Sleeping Bag Mods — Adding More Down Fill

Post by blogger | August 10, 2005      

Preparations continue here for our Wyoming wilderness adventure. Much of the gear we’re using translates to backcountry skiing, especially our sleeping bags. I just got another Marmot Fusion sleeping bag. As no gear in the Dawson household shall remain unmodified, I opted for the 30 degree rated Fusion, then added 12 ounces of extra goose down to the upper tubes in my torso area, for a total weight of 3 pounds. This should result in a bag that can be used upside down during warm nights, but used in normal position with the stuffed tubes on top, should easily keep me warm down to 15 degrees or so.

All this with the Fusion construction, which places fiberfill on the outside of the bag to protect the down from moisture.

Marmot also makes a 15 degree rated Fusion “15” that weighs just over 3 lbs. After my son has tested the 15 all summer, we figured the 15 is really only good to perhaps 20 degrees, so my modified Fusion 30 bag is warmer and weighs less — that’s the theory anyway! Mods aside, both of the Marmot Fusion sleeping bag models easily offer the best combo of weight, reliability and warmth on the market today.

Tech details: For years I’ve “overstuffed” down filled clothing and sleeping bags. It seems like almost all down filled items are made with enough volume for more fill. I’ve been told this is intentional, as it allows the down to achieve maximum loft and thus you get the most insulation for your money (and for the weight of the down). In theory. In reality, I’ve never found any dow- filled equipment that didn’t benefit from a bit of extra packing. The trick is to figure out where to slit the fabric, and how to sew it back up. Simplest method is to just work from the inside where appearance isn’t an issue (a must with Fusion products, since the outside insulation layer is Primaloft).

Heat a thin knife and use is to hot-cut slits that’ll just fit your hand. On a sleeping bag, make your slits at the end of the down tubes, near the seam that defines the side of the bag (between top and bottom). Stuff down by hand through the slit, measuring by handfuls. Don’t over-fill. You just want enough down added to plump out that tubes. Close the slits by hand stitching, then seal with urethane seam sealer so down doesn’t leak from your stitches. Hand filling with down makes a big mess. Make a temporary “down room” in your house by using a draft free smaller room such as a larger bathroom or small bedroom, or set up a dome tent inside your house. Go in your down room with all your tools, including dust mask and vacuum cleaner. Lock the door behind you, do the deed, then vacuum the evidence.

Older sleeping bags that haven’t been too abused can work well as down donors. Good quality down (few larger feathers) lasts well unless it’s been washed many times or contaminated with who knows what. You can tell if the down is bad by examining a sample; look for matting and clotting of the feathers. If in doubt, buy new down from any of the do-it-yourself outfits. If you buy new down, get the good stuff, at least 700 fill. Don’t use down from pillows, quilts or cheapo sleeping bags — it’s low quality stuff that’s not worth the effort.



  Your Comments

  Recent Posts

Facebook Twitter Email Instagram Youtube


  • Blogroll & Links

  • Welcome to Louis (Lou) Dawson's backcountry skiing information & opinion website. Lou's passion for the past 50 years has been alpinism, climbing, mountaineering and skiing -- along with all manner of outdoor recreation. He has authored numerous books and articles about ski touring and is well known as the first person to ski down all 54 of Colorado's 14,000-foot peaks, otherwise known as the Fourteeners! Books and free ski touring news and information here.

    All material on this website is copyrighted, the name WildSnow is trademarked, permission required for reproduction (electronic or otherwise) and display on other websites. PLEASE SEE OUR COPYRIGHT and TRADEMARK INFORMATION.

    We include "affiliate sales" links with most of our blog posts. This means we receive a percentage of a sale if you click over from our site (at no cost to you). None of our affiliate commission links are direct relationships with specific gear companies or shopping carts, instead we remain removed by using a third party who manages all our affiliate sales and relationships. We also sell display "banner" advertising, in this case our relationships are closer to the companies who advertise, but our display advertising income is carefully separated financially and editorially from our blog content, over which we always maintain 100% editorial control -- we make this clear during every advertising deal we work out. Please also notice we do the occasional "sponsored" post, these are under similar financial arrangements as our banner advertising, only the banner or other type of reference to a company are included in the blog post, simply to show they provided financial support to and provide them with advertising in return. Unlike most other "sponsored content" you find on the internet, our sponsored posts are entirely under our editorial control and created by WildSnow specific writers.See our full disclosures here.

    Backcountry skiing is dangerous. You may be killed or severely injured if you do any form of ski mountaineering, skimo randonnee and randonnée skiing. The information and news on this website is intended only as general information. Due to human error and passing time, the information, text and images contained within this website may be inaccurate, false, or out-of-date. By using, reading or viewing the information provided on this website, you agree to absolve the owners of Wild Snow as well as content contributors of any liability for injuries or losses incurred while using such information. Furthermore, you agree to use any of this website's information, maps, photos, or binding mounting instructions templates at your own risk, and waive Wild Snow owners and contributors of liability for use of said items for ski touring or any other use.

    Switch To Mobile Version