DIY Modding my HH Exped for winter hanging

[OutandBack]

UPDATE:
2nd night testing the summer sleeping bag as an UQ.
Had no trouble staying warm. It wasn't as cold last night only 29F.

As Ron an BillyBob pointed out, I should check for condensation because the SS is waterproof. I did check between the SS and the UQ and
there was condensation. No puddles mind you but enough I could feel it on the SS material and in the summer sleeping bag.

So Ron and BB you were right. Thank you for pointing this out. I might not have caught this issue until it was too late.
IMO, This could be a real problem on a multi day outing in cold weather.

IF a vapor barrier was installed above my UQ. Wouldn't that just move the condensation problem up the bottom of my sleeping bag?

For right now, this mod is a bust for me. Using the HH SS to hold a summer sleeping bag in place of a UQ was not successful.
To make this work properly the 2nd layer needs to be breathable.

[BillyBob58]

Last night I tried something similar, using a KAQ primaloft underquilt inside a SS. Conditions were as bad as can be for condensation with temps starting in the high 20's and then rising into the 30's with heavy rain and high humidity. By morning my KAQ was soaked, but I did stay warm. Had I used a down underquilt it would have been a very uncomfortable night.

This is a very interesting thread for me. First of all, some great mods. Snaps to hold whatever insulation in place! What a great idea. And of course, continuiing discussion about why condensation sometimes still occurs on the other side of a VB. And the mystery of why some of us, even in very humid climes, have never experienced any condensation problems. But i missed commenting on an important point earlier: synthetic insulations's supposedly "warm when wet" properties. Here is Knotty telling us that his quilt was SOAKED, but he was still warm in the 20s to 30s! (BTW, what is the rating of that quilt when dry?) I don't know what OutandBack's summer bag UQ was: down or synthetic? Any way, this takes me back to the tests I did with my Polarguard jacket, soaking it before going for a hike in a cold light rain for a mile or so. Only to stay warm and find it bone dry at the end of the walk.

Many are of the opinion that neither down nor synthetics are worth a hoot when wet. I think I disagree. True, synthetic will work much better if dry. But I think there are still significant insulation available even when wet. Plus, they tend to dry quickly.

UPDATE:
2nd night testing the summer sleeping bag as an UQ.
Had no trouble staying warm. It wasn't as cold last night only 29F.

As Ron an BillyBob pointed out, I should check for condensation because the SS is waterproof. I did check between the SS and the UQ and
there was condensation. No puddles mind you but enough I could feel it on the SS material and in the summer sleeping bag.

So Ron and BB you were right. Thank you for pointing this out. I might not have caught this issue until it was too late.
IMO, This could be a real problem on a multi day outing in cold weather.
.................................................. .........................

For right now, this mod is a bust for me. Using the HH SS to hold a summer sleeping bag in place of a UQ was not successful.
To make this work properly the 2nd layer needs to be breathable.

I wouldn't call this a total bust. Good grief, even with no doubt some condensation the first night, you were still warm at 14F! Then did you leave it in the system for a day and use it another night and still warm?

Sounds to me like you are on to a good system! You just need to take the standard Hennessy recommended HHSS precaution: add a 2 oz, $3 space blanket(SB) on top of all under insulation. Not only SHOULD that keep your insulation bone dry, but it will add significant warmth. Make sure the entire bag is covered. I even try to have my sp.bl. close to the edges- or even draped over- the edges of the HH UC. ( my HH pad and foot of my bag was soaked once, on a humid night when I did not use my SB)

IF a vapor barrier was installed above my UQ. Wouldn't that just move the condensation problem up the bottom of my sleeping bag?

You can see the conflicting experience in the previous posts. When I have used a space blanket either directly under my hammock and on top of my insulation, I have never had any condensation UNDER the space blanket, or in the under cover or in my Pea Pod, or in the hammock. The worst I have seen is a very few drops right on top of my space blanket. That is my experience, and there are some others who have used this system with no problems.

At the other extreme, you have read Knotty's experience in the above post. ( Knotty, did you have any condensation inside the hammock, or just down in the UQ?) He is not the only one to have such a result. The great mystery to me is: why some have such problems and others never do.

But I would think it would be worth trying a cheap space blanket or VB ( just make sure whatever you use is water proof) on top of the under insulation and see if that keeps your summer bag dry.

BTW, is your summer bag down or synthetic?

[BillyBob58]

These folks http://warmlite.com/vapor-barrier make VB systems for down bags. They say :

With VB keeping water vapor and wet sweat out of your sleeping bag and clothes, you can use ANY fabric, ANY insulation without concern for wickability, and can use ANY exterior wind breaker without concern for “breathability”.

So what is the difference? Why don't they have condensation problems in their down bags, even if a water proof non-breathable exterior is used, as long as an inner VB is used first? What is the variable that cuases some folks to experience condensation in an HH SS UC, even when they have a VB between their body and the insulation and UC?

[OutandBack]

BTW, is your summer bag down or synthetic?

The summer bag is synthetic.

I really hate Space Blankets(noisy, hard to fold or layout, tears) and would prefer to not use one. I might try a VB of 3/8" CCF cut just larger than the sleeping bag.

[Knotty]

BB58 - To answer your question, I only had condensation in the KAQ and SS. The hammock and top vapor barrier were dry.

Also, I agree about synth doing better when wet compared to down. Down collapses and clumps when wet, trashing it's inulsative qualities. I would imagine that many synthetics just get wet but don't collapse. They won't insulate as well as when dry but still are useful.

[JayS]

UPDATE: IF a vapor barrier was installed above my UQ. Wouldn't that just move the condensation problem up the bottom of my sleeping bag?

Not necessarily - the moist vapor that is now above the VB is also above your insulation (UQ) and is warm, most likely above the dew point temperature. And because of the VB and the warmth, your insensible perspiration (or is it your sensible perspiration??) may slow down considerably.

I really hate Space Blankets(noisy, hard to fold or layout, tears) and would prefer to not use one. I might try a VB of 3/8" CCF cut just larger than the sleeping bag.

OutandBack,
I thought of space blankets the way you do until I broke down one chilly night and used one between my hammock and UQ. Once in place, it was very quiet. I have used it about 7 or 8 times and it hasn't torn. And folding is not hard as long as you're not trying to fold it back to its original size - I use a quart ziplock to store it now. Just remember it doesn't let air through and fold it so it doesn't trap air and you'll be fine.

My last night using a space blanket this way was with knotty the night before he used the KAQ and SuperShelter (i.e. last Friday night) and I was snug, and quiet, to 18*F.

[BillyBob58]

The summer bag is synthetic.

I really hate Space Blankets(noisy, hard to fold or layout, tears) and would prefer to not use one. I might try a VB of 3/8" CCF cut just larger than the sleeping bag.

That paid would serve as a VB, but it sure would cost more, weigh more and take up a lot more pack volume than a SB. (unless, of course, you are carrying the pad anyway for whatever reason) But, my SB, at least on top of my SS pad, curves up around my shoulders, for a more complete vapor block and added warmth. Like JayS said, I NEVER hear mine after it is installed in the SS.

BB58 - To answer your question, I only had condensation in the KAQ and SS. The hammock and top vapor barrier were dry.

OK, good to know. Similar to my experience, on top anyway. But quite dif with the condensation below. Do you have any theories on why that happened? Your SB was, I'm sure, waterproof? ( I doubt any are made that are not WP, but you never know)

Also, I agree about synth doing better when wet compared to down. Down collapses and clumps when wet, trashing it's inulsative qualities. I would imagine that many synthetics just get wet but don't collapse. They won't insulate as well as when dry but still are useful.

Yes, I really don't think there is much doubt. I was kind of waiting to see if OutandBack's bag is syn, and it is. So he used it two nights running, apparently not setting it out to dry. No doubt collecting at least some condensation both nights in the SS UC, and was still warm as low as 14. You used a "soaked" Primaloft quilt and stayed warm from ~20-30. I think that all speaks for itself. Combined with my experiments with soaked Polarguard, I come to the conclusion that there is at least some amount of truth to the "warm when wet" hype.

[OutandBack]

I wouldn't call this a total bust. Good grief, even with no doubt some condensation the first night, you were still warm at 14F! Then did you leave it in the system for a day and use it another night and still warm?

Sounds to me like you are on to a good system! You just need to take the standard Hennessy recommended HHSS precaution: add a 2 oz, $3 space blanket(SB) on top of all under insulation. Not only SHOULD that keep your insulation bone dry, but it will add significant warmth. Make sure the entire bag is covered. I even try to have my sp.bl. close to the edges- or even draped over- the edges of the HH UC. ( my HH pad and foot of my bag was soaked once, on a humid night when I did not use my SB) -BillyBob58

Thanks for the pep talk BillyBob. You are right this no cost DIY UQ experiment did keep me warm for two nights with only minor condensation. I will give the SB a try.
I was thinking the CCF would be better because it would work as a VB and additional insulation.
I forgot about the additional weight. Thanks for reminding me about that.
The winter weather in Colorado has been on the warm side. The next cold front that comes thru I will get back out there.


Bob and Ron, I also agree syn bags do keep you warmer than down when wet and syn drys much faster.
I typically use syn bags when I'm Kayak camping or know I will be around water (rivers, heavy rain) and there is a chance my bedroll will get wet.
I use a down SB mostly for winter camping.

Not necessarily - the moist vapor that is now above the VB is also above your insulation (UQ) and is warm, most likely above the dew point temperature. And because of the VB and the warmth, your insensible perspiration (or is it your sensible perspiration??) may slow down considerably. -JayS

Thanks Jay, this gives me hope for my next test using a SB or CCF pad.

[Knotty]

I used a down bag inside an IX weathershield on the first night of last weekend's hang. No space blanket. Previous experience told me to expect condensation. That night I did start to feel a little chilled underneath as the night wore on. Sure enough the weathershield was very wet and you could see dampness in the down. More info for the wet down vs. synthetic discussion.

[BillyBob58]

I used a down bag inside an IX weathershield on the first night of last weekend's hang. No space blanket. Previous experience told me to expect condensation. That night I did start to feel a little chilled underneath as the night wore on. Sure enough the weathershield was very wet and you could see dampness in the down. More info for the wet down vs. synthetic discussion.

I guess that last part ( wet syn vs down) is not exactly the OP's original subject matter ( trying to avoid hijack). But then again, the original set up did lead to wet insulation, so..........

I hope the sp.bl. stops Outandback's condensation problems well enough. Still pondering why Knotty had the soaked KAQ despite a SB.