I made this sleeping bag to replace a heavier and cheap bag. It uses 5 oz/sq yd climashield apex synthetic insulation. Total weight is 3lb 4 oz including stuff sack and small pillow.
What I would do different: Use a lighter shell materiel, such as Membrane 10 Nylon at .66oz/sq yd. Use more insulation. This bag is only comfortable down to about 30-40F. I've been in it in the low 20s and even with everything I brought on, I was still too cold to sleep. Use lighter insulation. Down or Primaloft One would reduce the weight of the bag even further. Primaloft One is about 10% warmer for the weight than Climashield Apex. I used a layer of mylar spray glued onto the inner shell layer to experiment with radiant heat reflectors. It was hole punched for breath-ability. I'm not convinced the mylar made a big difference. The weight and cost of mylar + glue would have been better allocated to more insulation.
1: Lay out two pieces of lightweight shell materiel, one on top of the other. Each piece should be about 60"x80". I used 1.4 oz/sq yd ripstop nylon. 2: Sew around 3 of the sides, leaving the top open. Double or triple stitch for strength. 3: Flip inside out to hide seams. 4: Insert insulation, cut to the same size as the "pocket." 5: Once insulation is appropriately spread through the bag, apply a couple seams to fix the insulation in place. I did one long seam around the perimeter and 3 seams down the length. Leave the top open while you do this so you can re-position insulation if needed. 6: At the top of the bag, roll the hem inside. Sew to close the bag from the top. 7: Optional. Sew on zipper. I used a full zipper so the bag can open into a quilt. Half zippers save some weight. 8: Optional: make a stuff sack. 9: Optional: use extra insulation and shell materiel to make a lightweight pillow.
Required Materials:
2.25 Yd Climashield Apex 5 oz/sq yd About 5 yd of shell materiel About 9 ft zipper if using zipper
