I am getting addicted to these MYOG threads now-its so much more inspiring than looking at the manufactured gear and thinking; but I reckon they could have done this, or I want that on that...
I have 3 projects on the go at the moment; kinsman pullover, liberty ridge shell, and a spin tarp (making that up as I go- using 0.9oz thruhiker spin).
After hearing the response about the Whitney, I am thinking of giving that a go in a couple of months once I have finished these projects (I am pretty busy at the moment).
Is it true that it (whitney) has about 3.5 inches of loft in the torso? If so, would that be enough to get temp rating down to around 20F? I am thinking of also making a Nunatak AT like down quilt, that is about 50 inches long (I am 5'10") and using them in combination. I would need it to be good down to about 20F (-7C), or a few degrees more than that-I am a cold sleeper. I would need to make a down hood I think to add to the Jkt-probably a permanent attachment. Probably sewn-thru for the hood.
I am thinking of using 0.7oz spin fabric from thru-hiker (all the materials and down from there) for the lining of the quilt. The end and base of the foot would also be spin inside and out. The rest (outer) would be momentum90.
How would I go sewing the mesh baffles to the spin? Is it possible-has anyone tried, to either seem seal the spin with a tape or something, or to somehow weld/glue/tape the baffles to the spin and/or momentum without sewing? I hate the thought of using such great materials and then perforating them with leaky holes.
I figure that having spin on the inside wont be that much of a downside, with an open bottom from mid-calf to hip. This will be a superlight type set up for trips where Ill be pushing it and wont be sleeping that much-or in small batches of 3 hours or so-or at least wont be worried about a small amount of condensation. I thought I read that Aaron S has a similar thought with one of his quilts that he will use for his JMT attempt-god speed mate!
I have also thought of using spin all over and not worrying about seam sealing the top-it will need a bit of airflow to compress/loft. Then I wont have to worry about a Bivy. Ill use my small spin tarp. Ill have a WPB jacket-I am thinkin of getting an Outdoor Research Zeolot (Gore Paclite), which I can use over the top of the lot. I might need to size that a whole size bigger for the down loft.
More points for your thoughts-South Australia is pretty dry, but in winter can have very dewey nights and the odd hairy storm. I will likely be wearing synthtic thermal bottoms and top (polypro or whatever) which will most likely be damp from sweat when I retire to sleep. I figure the spin on the inside will protect the down, as well as boosting bag temp like a vapour barrier by a few degrees. I will likely have either a fleece (200 weight seems to work for me down here) beanie or a lighter weight merino (Icebreaker) Balaklava. Which will also be slightly damp when I go to sleep. Ill probably change into dry (merino blend) socks.
Looking forward to the discussion,