DIY sleeping bag overfill

[khumbukat]

Got an as new REI Halo-40 for $40 at an REI attic sale. 3 oz of 750 fill down for $16. 2.5 hrs of time and the result is 27 oz bag with no flat spots. Bag has side block baffles, so only top channels were filled. Each channel got from 3 to 6 grams of down. Tedious but not a difficult job. 30% increase in down mass. Ciao.

[Rocketman]

I'm interested in your project. I've wanted to do something similar.

Your pictures show how you easily got access to the top layer down chambers, and show your bowl of down.


I don't understand the association with the pencil evidently twirling around some down is a small container. Is this how you moved the down from the measuring container to the chamber?

I would like to more easily be able to copy what you had done. Can you explain a little more?

[skinewmexico]

I did that on some Luxury-lite sleeping bags I bought. You're right about tedious, but it was worth it.

[khumbukat]

The pencil is stuffing raw down, through a funnel ,into the small opening in the bag. Perhaps there is an easier way. This is my example. Jah Love.

[STICK]

So did the bag just have some flat spots when you got it? If so, would you say adding these extra 3 oz made it more of a true 40* bag?

[khumbukat]

I use the term "flat spot" to refer to what I consider insufficient fill. To me the stock bag did not have enough loft. I have always ordered my sleeping bags with the overfill option, if available. This bag came as a deal, so I chose to do the work myself. Yes, the bag is now a true 40 degree, or better, bag. Perhaps the bag was a lemon and thus ended up in the sale bin. It was 24 oz when I got it, true to specifications.
My main bag is a Marmot Helium EQ. I called Marmot to see if they would overfill it for me, and they said they would not. I then asked to buy some down from them and was told the price was $90 per ounce. I said "Do you mean $9 per ounce?" and was told "No it is $90 per ounce." The REI bag was for practice as I plan to do the same job on the Helium.

[buz]

Rocketman,

I have a couple of nice down coats that bit the dust, and I recycled the down, sorted it, and added it to two sleeping bags and a new down coat. It is tedious, but the results are worth it.

My .02. If you are using down from recycling, use paper bags, down doesn't stick to them, or dump the down into a paper bag, bigger is better, easier to handle. Lunch bags are perfect for weighing down. I did weigh the down for one project, not for the other 2, just looked at the filling, after inserting some. I used a hollow tube, about 1/2" diameter, maybe 6" long. It is actually a plastic gutter nail spacer that goes in the gutter, the nail thru it. To fill it, I used needle nosed pliers, grab some down, jam into tube, repeat until stuffed, filling the tube IN the paper bag. Then take the tube, place in small slit cut into whatever object to be filled, and use appropriate sized rammer to push the down into the pocket. Scotch tape the hole, move down around, figure out if another "tube" of down was needed. Only made very small slits, easy to resew by hand. After sewn back together, I used seam grip on the repair, really made it bombproof.

[d40mFc]

I like the idea of seam grip for down proof repairs.

[erichkopp]

I've been thinking about doing this for a while now. I have a 35* Big Anges bag that I'd like to bring down to 20* or so. I sleep cold as it is, so the more the better. How would you figure out how "x" amount of down would equal an increase in "y" degrees?

[Rocketman]

I've been thinking about doing this for a while now. I have a 35* Big Anges bag that I'd like to bring down to 20* or so. I sleep cold as it is, so the more the better. How would you figure out how "x" amount of down would equal an increase in "y" degrees?

If you go here:

http://www.westernmountaineering.com/index.cfm?section=Products&page=Sleeping%20Bags&ContentId=27

you will get the specification page for Western Mountaineering sleeping bags. This page lists the temperature rating and the weight and loft of all of their bags. I believe all of their bags use 800 cu. in./oz. down.

You can use this as a conservative guide to how much loft to seek to attain a specific temperature rating.

There could well be some differences if you are not using the high loft down. However, good data is rather hard to come by on this point.

Gerry Cunningham (of Gerry Gear big in the 1970's) wrote a book "Lightweight Camping Gear and How to Make it" and published a table of then current thinking on single layer insulation thickness and comfort temperature in a table. He actually got this from an older text which he specifies.

Temp *F Single Layer Thickness
40...........1.5
20...........2.0
0.............2.5
-20.........3.0
-40.........3.5

If you want to use this table, double the numbers for approximate net loft of the sleeping bag - the top and bottom together.

You might make a table of the Western Mountaineering information and compare this old design thinking with more modern thinking.

Most people say that Western Mountaineering is very good about their bags being warmer than claimed.

[burntoutphilosopher]

i have a question:

clearly you can lock down your own new seams that you make, but are you at all concerned with the ends of the seam you openned? how did you seal it back up?

sewing over it alone wouldn't keep it from eventually fraying back out ... perhaps a tight zig zag stitch over about an inch of the seam on both sides ??

[JAK]

Way cool. Nice work.