No idea where to put this, so mods just move as needed. It does include a test of under insulation.
OK, this winter I have been testing VBs in various non-severe scenarios. This may be a bit of a waste of bandwidth, as I am awaiting Fronkey's VB report soon. Still, he has been testing for longer trips in severe conditions, what I have been doing is sort of the opposite. But the thing about my testing is: it is pretty much in conditions that conventional wisdom ( including my own way of thinking ) has mostly said: we don't want to use a VB in these conditions. Not cold enough, I'm going to be swamped.
But I have been wanting to retest something I did out in the Olympics a few years back. It was the last night of the trip, and I wanted to see how far I could get through the night using no bag or quilt, just the clothing I had with me any way, and my HHSS. The expected lows were in the high 40s, seems like it ended up being about 49F. So I settled in with:
Original test: ( see post #3 here https://www.hammockforums.net/forum/...ead.php?t=1811 )
1: bottom: HHSS 1 pad + kidney/torso pads, space blanket and undercover
2: For top insulation a light ( or maybe mid? ) weight synthetic long john top and pants, wool socks, and lightweight Polarguard pants ( 8 oz ) and PG hooded top ( 12 or 13 oz) and maybe a cap. Can't remember if I had gloves on. No bag/quilt! My sleeping bag was in a stuff sack inside my HH, as I figured I would need it before day light. I made it until 0700, woke up and thought about getting under the quilt, but what woke me up was my buds breaking camp, so I just got up. But my impression was that I was right at the comfort limit for this set up, 1 or 2 degrees colder and I would have been uncomfortable. So I have been saying that I could get by with nothing but this clothing and the HHSS or other under insulation if confident the lows would not go below 50. And at these temps I would always have clothes like this anyway for hiking and hanging around camp. ( also had separate rain gear )
As above, but
1: no extra kidney/torso pads in the HHSS, just the most basic system.
2:And replace long john top with not much heavier Stephensons Warmlight Fuzzystuff VB shirt. Then same PG jacket from 1st test over that.
3: Add Stephensons VB socks under my wool socks.
4: I have no VB pants. Though it makes no sense to me, many claim that breathable rain gear will function as a VB. So, I put on merino wool long john pants similar in weight to 1st test, TNF UL rain pants over that and the same pants from the 1st test to the outer most layer. So legs same as 1st test but add my supposed to be breathable rain pants to maybe function as a VB.
Summary: same as 1st test, but top LJ replaced with VB shirt, VB socks added under wool socks, and add rain pants under PG pants. And not as much insulation under me. Oh, I used a neck gator, sometimes over my mouth and nose, and can't remember if I used it last time, though I had one. Net in place, but no HHSS OC in either test.
But it was 38F when I went to bed this time, not in the 50s. It was 35F when I quit a few hours later, kept waking up to dogs and maybe coyotes howling, forgot my ear plugs.
At first I thought my feet were going to be cold, but pretty soon they warmed up nicely. When I first dozed off on my back, I was at least adequately warm. When I woke up again at one point I was very warm, even thought about if I needed to vent to keep from sweating, but didn't bother. Turned over on my side, and quickly noticed I was OK but not as warm, certainly not about to overheat. Maybe because the thin insulation in my PG pants/top were flattened somewhat from laying on it and took a while to reloft? Or not as good of a snug fit on the HHSS? Not sure, but I could notice the dif.
So there you go. The only real change was replacing long john tops with a VB shirt and adding VB socks, and I might have had even better results if I could have done the same on my legs. Still can't tell if the WPB rain pants managed to function as a VB to full effect, who knows. maybe? Either way, I was much warmer, considering previously I was def at the limit at ~ 49F. ( oh yeah: had a tarp last time, not this time, so who knows how much that effected things? ) This was about 14F colder. True, I was not there at dawn or for 8+ hours, sleeping deeply with my metabolism going low. So we should give a few degrees to account for that. OTOH, at one point I felt I was on the verge of overheating, so clearly I could have gone a few degrees colder while I was out there before getting to uncomfortable.
At one point I was amazed at how warm I was, considering I have been challenged a few times at temps not a lot colder than this, in more or less the same clothing ( but no VB ), plus using a TQ or bag as TQ!
Oh, not to forget: I had no feeling of dampness above my feet, all felt dry and comfy. My feet felt damp from the beginning and more so after a while. When I came in and stripped off, I really expected to find outright wet on my skin and in the fuzzystuff VB sock liner. But I did not. Whatever was there evaporated so fast that I really could not feel any thing wet on my feet or in the liner. To my surprise, because while laying there my feet felt damp. Very warm, but damp.
I hope this will be useful info for someone. And the more time goes on, the more I am a fan of the VB approach.