Im making a 48(head)x38(foot)x74 winter quilt(finished measurements). It is to have 3" of loft.


calculations for review:
(48 + 38)/2 = 42 average width

[42*74*3(loft)/850(Fillpower)]=11oz

11oz + 15%(cold sleeper) = 12.65oz.

Questions:

My question is, how spaced apart should i make my baffle lines?

How do i know how long or high to make the nanoseeum baffles?

Assuming the baffles were 6": Would it be a 9" wide piece of nanoseeum for each 6" baffle space to allow for 3" of loft?

Edited by isaac.mouser on 11/09/2010 17:48:18 MST.

I like to space the baffles a little tighter, about 5" between them. 6" would probably be fine.

If you're shooting for 3" of loft, then you probably want to cut a 3" strip of netting for each baffle. When sewn in that'll be closer to 2.5" or so, which should help maximize density/minimize cold spots while allowing great loft. Cut the 3" strip for the overall width of your fabric at that point... so for your topmost baffle, cut it at 48" long.

"Sewn thru baffles tend to create cold spots because the loft is restricted at the seam lines. With offset baffles the loft can remain constant across the quilt.

Don't overstuff them too much or you will defeat your purposes. If you overstuff them too severely you self compress the insulation. I dont believe you can realistically reach 30° with a sewn 'thru baffle.
It would be pointless, it seems, to have anything more than a 1.5" loft if you have shells sewn together. That will give a fair rating of 40° alone."

That has me retreating to a rectangular quilt instead of tapered, should i be worried?

Ike
Have you read "Make Your Own Gear - Down Quilt or Sleeping Bag"? It has lots of good info and drawings.

Try this Google search: "baffle spacing site:backpackinglight.com" Lots of hits there. Here's an example: Baffle thread.

My personal experience with approximately 2-1/2" high baffles is that 6" spacing is too big. The down shifts from on top of you to your sides. My experience with 5" baffles is better, however I think 4" would be better yet.

-Lance

Edited by Lancem on 11/10/2010 00:12:06 MST.

sewn through means shell sewn right to liner, no mesh baffle in the middle.

a tapered quilt with 2.5-2.75" baffles is about right. cut 3" stripes of mesh and sew with <1/4" seam. space them about 6" apart for best down control. I do 5" for 2" loft and 5.5 for 2,5"

hope that helps

-Tim

Ike,

Don't worry too much about overstuffing. Assuming you are not forcefully packing extra down in you should be ok.

Down actually increases it's insulation value the denser it is packed, it just doesn't increase as much as the weight increases (ie it's less warm/weight but more warm/inch...as lightweight backpackers we care more about weight).

A little overstuffing does have other benefits though, it keeps the down from shifting as much which provides a more uniform warmth and less cold spots..

Thanks guys! Back to work.

One thing to consider: can you get your hand into the down tubes? It's really hard to stuff a fist full of down into a tight tube.

Edited by vickrhines on 11/11/2010 17:42:36 MST.