[pct-l] new down in sleeping bag

[MAXINE WEYANT]

Hi Shon,  
I added down to a bag about 2 years ago, essentially converting a 30 deg bag to around 20 deg.  Here's why and how I did it, plus some details about down that you probably already know but newbies might not. Apologies to all for the lengthy post.
In 2007, I bought one of the first stretchy bags made by Montbell, before they came up with the current spiral version.  My other bag was a 650-700 fill mummy bag, and was too heavy and way too cold. I wanted the new stretchy bag because my knees and hips don't like to be confined in a parallel position all night long. The Montbell had 800 fill down, was much warmer, it weighed only 1lb 7.8 oz, and compressed into a very tiny stuffsack.  Unfortunately, it was way too long and too big for me but I bought it anyway b/c I was leaving on a section hike in 2 days and desperately wanted to shave some base weight.  I'm a small person and the dead airspace around me made me too cold.  Also, for some reason the baffles seemed too big for the amount of down in them, like there were gaps in the insulation. This was partly because it was a very compressible bag but also because the baffles in the stretchy bags elongate but the down doesn't always follow suit.  Presumably with the later version, the Spiral Hugger, Montbell managed to reduce the down gaps that occur when a horizontal stretch is applied (like when you bend your knee and let your leg fall out to the side, which you can't do in a traditional mummy bag.)   
I later learned that you really need to fluff up the more compressible down bags (800-900 grade down,) not just shake out the bag but grab each baffle from the inside and out and pull apart the mashed-up down to spread it throughout the baffle. It's really the air trapped in the down that traps your body heat. So, if you haven't been doing that, you might consider trying it before adding down to your bag.  It takes at least 3-5 minutes to get the down fully dispersed in all the baffles.  I suspect very few folks actually do that or even know about it, but it makes a huge difference, especially if you sleep cold like me. I roll around a lot, so having the down only on the top of the bag doesn't work for me.  
It helped, but I still wanted a warmer bag.  So I decided to make my bag smaller and add some down.  I quickly realized that most of the shortening had to happen at the foot and hood ends, or else the the zipper would curl, and I wasn't about to try to change out the zipper or shorten it.   I shortened one baffle at a time at the foot end by pinching and rolling about 1-2 inches of fabric circumferentially around the bag, then stitching it using a thin needle and polyester thread. By doing that, the shortened baffles were now "fuller" but the down wasn't compressed enough to lose it's effectiveness. I only shortened the fabric on the outside of the baffles, so now those baffles protruded more into the interior of the bag, which happened to take up a lot of the dead space around my lower legs and feet so I didn't have to add much down to that part.    
I bought some 900 fill down online from a company called Speer Hammocks.  A 3 oz bag, was about the size of a long watermelon and cost $30./bag.  After some trial and error, sneezing and flurries, I worked out the following method.  I transferred some of the down from the big bag into a large ziplock to minimize mess and flurries.  I then made a cone-shaped funnel out of paper, with the bottom of the cone tapered to a hole about 1/2" across. I cut a small hole (about 3/4" or less) in a baffle "segment" and inserted the cone.  The vertical stitching in this bag made the baffles non-continuous, so I had to add down to each segment within a baffle.   I then grabbed a small fistful of down from the ziplock, compressed it with my hand as much as possible, then shoved it part way down the cone. It was too big to shove through the hole but once it was already in the cone I used the pointy end of a chopstick to tease it apart and shove it down into the bag.  I then pinched the edges of the fabric together, stitched across it, then rolled it over and stitched it again.  Because I had to close each hole before going on to the next, I was a little concerned that I'd run out of down before I was done--especially since the remaining down in the plastic bag uncompressed, so it was hard to tell when it was halfway gone.  I had bought a second bag of down just in case, and ended up using about 1.5 bags.  
All the holes and stitching are on the outside of my bag.  Looks ugly, but who cares, plus it's probably more comfortable than if the stitching was on the inside.  I do have to be careful washing it because pulling too hard on the fabric, especially when wet, can cause the stitching to rip a little.  The fabric on these bags is very delicate anyway, so you can't machine wash.  I do have to use a larger stuffsack with this "new" bag, but it still weighs less than 2 lbs! (1 lb 13.9 oz.)  If I have room in my pack, I use an even bigger sack so I don't have to spend much time fluffing the down before bed.   Hope that helps, Dys-feng shui-nal