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  1. #11
    WV's Avatar
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    DaleW,
    Great work, beautifully described. Pics are a help, but really not essential when you do such a great write-up.

  2. #12
    Senior Member G.L.P.'s Avatar
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    i dunno about the space blanket and Spinn... your going to have some condensation problems...
    i think you should be fine with just the SPE ..... i wouldn't try to get too crazy
    that and putting that pad under the space blanket in the 2nd hammock i'll call it your going to find that the pad will have a problem forming to your body shape so you might not get the full benefit of the pad .... just a few problems i think you might run into..
    but i say go for it and see what comes of it... never now might work

    you said about liking Synth insulation... have you looked into AHE UQ ...
    he makes some really nice UQ for around $125?
    might be worth looking into
    It puts the Underquilt on it's hammock ... It does this whenever it gets cold

  3. #13
    DaleW's Avatar
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    The Hennessy SuperShelter uses silnylon for the under cover with a space blanket and 5/8" open cell foam for insulation. I don't see any more (or less) opportunity for condensation. Both outer fabrics are not breathable so I would put them at par. I think it is a tossup on using closed cell vs open cell foam in terms of condensation as the layers on either side are waterproof. The open cell foam in the stock SuperShelter is used because it it light and compressible. The real comparison in R-value is between the 5/8" layer of open cell foam vs. the 5mm/3/16" EVA foam I plan to use.

    A "double bubble" windshield pad is about the same thickness as the EVA and there is some reflective quality. Using the loose/crumpled space blanket gives quite a bit of trapped air space and covers a much larger area, plus the radiant qualities.

    In theory, using the space blanket plus the EVA layer gives two layers of trapped air (above and below the space blanket) plus the foam which blocks air and moisture flow as well as reducing heat loss and yet another layer of trapped air between the foam pad and the under cover. Keep in mind that this "sandwich" is very adjustable and the layers aren't packed tight against each other, trapping a lot of air. It can also leak warm air, so a larger outer shell that will seal to the hammock sides is probably needed. On the other hand, a little air leakage might let some moisture escape too.

    What I should be using instead of the foam layer is a layer of Insultex, which has a much higher R-value (R-3) and excellent weight and stowing qualities. When I get my poncho undercover together, I may use an IX/HeatSheet sandwich. $40 for a Molly Mac Gear IX insert sounds good to me.

    The other option for a sandwich is to use the SPE in the hammock with the under cover and space blanket layers. I *know* there would be less condensation than using an SPE alone. I concede that any non-breathable layer between my body and colder air on the other side is going to collect some moisture. The warmer that non-breathable layer is maintained, the less moisture will accumulate.

    All of this depends on the ambient temperature and humidity. I'm looking at use in temperatures greater than 32F and relatively high humidity. The greater the difference in temperature between my body temp and the outside air, the greater the condensation should be, assuming I am not sweating abnormally.

    As it gets colder, the insulating layers get colder and condense more moisture. There must be some breaking point where thick lofty layers become more efficient in terms of cost, weight, compressibility, and moisture issues.

    The one real advantage in using a CCF pad is in a situation where you need to go to ground. That scenario comes to mind with multi-day trips that have large sections above tree line, where time, a storm, or injury would prevent using the hammock kit normally.

  4. #14
    DaleW's Avatar
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    More UnderTaco options

    I cooked up another version today using my modified Grand Trunk Ultralight. The GTUL can really benefit with some windproofing. The fabric breathes very well, which is a good think on a hot summer day and that is probably the best use of an inexpensive, lightweight hammock.

    So I strung it all up and tried the UnderTaco as shown in the previous photos. It worked the same as it did with my Hennessy Expedition Zip. I was using the materials as found and I have to concede that the 86" long fabric of the outer cover is just too short. It will provide coverage from heat to toe, but barely, leaving the tips uncovered and a source of heat loss. I think it is perfectly feasible to make a whipped end cover, but it should be just a bit longer than the main hammock. I have to admit that my UnderTaco gives as much or more coverage as a 3/4 UQ.

    I took a run at it using just a HeatSheet and that works fine for a quick and dirty under cover. In fact, I think it is a technique than everyone should keep in mind. If you ware out and your UQ was soaked, damaged, or lost, making a UC with a space blanket and lining it with spare clothing or forest debris just might save your bacon. The technique could be used with a functional UQ to extend the range and protect for wind and rain. A HeatSheet is 96" x 60", so you can get more coverage than my first attempt. I also tried lining a whipped end space blanket with another loose space blanket and that worked well for a make-do UC too. If you crumple the inner blanket, you get quite a bit of trapped air.

    One think I noticed is that gathering the ends actually wastes quite a bit of the fabric. I strung my GTUL with a ridge line and used that to help hang the UnderTaco, and whipped just the top corners, making more of an envelope. That allowed a lot more coverage on the sides and importantly, around my head and shoulders. I tied the line from the UnderTaco to the ridge line with a tautline hitch. That allowed leaving the cover slack until I got in and then I could just reach up and adjust the tension. That prevented any stress on the sides on the undercover while getting in and I could dial in the space between my backside and the outer fabric.







    For a no-sew rig, that worked pretty good. It does leave a fair gap at the ends. In a pinch, you could duct tape that lower gap in a second. If I were going to sew something like this, a canoe-bow kind of shape could be worked into the profile of the cover and line or shock cord could be run down the sides in channels. A space blanket and/or foam pad could be used inside, as with the SuperShelter.

    I will soon have a poncho version that I collaborated with another HF member on. It will made of silnylon, and 108" x 60". It have a slit head opening, a short collar (no hood), and shock cord/drawstring channels on all four sides. I plan to use it like the Hennessy under cover with a space blanket. I plan on experimenting with alternative insulation. I think it screams for an Insultex blanket. The poncho feature will drop my pack weight by the weight of a rain jacket and I'll get the weather shield feature, a pack cover, and a possible ground shelter out of it too.

  5. #15
    Senior Member G.L.P.'s Avatar
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    dale there are members that had bad problems with condensation using the HH SS me being one of them that is the only reason i pointed that out about your setup
    also the SS uses a OCF pad that will conform to you alot better then a CCF so if you plan on using a CCF pad you might have a few problems with it ... but you might not as well never know till you try
    you might not have any problems with it but just keep an eye out for it(condensation)...
    if you don't run into it just try to regulate the airflow to cut down on it and you should be fine

    this will be nice to test out once the weather gets alittle colder
    i would like to see how low you can take it
    It puts the Underquilt on it's hammock ... It does this whenever it gets cold

  6. #16
    DaleW's Avatar
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    I appreciate the heads up on the condensation issues. It has been there since Day 1 with ground camping, so no surprise.

    I'm going to try the UnderTaco with a HeatSheet and an SPE inside the hammock with a Z-rest pad and 5mm EVA foam side panels. Hopefully, the cover and space blanket will keep enough cold air off the pad and prevent condensation in my sleeping bag. If there is condensation in the cover/space blanket sandwich, it really doesn't matter. Of course I'll try it without the SPE. You can immediately feel the difference when the space blanket is added.

    Another option is to use a Molly Mac Insultex insert. That runs $40 and is light and packs well.
    (http://stores.tttrailgear.com/-strse...ar-/Detail.bok). The IX insert and a space blanket would have to be tested too.

  7. #17
    Senior Member G.L.P.'s Avatar
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    i don't miss my ground days
    last time i slept on the ground was 06 ....
    It puts the Underquilt on it's hammock ... It does this whenever it gets cold

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