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Re: Underquilt....

Posted: Mon Nov 08, 2010 8:51 pm
by Ridgerunner
Your post..Air is okay as an insulator but I think any leaks around the edges might be a problem.The chances of air leaks is way up there also.Would you really want to get up in the middle of the night,find the leak,patch it,and reinflate it? ..No thanks...
I wouldn't want to have to blow that bag up! :lol:

Re: Underquilt....

Posted: Mon Nov 08, 2010 9:24 pm
by realityguy
Especially at 2am while you're freezing your appendages off... :shock:

:roll:

Re: Underquilt....

Posted: Mon Nov 08, 2010 9:34 pm
by sudden
Ridgerunner wrote:
Your post..Air is okay as an insulator but I think any leaks around the edges might be a problem.The chances of air leaks is way up there also.Would you really want to get up in the middle of the night,find the leak,patch it,and reinflate it? ..No thanks...
I wouldn't want to have to blow that bag up! :lol:
lol
It will be self inflating. Just too hard to explain in words.

Re: Underquilt....

Posted: Mon Nov 08, 2010 9:56 pm
by sudden
Really have to use your imagination for this one, it's all I could find:
Image

Imagine this shape being silnylon, mylar, or tyvex.

Imagine it has no openings except a small bit of fabric at one corner that is the shape of a flat tube?

That tube of fabric would let air in as you stake the bag out to it's final shape. Roll the little tube up or tie it and air in the bag can no longer move. Now you have a big bag of trapped air.

Imagine that shape sewn to the bottom half of a hammock. Extend it and stake it out with elastic lines when you need some insulation or leave it up if you don't.

Re: Underquilt....

Posted: Mon Nov 08, 2010 10:39 pm
by realityguy
I would think the surface mass of your body would be a lot less than the surface mass against the sides of the airbag..however...the sides could be insulated somewhat and your body side of the bag not..transfering the heat from your body to heat the bag.On the other hand,I would think your body may have to work harder later in the evening to maintain heating that extra surface of the airbag..verses a tight thin layer of an UQ against your body itself.Does that make sense? :roll:

Re: Underquilt....

Posted: Mon Nov 08, 2010 10:57 pm
by sudden
realityguy wrote:I would think the surface mass of your body would be a lot less than the surface mass against the sides of the airbag..however...the sides could be insulated somewhat and your body side of the bag not..transfering the heat from your body to heat the bag.On the other hand,I would think your body may have to work harder later in the evening to maintain heating that extra surface of the airbag..verses a tight thin layer of an UQ against your body itself.Does that make sense? :roll:
Makes sense.

I'm not sure if you would lose much heat through the bottom of the hammock down vs. airbag. Heat rises so unless it's being conducted away from the bottom by air movement it might not be very different between the two.

Re: Underquilt....

Posted: Tue Nov 09, 2010 10:40 am
by DarenN
i sewed an UQ from a poly sleeping bag. the first time out with it the overnight temp dropped to about freezing. i froze. i've since gone back to ground. it's warmer.

by the time i get enough insulation to stay warm, the hammock is actually more bulky and heavier than a solo tent.

Re: Underquilt....

Posted: Tue Nov 09, 2010 10:41 am
by realityguy
by the time i get enough insulation to stay warm, the hammock is actually more bulky and heavier than a solo tent.
That's the way I look at it and why I haven't pursued it further...

Re: Underquilt....

Posted: Tue Nov 09, 2010 11:41 am
by JBRanger
You are bang on right about being a ground dweller and being lighter. I've found that out as well. However, I still somehow enjoy hanging. I think it's really more of the "fiddle factor". You have all this stuff that could make a hobby unto itself (hammocking). There's so much to fiddle with to get right and guys seem to enjoy that aspect I've found.

However, if you want to go light. Go to ground. I've slept more comfortably in the air, but can't say I've slept more in a single night in the woods than about 5-6 hours. Whether that's the hammock cold spots, on the ground and something bothering me, or having to do my "business" in the middle of the night. Something always prevents me from getting more sleep. I went to hammocking thinking I'd get more sleep due to comfort. I can't say that that has been the case.

I still enjoy it though! :mrgreen:

Re: Underquilt....

Posted: Tue Nov 09, 2010 3:34 pm
by DarenN
yeah. i'm not knocking hammocks at all. they are comfortable to sleep in. but when the temp starts dropping i'd rather be on the ground. all i need to add to my kit for 0*C is a polartech cap. :lol: