Summer Quilt/Overbag
Another weight saving project - a down summer quilt, which when used as an overbag for our 30F sleeping bags should allow us to sleep comfortably to ~15F. It's basically a down blanket with draft flaps. Velcro on the flaps allow it to be closed up to make it more like a hoodless sleeping bag, and the open foot area can be cinched shut with drawcord. It also has extended straps at the hips and foot-end that will wrap under a sleeping pad to hold it in place when used as an overbag. edit: This quilt is very similar to the Nunatuk Backcountry Blanket (great minds must think alike).
I made NeatoWoman's quilt first. The down surprisingly was a lot easier to work with than I had imagined. The quilt is 5'9" long, 50" wide at the top and hips (+ 10" of flap), and tapers to 36" at the foot (+6" of flap). The two pairs of straps on the quilt hold the flaps in place under a sleeping pad when used as an overbag. The baffles are 1" high, and 7" apart (I'd probably make it 5" or 6" if I could do it over). I added some extra down so it lofts to ~1.3". It weighs only 14oz (5.5oz fill), and is probably good to ~50F, perfect for our summer hikes.
Materials cost about $80, most of it being the down. It's made of 1.1oz nylon ripstop, no-see-um netting for the baffles, and 800fill-power down. I got all the materials from Thru-Hiker.com. It took about 20hrs spread over three days to finish it.
Update 12-02-05
My quilt is now done. It took me about 15hrs this time. Total weight = 16oz, with 6oz of fill (1.5oz overfill). The baffles were 6" apart, which makes it loft more evenly with less shifting of the down. I also added 0.5oz of fill to NeatoWoman's quilt for a total of 6oz of fill (2oz overfill). That made her 7" baffle spacing fill out better. My quilt has ~1.3' loft and hers now has ~1.4" loft.
NeatoWoman's quilt in yellow/black, mine in gray/black.
Set up as an overbag. It has plenty of room to allow the sleeping bag to
turn.
Testing
I sleep warm, and typically try to wear minimal clothing to bed. I also have a hard time sleeping if my feet are too warm. I ran a some preliminary tests out on my deck. My sleeping pad is a full length ridge rest and my only luxury was a small pillow.
- Test#1: 43F, very slight wind, wearing my summer sleep gear (silk wt long underwear, and lightwt sock liners), 2.5hrs on my deck. I closed up my quilt and used a Montbell UL Thermawrap over my head. This is about as low as I would want to go with this setup. I felt OK, and though I could have survived a night at that temperature, I probably would have to add some clothes or break out the space blanket at some point.
- Test#2: 46F (inside tent), no wind, wearing silk wt long underwear. I closed up my quilt and used the thermawrap over my head. Started out warm (I was well fed before going to sleep). Sometime in the middle of the night I noticed a slight cold creeping thru the top of the quilt. It wasn't cold enough to keep me awake, but an extra base layer would have helped keep me warmer.
-Test#3: Overbag test - started at 28F, low 19F, calm skies, medium weight long johns, using a Feathered Friends Osprey 30F sleeping bag (it's more like 25F with upgrades and overfill). I started with my quilt set up as in the above picture, and was very, very warm. Woke up at 3am sweating (temp was 23*F). I opened up the bag to air out, closed up again, but left the hood uncinched partway. This really helped to keep me aired out, yet I remained very warm for the remainder of the night.
I would put the minimum comfortable temperature rating of my quilt at 50F. You could pass the night at 45F, but colder sleepers would definitely need to add some extra layers to bed. As an overbag it will easily add 10F - 15F of warmth.
Materials:
2.5 yds 1.1oz nylon ripstop with DWR (black)
2.5 yds 1.1oz nylon ripstop with DWR (light color)
1 yd no-see-um netting
10 ft 1/4" flat drawcord
4 mini cord-locks
8" velcro (3/4" wide)
6.0 oz 800 fill-power down.
100% polyester thread
Tools:
tape measure
straight edge/yardstick
hot knife & cutting board (or scissors will do)
scissors
sewing machine (with optional roller foot)
scale capable of measuring at least 0.1oz increments (1 gram increments is preferable).
tape
magic markers
patience
Design: I made the length of my quilt 6" longer than my height. The girth of 64/60/42 was determined by adding 4 inches to all the measurements from my regular sleeping bag, It is similar to most wide mummy bags. The insulation is 50" wide at the shoulders and hips, allowing it to wrap under me a little, while still leaving plenty of room to move around. I used 1" baffles, but with the overfill the loft is closer to 1.4". I allowed 2" for all seams, it's easier to work with. They can be trimmed later if you want narrower seams.
diagram for my 6'6" quilt with 6" baffle
spacing.
diagram for the 5'9" quilt with 6" baffle
spacing (7" for first baffle and
last two baffles).
diagrams for a 6'6" quilt that I never made. It has more insulation in the foot
area - better for colder weather.
The numbers shown in between the baffles are the fraction of the total fill that is stuffed into each chamber, i.e. 0.083 X 6 oz total fill = 0.5 oz down for the top chamber.
Approximate temperature vs loft ratings can be found in this article on the Thru-Hiker website.
down calculator: (area) x (inches of loft) / (fill power of down) = ounces of down needed
insulated area of the 6'6" quilt = 3536 in2. With 1" baffles it works out to 4.5oz of 800fill; I used 6oz.
insulated area of the 5'9" quilt = 3128 in2. With 1" baffles it works out to 4oz of 800fill; I used 6oz.
insulated area of the other 6'6" quilt = 3828 in2. With 1" baffles it works out to 4.8oz of 800fill
*You'll probably want to add at least 1 oz of extra down to better fill out the chambers. Use 2 oz extra overfill to really puff it up.*
Laying out the Pattern: Use a dark color for the bottom shell and a light color for the top shell. The ripstop comes in widths of 60-64". It is never cut straight, and the gridlines running across the width are never straight either. To get a good straight line with right angles to the edge of the fabric, fold the fabric width in half. Line up the two edges of the fabric along the entire length, and make a mark at the top on both edges.
edges lined up (bottom of picture), marks are bottom right
in red.
Unfold the fabric, line up a straight edge with the two marks and draw a line across the top of the fabric with a marker. You now have a line across the top of the fabric at right angles to the edges. Use this line to help lay out the pattern.
Start with the darker (bottom shell) fabric first. Tape the fabric to the floor and draw the pattern. Silver marker works best on dark fabrics. Lay the other fabric on top, line up the edge where the pattern begins and tape the fabric down. Trace the pattern onto the brighter (top shell) fabric. Leave the fabrics taped down and cut thru both fabrics with a hot knife. Put something solid underneath to keep from burning the floor (I used a 1/4" thick sheet of plastic as my cutting board), and use a metal yardstick to guide you. The fabrics will melt together, but can be pulled apart very easily. You've now got two perfectly matched patterns.
Measuring the pattern.
Baffles, the tedious part: I suggest 6" spacing between baffles. Add 1" to height of the baffles for seam allowance. A metal yardstick is ~2" wide, so it was the perfect guide for my 1" baffles (1"+1" seam allowance=2"). I just laid the yardstick on top of the mesh and cut with the hot knife, using the yardstick as the 2" guide. I could cut a series of baffles very quickly this way. Cut them at least 2" longer than needed. Line them up on the bottom shell pattern with ~1/2 inch overlapping the baffle marker lines and tape them down, leaving the marker lines visible (see 2nd pic below). Sew the baffles going ~1/4" - 1/2" past the edge seam line. After finishing the baffles on the bottom shell, remove the tape, place the top shell (brighter) fabric on top. Make sure the flaps are on opposite sides, and line up the patterns (you should be able to see the patterns though the fabric). Starting from the foot end, pin and stitch the foot together (leave the seam unfinished). Flip the quilt over so the top shell (brighter) fabric is underneath (see 3rd pic below). Working your way up, do one baffle at a time. Tape and sew the baffle to the top shell as before. Repeat this till you get to the top, removing the tape after each baffle is complete. Sew the top seam (leave it unfinished). Tip: I find I get less stretching of the baffle material when I use a roller foot on my sewing machine.
taping and sewing the baffles.
Side Seams: Line up the marker lines on both fabrics along one side of the chambers. Pin and sew along the marker line. Trim the excess baffles, and trim the seam allowance to ~1", fold it under and finish the side seam. It will be about a 3/4" seam (see pic below).
a finished side seam and baffle (note the stitch overlap
of the baffle).
Filling the Chambers: Place the bag of down on the scale and measure by subtraction. The down from thru-hiker is packed tight so you can just pinch off clumps of down and stuff it. Stuff the chambers one at a time from the open end and tape shut. Continue until all stuffed. Sew and finish the open end of the chambers the same as the other side seam.
Tips - Use a scale that can measure grams, it's more accurate and you won't end up with many unevenly stuffed chambers. Dust your hands with talc or chalk to keep the down from sticking to your fingers. If working with loose down, use a vacuum cleaner with a sock over the hose to collect clumps of down. Suck up a bunch of down, it'll collect in the sock (be sure to hold the sock so it doesn't get completely sucked into the hose), turn off suction and transfer wherever you want. Make sure to point the exhaust AWAY from where you're working. You can use this trick to retrieve loose feathers off the floor.
Finishing the Flaps: The hem on the flaps is going to be 1" (or smaller if you like) and it really doesn't matter which way they go. Fold them over once so the fabric edge lines up with the marker line. Fold it over again and stitch (the marker line should now be on the edge, and you'll have a 1" hem).
Make the straps 1.5" wide from leftover material. I put one at the hips and another at the second baffle line from the foot. To make the straps fold a 4-5" wide X ~22" long piece of fabric in half down the length of the fabric, and sew a line 1.5" from the fold. Trim the excess to ~1/4", and turn it inside out. Add a second line of stitching along the seam edge. Cut it into 10" and 12" pieces. Put the longer piece at the second baffle line from the foot end, and the shorter piece at the hips. Tuck ~1/2" of the strap end under itself and sew to the flap hem. Leave the outer end of the straps unfinished for now. Repeat this process on the opposite side.
Cut 6 matching sets of velcro, 1.5" in length. Four sets of these will be on the flap hem along the edge of the quilt; one at the foot (above the drawcord sleeve), one on each strap, and one in between the two straps. The hook side of the velcro will face up on one side of the quilt and corresponding loop side of the velcro will face down on the opposite side of the quilt. To finish the straps, you will need to measure a distance equal to one half the width of your sleeping pad, from the side seam out toward the unfinished strap end, and mark it with a marker. Trim the strap to 2" past the mark. Fold the trimmed end of the strap to the mark and sew a piece of velcro over it. Be sure the velcro is on the same side as the piece of velcro at the hem, and use the hook or loop velcro that is opposite from the one at the flap hem; for instance, if you have the hook velcro on the strap at the flap hem, use the loop velcro on the end of the same strap.
Head/Foot Drawcord Sleeves: To finish the foot seam to make the drawcord sleeve, fold over the unfinished edge of both fabrics ~1/4" and stitch. Fold again so the 1/4" stitch lines up with the bottom of the last chamber and sew. Finish the head seam the same way.
Cut 70" and 48" pieces of drawcord for the head and foot drawcord sleeves (width of head plus 6", width of foot plus 6"). Singe the cut cord ends with a lighter. To help thread the cords thru the sleeves, hook a paperclip at one end of the cord (make sure the cord is hooked on the smaller end of the paper clip). Slide on mini cord-locks and tie small loops on the ends of the drawcords.
detail of the foot end showing the finished flap hem, drawcord seam, velcro and strap closures.
all done.
*update* Footbox: I made an insulated cover for the footbox. It covers the small hole that forms when cinching shut the foot box, much like a stuff sack cover. It's 6" long, the width tapers from 12" to 6" (see pic). I added 1" all around for the seams. Sew shut the three shorter sides, trim the allowance to ~1/2", and turn it inside out. Sew shut half of the 12" side. Stuff it with 0.05 to 0.1 oz of down. Sew shut the rest of the long side. Fold over the edge of the 12" seam 1/4" and stitch. Place the cover on the bottom shell in the middle of the last chamber, with the 12" side facing the bottom of the quilt, and the shorter, 6" side facing the top of the quilt. Fold the 12" seam in half again, line up the 12" stitch line with the stitch line that forms the drawcord sleeve and sew the pouch to the quilt (sewing directly over the stitch line).
footbox cover.
Links
Thru-Hiker.com - for supplies. A down quilt project is in the workshop section. Also, folks on the message board are very helpful.
The Lightweight Backpacker - make your own gear page. #1 and #4 under sleeping section.
TLB message board - more helpful people from the the lightweight backpacker site.