I know it's been done before. I've read a couple of threads on this site, but I wanted get some feedback regarding the insulation factor. I'm thinking of taking two 40 deg sleeping bags, lay about one to two inches of polyfill between them and stitching them together. I'm hoping to drop the rating to maybe 30 deg or better. The sleeping bags are $10 each at Wally World and the pollyfill probably another $15 to $20. I have some Parachord that I can stitch in or maybe I'll invest in some shock cord for attaching it to my hammock.
This is would be a temporary solution until I can invest in a real underquilt. I'm hoping to test this on a Scout Outing in March.