Hey guys, I need to make an underquilt for my BB but I only need it for summer temps here in Cali. So my question is whether or not silnylon would work as an underquilts outer layer? I realize that the concensus is that sil is not breathable, but I would think that would be optimal considering I want to block wind.
Humidity in Northern California isn't much of a problem, especially at altitude during the night, and since the underquilt is under the hammock, wouldn't there be minimal condensation anyways?
I have an Idea to use the sil as an outer layer and sew it to a material that will not only provide warmth, but is extremely lightweight. I won't mention what it is because I am not yet sure if the material can be sewn; making my idea moot.
Has anybody tried this in similar conditions with either success or failure? I really could use your feedback on the best material to use as you all have vastly more knowledge than myself, and I want a better understanding of my materials before I invest in them.
Thank you in advance for any insight.
I would recommend a landscape fabric UQ. I made one in spring, and it has worked great as a warm weather UQ. Sew a layer of breathable ripstop on the outside, and use the landscape fabric as an inner liner. Very inexpensive and it is just the ticket down to ~60*. I never got around to the trip report with it, but I use it almost every night in my backyard, and I did use it on the NCT trip.
That landscape fabric was a good idea (i read your thread when you posted it) but as for the ripstop, I still want to know if silnylon would be a viable option? Hasn't anybody tried it in an underquilt?
I've tried a variety of non-breathable materials as a UQ, but not sil. For the most part, all non-breathable materials I have tried have caused back sweating or condensation. Sewn to some kind of insulation, it would probably act similar to a non-breathable pad, just a lot more comfortable in the hammock.:D If you don't sweat on a pad, you would probably be ok with a sil UQ. I can't use a non-breathable material for a UQ or even a pad most of the time. I just get a clammy back.
well that is helpfull. What is the humidity and temp at night like where you normally hike? I would presume pretty cold.
Summer time, humidity is normally between 50-80%. Temps this week have been in the 50's and 60's at night. That's pretty normal for this neck of the woods.
that's about what it is at alti in cali. I like your landscape fabric, and thanks for the help, I think I'm gonna try the sil as I got a line right now on .07oz per sq yard for less than $10. I'll post my findings.
the problem is water vapor coming off of you goes into the quilt and can't evaporate to the outside because of the sil. is there insulation in this thing by the way? if not you might be ok, but i think any insulation could get wet from body vapor because the moisture couldn't pass through.
i have done some synthetic insulation quilts with sil shells, but both shells (inside and outside) were both sil, so body vapor couldn't get to the insulation in the first place. those worked well and did seem to cut wind better than dwr.
check the fabric you got. if it's really 0.7 oz/yd i doubt it's sil, never seen sil less than 1.3, that's about half the weight. you're talking cuben fiber weight at 0.7 so i'd say you've got something else.
I think I read the weight wrong, I'm still pretty new to this and I believe you're right. I think now looking at it again, it's 1.3 +/- .07oz. This is my own ignorance, but to me that's still quite lite. There is no absorbant insulation at all... I guess I just need to experiment and post my results. Thanks Warbonnetguy and Fin for your help
I've heard that those quilts were excellent, btw.
Originally Posted by warbonnetguy
Yeah, that's what I was implying/trying to say as well. Both sides would need to be sil, and then it would act similar to a non-breathable pad, just conforming to the hammock body instead of the hammock body conforming to it. And the fact that it is outside the hammock.;)