Hi All -- I'm new, and of course, I have come for advice.
I've been doing a few nights of hammock camping every year for awhile using a pre-assym. HH that I like a lot. Mostly I do bicycle camping in the Cascade mountains (prefer logging road adventures). That means it gets pretty cold at night. Usually in the 40s but sometimes lower. I currently use a 3/4 length therma-rest under my torso and wad my jacket and some of my clothes for insulation under my legs, but that's sub-optimal for all the reasons you already know (too narrow, shifts when I move, etc.)
I'm on a budget, but I'm thinking that an underquilt would be a really nice step up. My ideal would be to have both the underquilt and some snakeskins that would fit over the whole rig to make my setup/teardown easier. I can sew well enough to make something serviceable (if not ultra-pretty).
One option that looked interesting would be to add a second bottom to my HH and fill it with down (probably from Speer). The down isn't cheap, but it's light and compact, and the rest of the materials would be minimal. I'm thinking of something like JustJeff's downhammock (http://www.tothewoods.net/HomemadeGearDownHammock2.html) but done as an add-on. I have some questions about this.
Will sewing to the Hennessey fabric weaken it (I'm only about 160lbs, so not pushing the limits there)?
Could I deal with entry/exit by basically adding a two-layer baffle with each piece of fabric sewn to an edge of the HH slit? (And some people thought it was like a "birth canal" before....)
How can I sew the outer cover (marking out darts?) to maintain a consistent loft distance from the hammock?
Is it possible to sew this on a standard sewing machine without ripping the bug netting off the hammock? It seems like by carefully rolling/folding with the slit pulled over the sewing machine arm I could make my way around the perimeter. Anybody tried anything like that?
Do I need baffles? How many? I would assume they should go lengthwise.
Is this a reasonable thing to do? If not, why?
Would I be better off just making a separate quilt? Which pattern have people liked? The reason I'm not starting with this is that a separate quilt seems like it would be heavier, possibly would sag away from the hammock bottom, and would be more fiddly to setup. More flexible, but I haven't had a night yet warm enough to sleep without a pad/underquilt.
I think that covers my questions. Please feel free to point out other problems or make other suggestions. I also saw the PreachersWife underquilt and they seem to be a great value, but the added bulk/weight of the synthetic insulation is sub-optimal because I'm trying to do the bicycle equivalent of ultra-light backpacking (small panniers, move fast).
Jeff and Slowhike started thread on down hammocks they made. I think both of them commented on the seam weakening the hammock. I think Slowhike's dumped him.
I prefer a second piece of insulation to a down hammock. If you get an unusally warm night it is harder to vent a down hammock. Weight wise you are only saving the weight of 1 layer of nylon. Probibly around 5 or 6 oz. With the quilt being seperate you also get a more versitle piece of gear that you can use seperate your hammock or wear it if needed.
There is a lot of talk of half length UQ. I have not used one yet, but they look promising. You would then use the pad under your feet.
Making an UQ yourself is not hard at all. Especially if you have sewing experience.
Check out www.featherind.com for down. I think mine came out to around $5 an oz with a 2 lbs min order. The site looks iffy, but they came through great for me.
I wouldn't permanently attach insulation to your hammock if you use it in the summer. Above 70 the cooling effect of the bottom goes from a problem to an advantage IMO. If you want a super cheap underquilt you can make one for about 10 bucks using $1 bin 1.1 nylon and quilt batting. Mine keeps me warm enough to the low forties. The drawback is weight, it weighs about twice as much as my climashield combat version (38oz vs. 18oz). Even if so I felt it was good practice before working with more expensive materials.