variable girth baffles

Hmm. Seems like my long-winded question didn't get any traction. How about this:

My 30* TNF beeline is much too warm for summer nights, and I'd like to make a cheap quilt. What summer-weight down sleeping bags/quilts are people using for warm weather and how are they constructed? What works and what doesn't?

Oh, and is there anything wrong with using breathable ripstop as baffles?

not going silent on you, just busy summertime.

i LOVE your budget bag idea. it's great, and you're recycling, which is near & dear to my heart. my neighbors who recently moved tossed a whole down comforter into the dumpster; i was going to fish it out in the morning to salvage the down, but the trash truck beat me to it! (lesson: dumpster dive immediately when the opportunity is presented)

i have never used ripstop to make baffles, but i can't see why it wouldn't work decently well. if you taper, i'd suggest keeping the center of the baffles at full height for a greater portion of the length. for example, if you have a baffle that is 40" long, have at least 20" of that baffle at full height (although a 3" high baffle will result in a pretty warm quilt!).

sew-through is much easier than using baffles, but of course you know that will result in a much less warm quilt. even adding a 1" baffle will make the quilt much warmer. i sleep cold cold cold, so for me even a summer quilt still needs to be baffled about 2".

I might make the baffles shorter, maybe 1" at their tallest. I will definitely make the baffles in the way you suggested, Seems like that will work well.

When I made the down comforter, I made 4" baffles, and it took LOADS of down to fill it. I used something like 8 jackets. The jackets were worn and weren't high quality, but inside the down was still beautiful. Despite the quantity of jackets it required, it was still a lot cheaper than buying one, and much much nicer. I don't think they even sell down comforters with baffle construction.

Does anyone else reuse down in this way?

My summer quilt velcros to a 'coffin-cut' ridge-rest pad. This gets the full length pad down to 11 ounces. It's more like a top bag when used this way. The shell has 42" of girth at the shoulders and tapers to something like 27" of girth at the foot. The foot end is a 7" radius semi-circle with one sewn thru line to make 2 channels. At the shoulders is a horse shoe collar to seal at the neck. It is over filled with 11 ounces of 550 down and the loft of each 5 inch sewn through tube is about 2.5 inches (very plump). I've used it down to 38 F with extra clothing (down vest) layed over the top of me. The total weight without stuff sack is 15.5 ounces using 1.1 ounce ripstop inside and out. Sewn through is easy (half the stitching for each line) but if I did it again I'd use 1 inch heigh nano-seeum netting baffles to let the down loft freer and eliminate cold stitch lines. To get the thickness of mine the actual fill power of the down was reduced quite a bit. Loose down in a baffled design works better than compressed down in a sewn through design. I'm 150 pounds, 5' 9" and my design is tight, but with velcro holding the quilt to the pad I can side sleep without drafts.

I've built baffled bags before. I never bothered to taper the baffle to the edge, I just gather up the material when I sew it shut. Netting is so light that the extra material weight is negligable and it assures there is plenty of material for everything to mate up and stitch closed. Making baffles an arc-like curve might help the bag conform to your body better. For a future bag I plan to curve the baffles in an arc and stitch them to the shells in a chevron pattern to keep down from settling to the sides. I find warmth is really improved by good collars at the neck/shoulder opening.

Netting doesn't unravel and is a better baffle material than ripstop which should be seared to prevent unraveling or loose thread clumping up the down. Thru-hiker.com has the lightest nano-seeum netting.

I hope this helps.

Thanks Neil. That helps a lot. I didn't think about the fraying of the nylon baffles trapping down.

A thought on weight savings; how will a sew through compare to a baffle design of similar loft? Initially, I thought sew through would be lighter, but I would probably need to use more weight in down since the stitching will compress a good portion of the down. Sounds like baffles are the way to go. I don't need the baffles to be puffy. If I make the tubes more narrow (using a greater number baffles), Will this reduce the amount of down required for each tube?

I really like your idea of the semi circle for the footbox.

How did you construct/attach the collar?

Another thing; I'm not a big fan velcro. Any idea for other methods of attaching the quilt to a pad. I know this probably depends on the pad. pad/attachment ensemble ideas would be appreciated. I'm thinking about purchasing one of the full-length insulating pad from gossamer gear.

A baffled design will have more constant loft; the baffled designs I made were also differential cut; the shell was 4" more in circumference than the liner at the shoulder, less so at the foot. For something with 1" baffles, a differential cut may not be worth doing.

With sewn thru or with overstuffed baffles the crowning of the fabric also eats up some of the length. I tend to oversize the cut fabric and it always turns out just right or a little small and so I've never really figured out exactly how much to add.

My sense is that once you get close to or above 2 inches of loft in a layer, the baffle is more efficient. It allows the down to loft more, reduces thin spots, and baffle weight is offset by more efficient lofting of down. Efficiently lofted down won't feel spongy the way an overstuffed tube will but will be fully filled none the less. Another benefit to this is a smaller stuffed item or one that isn't stuffed a stightly when you pack it away.

I like my baffle spacing to be about twice the design thickness of the bag, which means 5" to 6" spacing for the 3 season designs I've made.

Getting back to my sewn thru summer quilt, the collar was just attched at the edge, so the attachment is a thin spot. But for a baffled bag that is differential cut the collar would be sewn inside-collar-piece to the liner and outside-collar-piece to the shell. Then a blocking baffle can be be stitched-in to the internal seam allowances on the shell and liner. The collar is filled from the ends and is narrow enough that other baffles in the collar isn't needed. Or you can stitch both parts of the collar to the liner with whatever thickness spacing you want and let it hang from the liner.

If you don't like velcro I think your best option is a single layer bottom which turns the quilt into a top bag and at least a half zip is handy. But my summer quilt also has a collar slit halfway between shuolder and foot(velcro closing, I use the non-snag velcro) so it can be worn as a vest/serape. The velcro from the torso mates with the velcro from the foot since non-snag velcro is unisex (hooks and loops in the same piece). It looks dorky in use and always gets a laugh out of grumpy camp-mates before they make their coffee.

You might be able to sew #3 separating zippers to a foam pad and attach the quilt that way. It will weigh more than velcro but will be easier to use and adjust venting. The velcro isn't very convenient. I've thought of that method for self inflating pads as they ususally have a seam of heat sealed edge that could have a zipper sewn to, but I haven't tried it yet.

A light bivy sack also solves the pad/quilt attachment draft problem.

Many people use straps to batten a quilt down to a pad. Maybe even light bungee cord would work.

You can use rip stop nylon baffles. Holubar, once one of the best gearmakers in the business always used ripstop baffles. They are stronger. I would sew them in a chevron pattern to prevent down shift from side to side.