Nice writeup, thank you
Nice writeup, thank you
I've never played with a VBL. Sounds clammy and wet. But I see the point and purpose. In the right conditions it would make sense.
Dejoha, excellent work as usual.
How about a tyvek suit? Or is tyvek considered too breathable? (never breathed well when I wore one)
Ambulo tua ambulo.
tyvek
Exactly what I was thinking.
In my type of winter camping, usually 3 days 2 nights I have never experienced a down failure from excessive moisture build up. Maybe I don't sweat very much when sleeping.
If I was planning an extended winter stay I think I would try the tyvek suit.
After reading this, I had to go out and try a ghetto VB solution. My GT ATHH that I use in Winter is PU coated, so the entire hammock is a VB between me and my lower insulation. I took a kitchen trash bag and punched a head hole and arms holes into it. Under the kitchen bag, I wore a thin synthetic t-shirt. Over it, I wore a fleece top. On my leg, I wore Smartwool long underwear and my rain pants.
For top insulation, I used one of the sportmans' reflective blankets and a thin CS BPL TQ. Headwear was just a neofleece balaclave and a BPL hood.
Long story short, it was in the upper 30's F when I turned in, and I was roasting. Fast forward to 4 am ( I must have slept through Santa's visit) and I was cool and clammy all over. Somehow, there was quite a bit of condensation under the space blanket I had on top even with all of the VB stuff. My guess is that since I had neglected to put bags on my feet and my arms were not enclosed in a VB, I probably did not do a very good VB job. On top of that, temps only fell into the upper 20's.
FWIW, that BPL TQ usually only gets me into the lower 50's before I get cold. So by all rights, the VB did buy me 20 degrees more than I would have normally had.
I've ordered one of the WarmLite VB shirts. I figure closing up the arms in addition to the torso will make for better results. I also think the colder and drier it is the more you'll get out of it. (Upper 20's is probably on the upper end of usefulness. Colder would be better.)
All in all, it's a pretty good solution to not only stay warm and remain better hydrated but also keep your insulation from wetting as the dew point moves closer to your body (read inside you insulation) in colder temps.
Yeah, that suit is cheap and pretty convenient unless you made a bag liner out of it but you'd have to seal the edge with a zipper so getting in and out is a pain.
Tyvek, Gore-Tex and eVent do breath too much for a good VB. I've gone to bed in a wet merino top and a breathable jacket over top to awaken to a dry merino top. I've also dried socks this way. The down side (no pun intended) is that the moisture from the socks and top escaped not only the jacket but also into my down. If the dew point is high enough, that moisture will pass through the down and escape. If the dew point is lower, that moisture becomes trapped in the down.
I think VB is best probably in the teens or below. Above that, the dew point tends to be on the outside of your insulation. Teens and below will put the dew point closer to your body which can be inside your insulation.
Looks like spectacular success to me, way warmer than you would have been normally, eh? And all of that moisture that condensed on the refl. blanket: curious as to why it condensed there rather than all inside the garbage bags? Maybe your theory why is correct. And what kind of rain gear, maybe it did not stop the vapor?
But that always leaves the question: had it not condensed on the ref. blanket, would it have condensed some where else? Maybe in the outer layers of the insulation? Also, had it not condensed on the ref. blanket, would it have then provided some evaporative cooling to your skin and/or insulation?
I always expect to be clammy, though hopefully not cool, when using VBs(exception: space blanket in a HHSS or PeaPod). This tells me it is working as planned. And it only gets damp, and nothing more unless I over heat and actually sweat. This clamminess freaked me out the 1st few times I felt it, I thought I was wet. And I was, but only my skin and innermost synthetic layer. But this dampness was blocked from causing evaporation and cooling. This is not the best feeling in the world, but is for sure warmer. So, wet(clammy, damp) but warmer. I always try to wear the absolutely thinnest layer I have between skin and VB.
For an impressive demonstration of the effectiveness of the bodies evaporative cooling ability, try a test. Put a vapor barrior on in some cold temps. Leave on a while, and avoid sweating. Then, snatch that little thin layer of WP nylon off of your torso or feet. Get ready to feel a rapid and very noticeable drop in skin temp! It will get your attention for however long it takes that dampness to evaporate. It will take a significant amount of body heat with it as it evaporates.
I ahd a buddy whose feet were freezing while fishing in winter, one Nov in the snowy AZ mountains. He borrowed my VB socks, put them under his thick socks. Within a short time, his feet were warm.
I've been thinking about one of those Warmlite shirts and pants for a long time. Please let me know how you like it(or why you don't!
BillyBob58, I actually was pretty impressed that a 13 oz synthetic TQ and a sportman's blanket could keep me fairly comfortable into the upper 20's. (The pants I used were Mountain Hardware Conduit..breathable but not all that breathable.) The kitchen bag with a head hole and arm holes probably did not make that great of a seal around my torso. That and forgetting to do anything VB on my feet probably caused the condensation. (If I had to guess, there were maybe 3-4 ounces on the inside of the top space blanket.)
While some just go with minimal clothing and a VB bag liner, I prefer VB clothing. With VB clothing, I should get a better seal and I can still put other items of clothing packed on over top of the VB layer if needed. I know I can pile my clothing around the outside of a VB bag, but wearing a fleece jacket is probably going to insulate more than just piling it on my TQ.
Oh, I did "place an order" with Warmlite, but for them that just means they will call or email you to discuss what it is that you actually wanted. I think the socks and shirt would be the best option from them. I figure I can get surgical gloves for hand VB, and those rain pants are probably VB enough to reduce the amount of insensible perspiration from my legs.
I really do like the advantages of VB in Winter conditions. Not having to worry about keeping you insulation dry from the inside might allow the use of a non-breathable weathershield on top of a TQ for even better moisture control. Of course a "bonus" 20 degrees of insulation is not too shabby either!
I agree, high 20s from a 13 oz syn TQ and extra 20 plus degrees over normal is not too shabby, not to forget dry insulation and all for a small amount of weight. And if rain gear provides the VB, the extra weight is zero.
Ever tried a VB inside the bottom of a Pea Pod? Or what about that Warmlight VB clothing serving as a VB for top and bottom in a PeaPod?`
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