Hi everybody, I’m working on designing a sleeping bag and have some questions about the footbox. The bag is going to be similar to the FF Vireo UL where the top will be rated to 40* and the bottom rated to 20*. I’ll be using it primarily for alpine climbing, so often without a bivy or tent which means I don’t have additional protection from drafts or cold air.
From most of the tutorials I’ve read, they propose independently sewing shut the main bag body and footbox, then sewing together the two parts at a seam. However, this would create a sewn seam for air to leak, and at an especially crucial point. I wouldn’t be too worried if it was a 30* bag but if I’m planning to use this down to 20*, I definitely worry about cold feet. Have you guys found ways to forgo the sewn-through seam here? Or do you think it will be enough to just overfill with down and possibly enlarge the baffles around the foot?
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