I'm thinking of using down from a down blanket I have (that I don't really use) to make an ultralight sleeping bag. All I would buy would be whatever material I'd use for the shell, etc., and save a little weight by making it only as big as I need it (I'm a small person).
If I stuff the compartments the right thickness right for the temperature rating, does the type of down matter? I think the down in the blanket is goose down- are there different types of goose down? If it does, and if it matters for temperature/weight, is there a way to know (by how it looks) what kind of down it is? From reading about fill power, it seems like the only way to know would be to weigh 1oz of down and then see how many cubic inches it would fill. This blanket was a friends (used for at least a couple years) and then they gave it to me about 5 years ago. I've washed it a couple times, which I realized afterwards is not the best thing for down. So I'm not sure what condition it's in, although the blanket is sooo warm and light, so it probably isn't that bad....
My goals are to save as much $ as possible and have something as lightweight and compressible as possible. My plan was to have more down on the top side of the bag, and maybe just a layer of shell on the bottom (basically like a quilt concept but a bag).
However, since I'm likely not going to use a sleeping pad since I'm leaning towards getting a hennessy hammock, I've been thinking about bottom insulation from the cold coming through the bottom of the hammock, and I was thinking of making the bottom of the sleeping bag lined with fleece or something, with the thought that compressed down doesn't really do much but fleece has air spaces in it even if you're laying on it...is that right?
As far as the temperatures/climate I'll be in- this is for a 2 month hike on the Appalachian Trail next May (starting late-May). Not sure of the exact starting point yet, but somewhere in the Northern half and hiking North, with the idea of getting to the end in Maine in 2 months with high mileage.
Based on those temperatures at that time of year, does anyone have any thoughts about this sleeping bag plan? Any thoughts about making more built-in insulation on the bottom so I don't have to use a sleeping pad inside a hammock? Is it likely to even be a big deal for late spring/early summer, if I'm wearing extra clothes, etc.? Also, any sleeping bag shell material recommendations? (So far 1.1 uncoated silnylon seems like the best option, just looking at fabrics that I can buy from quest outfitters, but are there better/lighter materials anyone knows about that I've missed?)