An idea for how to limit (if not entirely prevent) the cold-spot-on-top problem that Joe had, occurred to me after a little thought on the topic. My sewing experience is limited to an myog pack I made this summer, and I have never made a down quilt before – or a quilt of any sort – but I have been looking into it, and I think I have a decent grasp of the general methods. I am not sure whether this would work, but here is my idea.
If the problem is that down tends to shift to the sides of the quilt (which it does because of gravity, then to solve or at least alleviate this problem you need a force to counteract gravity. This idea is under the “better baffles” category. You could change the spacing of the baffles, to make them narrower. Another thing you could do is change the profile of the baffles. As far as I know, baffles are long rectangular strips sewn into the quilt. This means that the quilt is the same thickness its whole width. What if the baffles were contoured? What if they were strait on the bottom, but curved on the top, so that the middle of the quilt was thicker than the edges. If the final volume was the same in relation to the amount of down used, wouldn’t the relative thinness of the edges of the quilt, and the relative thickness of the middle of the quilt, naturally force more down into the middle of the bag, where it is most useful, and where it tends to want to leave? It might not actively force down from the edges, but a few good shakes before climbing in to get the down in the center of the bag, then the profile would reduce the tendency of the down to shift.
A normal baffle in a down bag, followed by a contoured baffle:
nevermind. i am having trouble uploading the ms paint diagram i drew. i think it may be because i am currently travelling in Syria, and there are restrictions on what you can do on the interntet. i cant upload pictures or files to gmail either. oh well. picture, then, the thength-wise profile of a load of bread. it has a flat bottom, and two square ends, however, the top of it rises in a gentle curve to the middle of the loaf, and then gently back down to the other side. now imagine this shape stretched to the width of the quilt. thats what i am imagining.
The curve on the baffle could be even more or less extreme for an greater or lesser effect. I don’t know if this has been done, or whether it would work, just and idea I thought I would share. One problem I could foresee is that the down could shift anyway, which would in effect be compressing the down further, making it less thermally efficient. Or it would cause the edges of the quilt to “pucker” as the down forced each baffle into more of a cylinder shape (greater volume for same surface area). What do you all think of this? Has it been done? Does it work/would it work? Am I crazy?
(I have been somewhat obsessed with these forums for about a year now, but I haven’t ever felt I had much to contribute, so don’t be too rough! Just kidding, be however you like, i have tough skin)