I was fortunate to get in on the group buy of Insultex. This is my tenth bridge hammock that I have made. The use of Insultex insulation is what sets this hammock apart from previous versions. Also, using a double layer of fabric through the entire hammock was a first for me. The size and cut of the hammock were designs aspects that have been unchanged from previous hammocks. So, here is the report covering each componant:
Spreaders: This narrow bridge styled hammock utilizes a 30" JRB spreader bar at the head, and an 18" Quest spreader bar at the foot. The Quest pole nests inside one of the JRB poles, so they stow away fairly compactly. They don't detract much from the usable volume of the pack. The poles easily share one of the side mesh pockets of my pack. A water bottle or other pocket contents can easily be added or retrieved without interference with the poles. TeeDee makes a good argument for using other materials for spreader bars instead, I remain open to that idea for next time.Insul_hammock_empty.JPG
Hammock Body Pattern: Both pieces of fabric are 104" in length after hemming. This length is designed for a person 5' 10". The finished fabric widths are 42" at the head spreader, 26" at the narrowest point in the middle, and 31" at the foot spreader. The spreader bars are 60" apart. I tapered the cut of the fabric that extends 18" beyond the head spreader bar. I angled it about 30 degrees in from it's 44" width. The suspension triangle comes in at nearly 45 degrees, but when I tapered the fabric 45 degrees on a previous hammock, it seemed to lift my head too much. I had the opposite problem when I didn't taper the material at all, the back of the head seemed unsupported. So I sort of split the difference, and got a very good result. Similarly, I tapered the fabric that extends 26" past the foot spreader, but at a slightly lesser degree, going from 32" to 24" in width. The side cuts were measured at 6", but somehow only resulted in 5 1/2".
End Caps: The end caps were formed by folding the fabric up at the ends and cutting away the excess in each corner. It's like a large curved dart pulling together 8" of fabric along each edge of the corners at the head end (6" at foot corners), and the tucked fabric extends 10" inwards equidistant towards the center of the hammock body. This excess was cut and the raw edges were rolled and hemmed. It was then reinforced with grosgrain ribbon at these seams. Insul_hammock_head_end.JPG This has become my favorite way of doing the end caps. The advantage seems to be more usable space within the hammock for the amount of fabric used. This is due to the way the hammock bottom curves up to form the walls at the ends. The disadvantage is that it results in more wasted fabric than if the endcaps were cut out separately.Insul_hammock_foot_end.JPG
Hammock Material: The inside material is a 1.26 polyester fabric. The outside layer is 1.1 ripstop nylon. Both layers are used in the entire hammock body, including end caps. They each have 1/2" heavy nylon webbing along the lateral edges. The top and bottom layer were sewn together above the shoulder and below the knee, but left separate between those points.
Insulation Material: Between the polyester inner shell and the nylon outer shell are two layers of Insultex. These have been permanently installed using 3/8" elastic webbing. This was done to address the shell fabric's stretch and the Insultex material's lack of stretch. There are a total of ten attachment points to the hammock body with the elastic webbing. Three are situated at the head, five extend down from the foot end, and the other four attach near the shoulders and knees on each side. The Insultex has been cut basically in the shape of a tapered foam pad, except it extends 3" on the long ends and 4" to 5" out from each side. I sewed 1" polyester ribbon along each to hold the two layers of Insultex together and to prevent tearing of the fragile material. And I cut a slight curve to coincide with the lateral arcs of the fabric, ending up with 26" at the narrowest part of the middle of the hammock. The Insultex extends up around my head for at least a couple inches beyond where my head makes contact. A 10" wide little end panel has been added to the bottom wall of the footbox. This is in case I pitch the hammock too low at the foot end resulting in direct contact of the fabric with the bottoms of the feet. Although, when hung properly, there is room to flex my feet without touching the bottom wall of the footbox.
Weight: The weight of the insulated hammock body is 17 ounces (this model doesn't have a bugnet). Pole weight is 6.2 ounces. I add to this my (Spinnaker)tarp weighing 9 ounces including 4 (MSR Needle) stakes, and my 4 ounce treestrap configuration. This gives me a packed weight of just over 2 1/4 lbs.
Pad Use: A panel of 1.1 nylon has been sewn on to the bottom of the Insultex layer at the head and the foot. They are accessible through either side where the top and bottom fabric layers have been left separate from shoulders to knee. These panels form pockets that will hold a full length tapered inflatable pad. I plan to use this to supplement the Insultex insulation for temperatures below 50 degrees. The POE Insul-Mat at 19 ounces is my current top choice. I expect that the combination of this pad with the Insultex should keep me warm to the low 20's or lower. That is if the Insultex insulation doesn't become too compressed due to the way I constructed it. I base this estimate on the observation that the pad by itself has only been comfortable into the upper 30's (when tested with another hammock). And the Insultex by itself will get me down to 50 degrees comfortably.
Full Disclosure: I should add that I don't have the stretch ratio of the shell and Insultex worked out in any scientific way- just guesswork. Due to the coolness I experienced on my back during a night with a low of 46 degrees, I think it is likely that the Insultex is stretched too tight through there. I will look at the possibility of fitting it with longer elastic webbing at the shoulder attachment, but I will do more testing before I decide. It might also be due to the outer shell fitting too close to the inner shell. I was hoping the inner shell would stretch less than the outer shell, being polyester as opposed to nylon. And further hoped that difference in stretch rather than size would be effective in keeping the Insulation from getting compressed. I may have misjudged this.
Musings: This has been possibly my most comfortable hammock yet. So far, I have only slept in this particular hammock without an inflatable pad. In my past experiences with other hammocks, the use of the pad increases my comfort even more. This is due to the side spreading action of the pad when inflated really full, it keeps the occupant from nearly all contact with hammock sides. The spreading effect gained by using a fully inflated pad also has the effect of lifting the center of gravity. I REALLY like how the lifting up feeling counteracts the sinking in feeling, resulting in a near floating feeling. But this can also give a "tippy" feeling when the occupant is not well centered in the hammock. This has not posed any kind of problem for me, but it is something I can notice as a comparison when testing different configurations. The relatively small curve cuts (5 1/2") do seem to require a tighter hang to achieve the most comfort. This tighter hang is also a factor in the high center of gravity tippy feeling. But again, I don't experience this as a problem. That being said, I reserve the right to change my mind about how high my center of gravity should be if further testing gives me new insights.
sideview_no_pad.JPG
In this photo, I am laying in the hammock without a pad. You can see how far the Insultex extends up the sides. It seems like adequate coverage to me.
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