Winter walking and condensation on sleeping bag issue
Posted: Fri 22 Jun, 2018 9:12 pm
Hey all,
I'm just a few weeks back from the better part of a five week walk in South Australia on Kangaroo Island and on the Heysen Trail. My intention was to end to end the Heysen Trail in one hit, but the conditions got the better of me and I pulled the pin after about 400kms of walking. I have encountered minor condensation in my previous walks but never anything like I experienced on this walk and I have a few questions/issues I am trying to sort out before I head back out there for another go. I'm hoping the brains trust that is the bushwalkers of Bushwalk Australia might have some suggestions for me.
I currently use a Tarptent Double Rainbow. Condensation wise it's never been a drama and still isn't. I had my first experience of misting on this walk and it took me a moment in the middle of the night to think of Franco's recommendation and start wiping down the interior. That did the trick and apart from not noticing I was squeezing the excess water out of the chux cloth straight into my hiking shoes all was good. But what was a drama was my very damp aka wet sleeping bag, night after night. None of this wetness on my sleeping bag was transferred from the tent as far as I know - I have the Double Rainbow to myself so there's plenty of room to stay away from the walls and apart from that one incidence of misting there was no water falling from the tent roof. I will add I do pitch my tent for maximum ventilation and use the features of the tent (ie rain porch) as much as I can to enhance ventilation as well. If I'm not using the rain porch I will sleep with the fly doors open most nights if weather permits. I'm also usually quite picky about location of campsites but there wasn't the freedom of choice on the Heysen that I'm used to to. There also wasn't much wind or breeze most nights which didn't help.
Anyway on more nights than not I would wake in the morning with moisture on and soaking into my sleeping bag. I've encountered this a little in the past but never to this degree where my bag was actually losing loft and thus warmth as well in the night due to the dampness. Most of the wetness was on my upper chest (I'm assuming it came from the moisture from my breath) but the rest of it was on my leg area with a little moisture on my middle body area as well. At the time I assumed it was the contact of the cold moist night air with the warm air rising through my sleeping bag. I also assumed this is what is referred to as the "dew point". Feel free to set me straight if I"m wrong in these assumptions. I have researched it but am still struggling to get my head around the concepts.
I don't think my wet sleeping bag is anything to do with sweating; on the whole I have to layer like mad to stay warm in bags that would make most people cook. I'm a hopelessly cold sleeper. To illustrate - on the AAWT in Nov/Dec a few years back I used a Mont Franklin with a minimum COMFORT temperature of -12'C (850gram fill of 700+ loft goose down), and that was just right with thermals top and bottom, merino socks, beanie, down jacket and if it approached anything close to/below 0'C I just added my rain jacket and pants which act as like a VPL and was nicely cosy. This walk I took a hoodless sleeping bag that Undercling Mike customed for me which has 600g of 950 fill HyperDRY goose down and taller baffles to match and providing I layered to a similar degree as in the past and used the separate hood combined with a beanie I was fine warmth wise down to as low as 0'C.
But I was starting to feel the cold in the early morning hours as my bag got more damp/wet and lost loft and it was getting more and more difficult to find the time in the short winter days as well as suitable weather (sun and wind) to dry my bag properly every day. Add to that an ear infection that dogged me for the WHOLE five weeks and wasn't getting better and I decided I had had enough of winter walking in South Australia.... for the moment anyway.
So after that long background story (sorry!) what I'm wondering is, in similar damp air/humid conditions:
- Would using something like a very light bivy such as the Montbell Breeze Dry Tec Ul sleeping bag cover help to move the dew point (if that's what it is) out from the surface of my sleeping bag? Ie - if that moisture is coming out of the air and not from my body would it settle on the outside of the bivy bag? Has anyone used a bivy or something similar for this purpose with any success?
- Or... given my Double Rainbow has seen a lot of use and is starting to show some wear and tear what if I replaced it with something like the Tarptent Notch with the semi solid interior - assuming if I used the semi solid interior that might help to raise the overall temperature inside the tent and thus hopefully help to move the dew point further out again perhaps as far as the tent's fly? I don't care about the tent being wet. I do care about keeping my sleeping bag as dry as possible.
I'm keen to get out and do more winter walking but I have to work out how to make it work for me first.
TIA...
I'm just a few weeks back from the better part of a five week walk in South Australia on Kangaroo Island and on the Heysen Trail. My intention was to end to end the Heysen Trail in one hit, but the conditions got the better of me and I pulled the pin after about 400kms of walking. I have encountered minor condensation in my previous walks but never anything like I experienced on this walk and I have a few questions/issues I am trying to sort out before I head back out there for another go. I'm hoping the brains trust that is the bushwalkers of Bushwalk Australia might have some suggestions for me.
I currently use a Tarptent Double Rainbow. Condensation wise it's never been a drama and still isn't. I had my first experience of misting on this walk and it took me a moment in the middle of the night to think of Franco's recommendation and start wiping down the interior. That did the trick and apart from not noticing I was squeezing the excess water out of the chux cloth straight into my hiking shoes all was good. But what was a drama was my very damp aka wet sleeping bag, night after night. None of this wetness on my sleeping bag was transferred from the tent as far as I know - I have the Double Rainbow to myself so there's plenty of room to stay away from the walls and apart from that one incidence of misting there was no water falling from the tent roof. I will add I do pitch my tent for maximum ventilation and use the features of the tent (ie rain porch) as much as I can to enhance ventilation as well. If I'm not using the rain porch I will sleep with the fly doors open most nights if weather permits. I'm also usually quite picky about location of campsites but there wasn't the freedom of choice on the Heysen that I'm used to to. There also wasn't much wind or breeze most nights which didn't help.
Anyway on more nights than not I would wake in the morning with moisture on and soaking into my sleeping bag. I've encountered this a little in the past but never to this degree where my bag was actually losing loft and thus warmth as well in the night due to the dampness. Most of the wetness was on my upper chest (I'm assuming it came from the moisture from my breath) but the rest of it was on my leg area with a little moisture on my middle body area as well. At the time I assumed it was the contact of the cold moist night air with the warm air rising through my sleeping bag. I also assumed this is what is referred to as the "dew point". Feel free to set me straight if I"m wrong in these assumptions. I have researched it but am still struggling to get my head around the concepts.
I don't think my wet sleeping bag is anything to do with sweating; on the whole I have to layer like mad to stay warm in bags that would make most people cook. I'm a hopelessly cold sleeper. To illustrate - on the AAWT in Nov/Dec a few years back I used a Mont Franklin with a minimum COMFORT temperature of -12'C (850gram fill of 700+ loft goose down), and that was just right with thermals top and bottom, merino socks, beanie, down jacket and if it approached anything close to/below 0'C I just added my rain jacket and pants which act as like a VPL and was nicely cosy. This walk I took a hoodless sleeping bag that Undercling Mike customed for me which has 600g of 950 fill HyperDRY goose down and taller baffles to match and providing I layered to a similar degree as in the past and used the separate hood combined with a beanie I was fine warmth wise down to as low as 0'C.
But I was starting to feel the cold in the early morning hours as my bag got more damp/wet and lost loft and it was getting more and more difficult to find the time in the short winter days as well as suitable weather (sun and wind) to dry my bag properly every day. Add to that an ear infection that dogged me for the WHOLE five weeks and wasn't getting better and I decided I had had enough of winter walking in South Australia.... for the moment anyway.
So after that long background story (sorry!) what I'm wondering is, in similar damp air/humid conditions:
- Would using something like a very light bivy such as the Montbell Breeze Dry Tec Ul sleeping bag cover help to move the dew point (if that's what it is) out from the surface of my sleeping bag? Ie - if that moisture is coming out of the air and not from my body would it settle on the outside of the bivy bag? Has anyone used a bivy or something similar for this purpose with any success?
- Or... given my Double Rainbow has seen a lot of use and is starting to show some wear and tear what if I replaced it with something like the Tarptent Notch with the semi solid interior - assuming if I used the semi solid interior that might help to raise the overall temperature inside the tent and thus hopefully help to move the dew point further out again perhaps as far as the tent's fly? I don't care about the tent being wet. I do care about keeping my sleeping bag as dry as possible.
I'm keen to get out and do more winter walking but I have to work out how to make it work for me first.
TIA...