get a situation where the overall insulation is greater
                    > than the sum of the various components making up the insulation. That
                    > is because closed cell foam pads are also vapor barriers. The vapor
                    > barrier stops your body from producing insensible perspiration and
                    > causes the breathable underquilt to provide more apparent insulation
                    > (although it isn't doing anything different) because your body is now
                    > operating more efficiently at keeping you warm. If you use a ccf pad
                    > that provides 20F worth of insulation with a breathable underquilt
                    > that provides 40F worth of insulation by itself, you will end up with
                    > more than 20 + 40 = 60F worth of insulation. You might end up with
                    > 70F worth of insulation or more.
                    >
                    > You can also wear a vapor barrier to help stay warmer. You can do it
                    > selectively for parts of your body or you can do it for your whole
                    > body (but don't forget you need to breathe). You can use vapor
                    > barrier liners for sleeping bags or plastic bags over your feet, head
                    > (as a hat), torso, etc or rain suits. I haven't tried a vapor barrier
                    > liner for a sleeping bag but have used a rain suit for a vapor barrier
                    > (even breathable ones work) and used plastic bags over feet, head, and
                    > torso with success. I always have used thin liner material under them
                    > with the understanding they would likely get slightly moist from
                    > insensible perspiration.
                    >
                    > Vapor barriers work well for people that know when and how to use them
                    > and are often problems or even disasters for people that don't.
                    >
                    > [I am a little conflicted about this particular paragraph. On one
                    > hand I feel it is important if this write up is going to be used as
                    > somewhat of a reference for vapor barriers. On the other hand I don't
                    > want to scare folks about a problem they aren't likely to encounter*
                    > but here goes.] Understanding vapor barriers, how to use them, when
                    > to use them, and when not to use them becomes more important the
                    > colder it gets. I don't have experience in extremely cold
                    > temperatures but my understanding is that if you use breathable
                    > insulation at extremely cold temperatures you risk insensible
                    > perspiration condensing inside the insulation as the dew point
                    > temperature moves inside the bag itself. Vapor condensing inside the
                    > bag creates moisture inside the bag and is just as troubling as sweat
                    > or any other moisture getting inside the bag. When this happens the
                    > insulation may not dry out at the temperatures you find yourself in
                    > and can accumulate over the days you are exposed to extremely cold
                    > temperatures. This can be a troubling phenomenon if it occurs as your
                    > bag can become increasingly heavier and less efficient. For most of
                    > us this isn't an issue as I am referring to extremely cold conditions
                    > and we shouldn't be concerned about the dew point moving inside the
                    > bag itself at the more moderate cold conditions that most of us camp
                    > or backpack in. I only mention it because it should be of interest to
                    > the few individuals that are camping or backpacking in extremely cold
                    > temperatures.
                    >
                    > Dave Womble
                    > aka Youngblood AT2000
                    > designer of the Speer Segmented Pad Extender, SnugFit Underquilt, and
                    > WinterTarp
                    > May 13, 2008
                    > Revised December 1, 2008
                    >
                    >





                    [Non-text portions of this message have been removed]
                  • Jeff
                    Re: vapor barriers, I agree with the earlier posts. Here s my story. One night on the Foothills trail I slept in silkweight thermals, a fleece jacket, and my
                    Message 9 of 13 , Jan 7 5:32 PM
                      Re: vapor barriers, I agree with the earlier posts. Here's my
                      story. One night on the Foothills trail I slept in silkweight
                      thermals, a fleece jacket, and my waterproof breathable rain jacket.
                      My fleece was damp in the morning. The next night in similar
                      conditions, I moved the fleece to the outside...silkweights, rain
                      jacket, then fleece. I was much warmer that night and the fleece
                      didn't feel damp. So like Ed says, even though the jacket
                      is "breathable" it's still a pseudo-VB. Makes me want to experiment
                      with VBs more b/c it seems like a very convenient way to substitute
                      knowledge for gear.

                      Of note, Warbonnet Outdoors is making synthetic underquilts and half-
                      underquilts from sil, and underquilt covers to fit over down
                      underquilts. These can act as VBs under the hammock as well.

                      I'm thinking of my next system being a half-underquilt with the inner
                      shell made of sil, a torso-sized CCF pad for under my legs, and
                      possibly a hoodless poncho that can be used as a Garlington Taco to
                      add an extra pocket of dead air space for colder nights. Any
                      thoughts on this setup?

                      Re: the original question, I use a few things to cover my mouth
                      with. Usually it's a Serius brand neofleece facemask. It has little
                      breathe holes over the mouth, and a shaped nosepiece that leaves the
                      nostrils open. Even with the holes it stops a lot of moisture coming
                      out and warms the air a bit when I breathe it.

                      When it's colder, I'll use a balaclava. I've used the both together
                      when it's really cold...not the most comfortable but it's warm.

                      Jeff
                    • Dave Womble
                      ... Done and thanks for the kind words. Dave
                      Message 10 of 13 , Jan 8 3:27 AM
                        --- In hammockcamping@yahoogroups.com, Hollis Easter <easter@...> wrote:

                        >
                        > VB is a really useful trick that, like ultralight gear, requires
                        > knowledge to make it go. I loved your article; have you considered
                        > sticking it in the files section of the Yahoo group?
                        >
                        > Best,
                        > Hollis

                        Done and thanks for the kind words.

                        Dave
                      • Dave Womble
                        ... experience plus ... people & ... Thanks for ... us. ... form of ... no-see-um bug ... does hold ... subfreezing ... trapped some ... fall back ... body
                        Message 11 of 13 , Jan 8 4:04 AM
                          --- In hammockcamping@yahoogroups.com, "Ed Speer" <ed@...> wrote:
                          >
                          > Thanks Dave, your input is most valuable. You & I have discussed vapor
                          > barriers many times & I know your understanding comes from
                          experience plus
                          > your analytical mind! Some descriptions of vapor barriers by other
                          people &
                          > posted on various sites are confusing or even outright wrong.
                          Thanks for
                          > taking the time to write down your thoughts & for sharing them with
                          us.
                          >
                          >
                          >
                          > I often say that all outdoor fabrics used for camping exhibit some
                          form of
                          > vapor barrier-some fabrics are just better than others. Even
                          no-see-um bug
                          > netting is a vapor barrier-just not a very good one. Bug netting
                          does hold
                          > in some of your body heat & blocks a bit of cold wind as seen on
                          subfreezing
                          > nights. I've even had snow inside my hammock when the bug net
                          trapped some
                          > of my expelled breath & allowed the moisture to condense, freeze &
                          fall back
                          > on my face as snow. In warmer temps, the bug net can trap enough
                          body heat
                          > & moisture to make me uncomfortably warm & clammy. So we all deal with
                          > vapor barrier fabrics each time we camp. Dave's observation is
                          correct that
                          > we'll be more comfortable when we understand how vapor barriers work
                          & how
                          > to add, remove, or vent them when needed as conditions dictate.
                          Sometimes
                          > outside temperature & humidity changes during a single night might
                          require
                          > the camper to make appropriate changes to maintain comfort. While I
                          wish it
                          > was otherwise, no one fabric or vapor barrier is magically perfect
                          for all
                          > conditions-so its camper be ware..Ed
                          >
                          >


                          Ed, I can't agree more with you about various fabrics and descriptions
                          like vapor barrier, waterproof, and breathable. Our first inclination
                          is to treat those terms as absolute... if it is a vapor barrier then
                          it is a VAPOR BARRIER and no vapor can pass through it, if it is
                          waterproof then it is WATERPROOF and no water can pass through it, and
                          if it is BREATHABLE then it is breathable and vapor will always pass
                          through it. Turns out, it doesn't always work that way. In fact it
                          doesn't with many of the materials we use- especially fabrics. There
                          are conditions (or requirements, qualifiers, etc.) that we often
                          ignore or don't even hear that affect to what degree something is a
                          vapor barrier, or waterproof, or breathable. Sometimes those little
                          details are inconsequential, other times they make a difference in
                          whether something performs the way we expect.

                          Dave
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