Insulation Queston

Your UQ idea should work – but I wouldn't use the outer IX layer. Putting it outside of the down could cause it to hold some moisture and make it slow to air out/dry.

Otherwise, give it a go and show us pics!

I am not too sure if the underquilt is such a good idea. One of the problems I have with all hammocks is the extreme amount of underlayers needed. Coupled with body compression laying on top, and they often start bottoming out at around 20F-30F, regarding weight/per insulation. Often a more rigid foam type insulation is wanted, like a closed cell foam (CCF) pad…often a couple or three layers. It is hard to find a better insulator than snow, though, it is only good to about 28F-30F, then it starts getting wet with compression. Generally, thick pads are used as much to keep the melt managable, and away from the bag, than to supply real warmth. Though it works both ways…

Anyway, 550 fill is likely a good choice for stuffing between two layers of synthetic fill. It will resist compression some, but also trap small pockets of air in it, leading to some insulating effect, even laying on it. Good high lofting down will likely perform no better, because of the compression. The downside? Well, it will likely perform no better than an equivalent weight of the synthetic fills…it will just last longer if properly laundered. Without some thurough analysis, it is hard to say. So, take this as a best guess by a semi-literate.
Fact: 550FP is about equivalent to many synthetics in insulating effects when new.
Query?: 550FP will compress a little more, but might be damaged more do to the preponderance of stemmed breast feathers with down-like barbules, instead of down plumes (known, but hard to tell how it will compare to synthetics.)

Todd- Maybe use two inner layers of IX instead of an outer? I'd like to get down into some cold weather with it.

James- Maybe I'm not understanding exactly what you're saying. The underquilt shouldn't experience any compression problems during use. It is on the outside of the hammock and attached to my suspension with shockcord, so there will be minimal compression.

The down will be able to fully loft, I'll dart the baffles so that the down isn't "sandwiched" between the layers of IX, but rather the IX are big roomy baffles into which the down will be sewn. It's exactly like a normal UQ, just some extra synthetic insulation to add to the down's properties. Is that what you were warning against? If so did I do a better job explaining myself?

I'll get a rough sketch done and post it here soon

I am not sure what James is trying to say any better than you but I can tell you that the difference between 55 fill and something like 850 fill is the quality of the down. There is absolutely nothing wrong with 550, you just need more of it to get the same insulating properties as the 850 fill, which is why most UL people try to stay away from it. Personally, for what you paid I think you'd do just fine with the project with the two inner layers of IX, it might be heavier than other more expensive options but it still should keep you warm!

The second paragraph of what James said is more or less accurate based on my understanding of down fill, but the first is easily debunked by Shug's Intro to Hammock Videos. The 0 degree UQ I have on my wish list is the Warbonnet Winter Yeti UQ, just like Shug's, and from his videos it looks to packs down to about the same size as a Neo Air All Season Mat and it is the same weight and is more packable than a Ridgerest.

Insultex is interesting stuff but it isn't magic. I think it is fine to give wind protection and it has some reflection qualities, but it won't equal a good thick layer of fluffy fill.

I would put one layer of IX on the hammock side and definitely not on both. As others said, it won't allow the down to dry. An all-down UQ will pack smaller too.

My hunch is that adding an equivalent weight of down would be warmer than the IX layer. A space blanket could be added any time you want the vapor barrier and added reflection warmth for less weight, cost and complexity.

High end down pillows can be a good source of less expensive down fill (note I didn't say "cheap"). Bloomingdale's "My Luxe" pillows have 800 down fill. Their "Flair" pillows are 600 fill. You can get them on eBay now and then. A big pillow can have a LOT of fill– they are stuffed for firmness.

My most recent research says that IX isn't exactly packable, meaning to store it I'd have to fold it over a couple times and roll it up. I was looking forward to this but now I don't know if it's such a good idea as making a purely down UQ. The space blanket is a good idea. Better to know now than later I suppose.

Odd question… I know that fill power has to do with how much space the down takes up (1ounce=1liter for 900fp or something like that, I honestly don't know)
But what makes down take up more versus less space?
Is there anything (even obnoxious time consuming things) that I could do to 550 fp down to give it a better fill power? Even if I end up with a (slighty) lower quantity of it (I have 54 ounces to use)

the 900 means that 1oz of down occupies 900 cubic inches of volume when uncompressed. what affects fill power is the ratio of feathers to down. Down is very fluffy, so fills up a lot of space. Feathers, less so. I don't think there is any practical way to sort the down from the feathers, so i don't think there is anything you can do to improve the fill power. I read that you were thinking of using m50. Don't. Your money would be much better spent on higher quality down.

Is the packability issues with IX really a huge problem?

Would Climashield be better than IX to use in this, or would throwing this all out the window and only use down still offer the best warmth to weight ratio?

I've seen 900fp pieces of clothing with 95/5 ratio of down to feathers, the same ratio as this 550fp, so maybe I'm just not grasping how all this works.

I've been doing a lot of research today, and asking a lot of questions, so maybe my head is just too full of stuff.

EDIT: And if I do buy higher quality down, what should I do/make with the stuff I have?

"Maybe use two inner layers of IX instead of an outer? I'd like to get down into some cold weather with it."

Yeah, no outer will save weight. Just not sure if the IX will be "downproof" or "down resistant". As for pleats/baffles in IX:

http://www.hammockforums.net/forum/showthread.php?t=38256

http://www.hammockforums.net/forum/showthread.php?t=29606&page=2

I would go all IX, or IX w/ Climashield, or all down, or down w/ Climashield outside that. That is, all of these options I would prefer to down w/ IX.

When using IX, I definitely wouldn't use an inner fabric liner since it will be next to the hammock.

I experimented with IX and it is okay for summer use, but I would use an under cover with a simple IX underquilt, which adds weight, expense and construction time. IX is touted as magic, but it is just some polyethylene foam with a reflective layer and some micro perforations in an attempt to make it breathable (it really isn't). I think two layers of loose space blanket will deliver about the same performance if used with an undercover.

2QZQ sells under covers for $35 in ripstop or silnylon, which I think is a bargain. An undercover can be used with Garlington Insulators, which are the quick and dirty bottom insulation solution for hammocks— for summer stuff, IMHO. See http://www.garlington.biz/Ray/HammockInsulator/Insulator.htm . If you like the under cover idea and use a poncho, it is simple to make a combination poncho/under cover and get the multiple use weight advantage.

IMHO, once you get much below 50F you need some real insulation. IX blocks wind and convection, but it is nowhere near what a thick layer of insulation like a lofty down, Climashield or Primaloft UQ will provide. Of course the down/synthetic debate on an underquilt is identical to their use in clothing or a top quilt: wet performance, durability, cost, loft/weight, etc. For MYOG, using synthetic batts does allow simple construction and sewing techniques. One thing that helps with underquilts is using a design with a differential cut– tight to the bottom of your hammock and loose on the outer cover to allow maximum loft. You want to eliminate any gaps at ends and sides, and a differential cut helps. Simple flat synthetic underquilts need some care for pleating and shock cords to snug them up on the ends and prevent gaps. Making a full length UQ gets around that problem, but then you have the extra bulk and weight. I've thought about a UQ with plain ripstop ends to help avoid gaps and simplify suspension while avoiding the bulk of running the insulation all the way out to the ends. It's all compromise, like any gear design.

In very cold weather, I think a full length UQ is worth it. Shug has a video on hammock camping at -26F! http://www.youtube.com/watch?v=Jnoo4BPe2eo&feature=relmfu