undercling-mike wrote:I'll be keen to see what you come up with FootTrack, what material are you using?
I've got some silnylon I'm using for mine. Hopefully it will work out okay!
slparker wrote:I find the discussion on VB clothes for active use somewhat curious. This is only used for extremely cold conditions, from what I have read - and even then Andrew Skurka, for example, emphasises hte need to tailor exertion so as to not sweat too much. Can you imagine what it would be like wearing a VB suit in Australia whilst walking/skiing in anything but a blizzard? I would be comatose with dehydration within the hour. makes perfect sense for static activities, however.
The idea of a VB quilt or bag seems to make perfect sense though. rather than have a VB 'suit' to sleep in, or a VB bag and VB bag cover, what about a sleeping bag/quilt with silnylon instead of standard nylon as the outer?
Hey slparker,
I think the major (?) benefit to using VB clothes rather than a VB sleeping bag liner, relates to donning extra insulation at night. You can wear extra clothes over VB clothes without any issues. However, if you try wearing extra clothes inside a VB sleeping bag liner, they will inevitably wet out. Being able to use these clothes at night means you can take a lighter sleeping bag etc. It also allows you to regulate your heat retention better through layering (if you use a VB sleeping bag liner you can only manipulate your quilt/bag). As others have said, VB clothes may be slightly heavier than a sleeping bag liner but I think this would be very much counterbalanced by the overall weight savings of the system.
In regards to active use, I agree, I can't envisage I will be using them frequently here in Australia for that purpose. However, I think they would be very useful for lower intensity activities (e.g. making meals, setting and packing up) and perhaps whilst starting walking/skiing for the day. By wearing VB clothes when metabolic activity is low (such as in the morning), heat loss can be reduced. Then once moving and when you start feeling more uncomfortable, you can change out of them (which at this time is less of an issue because you can regenerate any lost heat again easily). Using a VB sleeping bag liner, you would lose some heat on changing into clothes in the morning. Of course, if I needed more warmth when walking than a base layer and hardshell, the VB would come out again and I would layer as needed on top of that.
Mike will hopefully correct me if I'm wrong, but silnylon is generally not used for quilt linings for two reasons. Firstly, air needs to be able to pass into a bag easily for it to gain loft (not possible unless it enters VERY slowly through stitch holes if using a waterproof fabric). Secondly, the down becomes almost non-dryable if it wets out via stitch holes and is encased in waterproof fabric. I presume you're talking about silnylon on both the inner and outer of the bag/quilt here...if you only meant the outer, the situation occurs as someone noted above, whereby the moisture can't escape the outer and it ends up condensing inside the bag, reducing loft.
Of late, I have also been taking a gore-tex bivy with me when I go to the snow. I think with my new VB clothes this will be a good system as I can protect my bag from moisture from both the inside and out. It also has the added benefit that I have an emergency shelter with me if I need it, plus a spare set of waterproofs (albeit close fitting ones).