Insultex Breathable...really?

[Knotty]

canoebie - That's an application of IX that makes a lot of sense to me. Keep us posted on the experimentation and progress.

[BillyBob58]

This came up in another thread (http://www.hammockforums.net/forum/s...ad.php?t=25059) but I thought it deserved to be discussed on its own.

After using a weathershield made of insultex for just one night (very toasty) I woke to discover that the IX was soaking wet. Reached in and ran my fingers along it and I could see the water on my hands. This pic shows a couple sheets of toilette paper that I patted on the IX. You can see how it blotted up the moisture.
So, the big question is can we really use IX over down insulation? To me it just doesn't seem to breath well enough to use on the cold side (farthest away from body) of an insulation system. It just acted too much like a vapor barrier.

What's been your experience?

So this remains interesting, considering Mac and some others have been using IX over down and OK so far. And I have really been interested in Knotty's condensation issue, as I have been experimenting with IX outside ( sewn to it, very close to it but with an air gap) a layer of CS on a torso UQ. Naturally, condensation concerns me.

One of the factors involved with insulation/breathability is distance from the heat and moisture source. Frankly, I don't see how any material can be breathable when it is quite cold. In the same way that mossy netting ( VERY breathable compared to most fabrics and IX?) can have moisture condense on it when it is cold enough. When vapor hits a surface that is cold enough, it condenses, right?

I remember sleeping bag manufacturers warning about condensation actually occurring before the vapor ever got to the breathable shells, condensation occurring in the insulation when cold enough. So, it didn't matter if the shell was way breathable or not, because the condensation occurred before the vapor ever touched the shell.

Knotty, how far away from you was the surface of the IX sock where the condensation occurred? Was it snugged up close to you or several inches distant from you? Was it one layer of IX plus nylon, or 2 or more layers of IX?

Here is what I am thinking. (First consider that I personally have never had any condensation worth speaking of on a space blanket close to my body, either in the HHSS or PeaPod. (I'm sure I would have had some moisture collecting if I had sweated, but I didn't sweat) In both cases, the SB is much warmer than the insulation that is under it and the SS silnylon HHUC on the outside.

So for people using 2 or more layers of IX, even if it is not breathable at all, wouldn't the layer close to your hammock or skin be relatively warm, with the inner IX layer being insulated by the one or more layers of IX outside of it? So the dew point probably will not be reached on the inside and condensation will not occur.

OTOH, if the IX is actually breathable, I guess vapor might actually be able to get past the inner layer until it contacts the outer cold layers, and condensing in that?

Or, even with multiple layers, but if the surface is far enough away from the sleeper, even the inner layers might be cold enough to cause condensation, maybe?

[Knotty]

BB58 - The IX weathershield is a single layer of IX with a 1.1oz ripstop nylon outer shell. It was hung so that it gently caressed the outside of my JRB Winter Nest. The ends were cinched down to avoid any gaps, just like the Nest.

Had I used a space blanket between me and the Nest, it would have substantially reduced the amount of moist air that could enter the under quilt and there probably wouldn't have been any condensation in the IX weathershield, similar to the Hennessy SuperShelter approach.

A multi-layer IX weathershield used the way my single was, IMO would still have gotten wet. However, a multi-layer IX under quilt, not used over a down UQ, should be fine, since the IX (acting as a quasi-vapor barrier) is at the warm-side of the insulation system. Actually it's also at the cold-side, but that doesn't matter since most of the vapor has been blocked from reaching the cold side.

Breathable materials can be rated but I'm not aware of that ever being done with IX. My guess is it breaths more than silnylon but much much less than gore-tex, event, etc.

My goal in this thread isn't to dis IX. On the contrary it's to better learn what it's properties are thru critical analysis and then know how to best use it.

MacEntyre has done a tremendous job of working with this new material and giving us great products made from it. We're just having a different experience when using it as an outer layer with other insulations.

[BillyBob58]

BB58 - The IX weathershield is a single layer of IX with a 1.1oz ripstop nylon outer shell. It was hung so that it gently caressed the outside of my JRB Winter Nest. The ends were cinched down to avoid any gaps, just like the Nest.

OK, hard to get much closer to the down than that!

Had I used a space blanket between me and the Nest, it would have substantially reduced the amount of moist air that could enter the under quilt and there probably wouldn't have been any condensation in the IX weathershield, similar to the Hennessy SuperShelter approach.

A multi-layer IX weathershield used the way my single was, IMO would still have gotten wet.

Well I was just guessing(or hoping) that, with multi layers of IX in a weather shield, the inner layers would be relatively warmer due to the insulation of the outer layers, so dew point might not have been reached. Or, maybe it would.

However, a multi-layer IX under quilt, not used over a down UQ, should be fine, since the IX (acting as a quasi-vapor barrier) is at the warm-side of the insulation system. Actually it's also at the cold-side, but that doesn't matter since most of the vapor has been blocked from reaching the cold side.

Right, that's what I was thinking.

Breathable materials can be rated but I'm not aware of that ever being done with IX. My guess is it breaths more than silnylon but much much less than gore-tex, event, etc.

My goal in this thread isn't to dis IX. On the contrary it's to better learn what it's properties are thru critical analysis and then know how to best use it.

Understood from the beginning! A bunch of us have been trying to work out the fine points of this wild ( and intriguing) IX stuff!

MacEntyre has done a tremendous job of working with this new material and giving us great products made from it. We're just having a different experience when using it as an outer layer with other insulations.

Understood and ditto that! Looking forward to seeing what your future results are.

[MacEntyre]

...a quasi-vapor barrier

That's a wonderful term!

In case folks are confused, Knotty's excellent explanation is 100% correct.

I have used IX both inside and outside down. It remains a mystery to me that I have not experienced condensation.

- MacEntyre

[Youngblood]

Just for the record, (though I think most people already know) there was no intention of the numbers above to be seen as real percentages.
I was just saying that as waterproofness increases, breathability decreases.
And as breathability increases, waterproofness decreases.
Everybody's goal is to make both better at the same time. But that's were we run into the limitations everyone hopes to improve on, right?

That is how I understand it and why most every well thought out solution has compromises, or situations where it works well and situations where it may not work as well as a different solution might.

[BillyBob58]

That's a wonderful term!

In case folks are confused, Knotty's excellent explanation is 100% correct.

I have used IX both inside and outside down. It remains a mystery to me that I have not experienced condensation.

- MacEntyre

Welcome to the Mysteries of Condensation(or lack thereof) Club!

Much like me with my total lack of condensation with the HHSS with sp.blanket(no condens. either inside the hammock or down inside the UC or on top of the SB except a very few drops), compared to others who have nearly drowned!

Same with a SB used inside a PeaPod, or CCF pads. Though I have not used pads in a hammock very often, I have not yet had any condensation problems. Unlike many others who find them unusable due to this problem.

[canoebie]

knotty et al,

I did a little experimenting with my TQ overhanging and enclosing my hammock last night. (See pics in previous post.) This AM woke up to 30 degrees outside. During the night I had lots of ventilation so did not think I was getting the full effect of the overhead protection. I did not want to completely enclose myself because of condensation, so I hung a small, thin, piece of wool that I use for a pillow over the vent at my head. I checked the temp inside and with 30 outside, it was 58-60 inside and no condensation. I think moisture was able to escape through the wool and at the foot end where there was a slight gap.

I actually had my arms outside of my TQ with short sleeves and I was toasty warm. I had just a wee bit of moisture on the inside, but nothing alarming. Until I can afford a more sophisticated UQ and TQ, I am going to continue to experiment with the IX. I think it has great potential as a cover over my hammock. I had nearly a 30 degree gain just from my body heat. No drafts and warmth. It was real cozy. Sposed to be approaching single digits here in the long term forecast. Anxious to try that.

[scum]

Just my two cents. I tested my diy IX UQ the other night and took it down to the single digits before having to bail because the suspension had stretched to the point that my butt was in the snow (that'll wake you up in a quick hurry). It kept me plenty warm and I had 0 condensation build up on my UQ. My UQ consists of 3 layers of IX (diff cut) and a sewn on outer shell made from a poncho liner. When I took it off in the a.m., it was dry and warm on the inside.

I had also used another poncho liner as an overcover (hung over my ridgeline and tucked between the hammock & UQ). The poncho liner overcover had built up so much condensation that it was a solid sheet of ice by the time I had to bail. I bring this up to point out that there was a condensation issue, but none built up on my UQ. Whats interesting (to me) is that essentially I had poncho liner surrounding my entire setup, but only the top built up the condensation. Makes me think that maybe the IX helped wick away the moisture? Or maybe since it's a 3/4 UQ, condensation was allowed to escape out the uncovered ends? One final note, the overcover was not completely sealed, by nature of it being rectangular and I laid opposite the direction of it's asymmetrical direction (if that makes sense). Essentially, there was a gap at the head and foot so there was some air flow.

Overall, I'm very happy with this IX UQ. I didn't get to prove that it'll handle the single digits unfortunately but it did manage teens w/o issue. Can't complain about that!

[Knotty]

Mac/BB58 - I'm going to guess that some people just put out more moisture than others, so I may wet out a system while you'd stay dry.

canoebie - Those results are amazing. With that kind of temp inside the IX overcover it makes sense that you were condensation free.

scum - In your case the extreme condensation/freeze on the underside of your poncho liner overcover also makes sense. The liner doesn't really provide any insulation, just a wind break and vapor barrier, so the cold surface in the humid environment was ripe for condensation. The poncho liner undercover didn't have any problems because the 3-layer IX UQ kept most of the vapor from reaching it.

EDIT: Just realized scum is talking about a poncho liner, which is insulated and probably somewhat breathable. Duh to me.