Adding down fill to existing sleeping bag – How?

[Monte Masterson]

You can send your WM bags off to San Jose to get overfill added and it’s been driving me crazy trying to figure out how they do it. I have some non-WM bags I’d like to beef up. Do they rip a seam and then resew? Any insight would be appreciated. Thanks.

[Jerry Adams]

since no knowledgeable person has responded : )

that would be best, to rip a seam and resew.  Some fabric is so lightweight it’s difficult to rip a seam without ripping the fabric.

after you ripped a seam, or even if you cut a slit in the fabric, after putting more down in you could pinch it closed a little further and sew that.  Maybe fold it over twice to hide the raw edge.

it would look a bit ugly and deform the shape, but if it was at the edge of the sleeping bag it wouldn’t matter

you could fold a strip of fabric or webbing or ribbon over the raw edge and sew through it.  That would consume less fabric to hide the raw edge.

[Alan W]

Optioally to working at seams, for my well used EE quilt, I selected an out of the way and low stress (flat, NON-seam) location on inside of quilt, shifted existing down away, carefully slit the thin fabric about 4″, added 2 oz of down, aligned slit edges, covered slit with super sticky EE repair fabric tape (had on hand for a Torrid jacket repair), and hand stitched an insurance ring around fabric tape perimeter.  To add the down, pack the down densely into a paper towel tube while working inside a clear plastic bag, place 1 end of packed tube through the fabric slit, and ram the down in with something like a wooden spoon handle. (I lost only 12-15 down plumes working in our small bathroom with door closed.) Finally, I spent another half hour on den floor with quilt laid flat to massage the new down where I wanted it. NOTE: my quilt has all baffles interconnected via a few small “orifices”.  Some bags/quilts have fully isolated baffle sections, and so multiple addition points might be needed. Be sure you understand your bag.  Skilled DIY folk & Factory addition might well rip and then repair seams, but that was more trouble/skill/equipment than I wanted to expend for a cosmetic effect, and 2 g of fabric tape was negligible weight.

[Monte Masterson]

Thanks for the replies.

I want to add down to an older Marmot bag with about a dozen separate horizontal baffles top and bottom, but I might only fortify the top. I found a YouTube video where a lady adds down to a quilt that over time has suffered from down loss and degradation. She cuts small slits into the shell and then pushes little pinches of down into the hole with a pencil eraser. After that she covers the holes with Gear Aid Tenacious Tape.

I also read an article online where a guy says he cuts small slits with a hot knife that’s been held over a flame and then adds down. Next he sews each slit together by hand. And lastly he goes over the slit with Seam Grip. https://www.wildsnow.com/818/sleeping-bag-modification/

[Jerry Adams]

I weigh the down in a plastic container.  Then, squish the down into a ball or bunch with my palm, grab the down between my fingers and stuff into the hole.

No sneezing.  No fans.  Move very slowly…

A little bit of down gets away, but very little.  When I’m all done I’ll vacuum any stragglers.

It’s a bit tedious.  If I did this for a living I’d have a tube and a pump to blow the down in.  I assume professionals don’t weigh the down for each tube – too time consuming.

[Jerry Adams]

before you add the down do you really need to?

maybe wash it

maybe just fluff it up as much as possible, fluff the down so it fills the baffles completely.

[Monte Masterson]

Oh yea Jerry I wash everything with Nikwax Down Wash Direct in a small commercial front loader (laundromat) and then I tumble dry bag/quilt on low for 1 to 2 hours, depending on how much down and shell weight. The last bag I just washed I threw in 3 tennis balls while drying to bust up the clumps and I think it helps some. But after washing I definitely inspect everything by holding bag/quilt up to a big window on a bright day (like lady in YT video) and seeing what needs to be moved around. I also massage the baffles to get as much loft as possible.

I’m convinced many commercial grade down fills degrade over time and simply don’t loft as much as when they’re newer, no matter if they’re properly washed and dried or not. I also agree with the guy in the article I linked when he says that most bag manufacturers leave at least a little unused space in each baffle.

So I see 2 reasons for adding down fill to an already finished bag 1) to simply improve a bag/quilt that is already lofting well because you just want that added performance and optimum warmth to weight ratio, such as the overfilled WM bags from Hermit’s Hut for example. I mean why not have full baffles, at least as long as it’s not overdone? 2) Second reason is to shore up an older well used down bag that won’t loft adequately anymore and it shows a lot of empty cold spots when help up to bright light.

3 down choices, each coming in 3 oz bags. 1) 800 Duck Down $23 or 2) 850 Goose Down $35 (both from Dutchware) or 900 Goose Down $50 from Thruhiker.

[Jerry Adams]

Same here.  Last step is to hold to window and beat the down to fill the baffles as evenly as possible.

Yeah, that makes sense about down degrading and manufacturer not putting enough down in.  I had an old down sleeping bag that got so clumped that I got rid of it and wrote off down.  Until I changed my mind back : )

I always weigh the down for each baffle and put in 30% more than needed.  Next time I’ll probably do 50%.  If you put in overfill, it still adds more warmth, but the warmth per weight suffers a little.  But it minimizes the problem of shifting down in a baffle.

I’ve used 900 from thru-hiker, 850 treated goose down from RSBTR, and 850 untreated goose down from that vendor that’s no longer in business and I can’t really tell much difference.  I would be interested in hearing your experience.

[Sam Farrington]

There has to be a seam.  Otherwise, how would they get the original down in there in the first place.   Once you find the seam where they must have inserted the down, you can delicately open the seam at the points where you wish to add down.  I say delicately, because even though the tool is called a seam “ripper,” nothing should be ripped.  Rather, the connecting threads should be located, and severed to open the seam once you find it.

Once the down is added, you may have to do some top stitching to close the seam.  But am wondering why you would add to a lot of down that is basically worn out.  Perhaps it would be better to replace all the down if you can find some good stuff like they use at WM.  But maybe that is a job better done by Rainy Pass or the like.  Come to think, maybe WM would refresh the down as needed.

 

[baja bob]

Rainy Pass is so expensive that it would be more cost effective to buy a new bag at that point. I have a very old WM bag that I contacted WM about to get the down refreshed and maybe update the zipper as I read about someone else having it done. This particular bag is so old that it has a full wrap around metal zipper. Their response was not super clear nor helpful and I have not followed up.

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