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Down pants
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Casey Cardwell
(Niles) - MLife

Locale: On the Dirt in Oregon
Down pants on 01/09/2008 17:43:18 MST Print View

I tried searching for some info on this, but searching "down" doesn't come up with a very accurate list.

So, I'm looking for any help, or advice on making my own pair of insulating down pants, similar to Montbell's UL Down Inner Pants.

I was planning on using 1.1 uncoated downproof ripstop from Ed Speer's site, along with his 900 fill down.

Can I just make the pieces, stuff them with down, spread the down evenly, and sew a pattern similar to the Montbell's, in order to keep the down in place, and then stitch it together like normal? Or is that ignorant? I've never worked with down before, so I don't know what to do really. But I've heard the horror stories, so any advice would be much appreciated!


Edited by Niles on 01/09/2008 17:44:47 MST.

Lynn Tramper
(retropump) - F

Locale: The Antipodes of La Coruna
Re: Down pants on 01/09/2008 18:32:27 MST Print View

I don't know how MontBell manages to ensure the down is spread evenly in their garments. I own the UL down jacket, and have often puzzled over this question. I have made other down projects the traditional way (ie make a channel and then stuff a pre-weighed amount of down in each channel). Might be worth trying on a small test sample with some cheap throw-away fabric first. You can always rip open the fabric to retrieve the down afterwards.

Neil Bender
(nebender) - F
Quilting down on 01/10/2008 07:02:10 MST Print View

Some of old Frostline kits such as down vests filled main garments sections such as back panels and left and right fronts with down or polyfill edge-stitched in and then sewed the quilt lines later. This can be tricky as the insulation tends to push the inner and outer fabric layers around, and distributing down evenly can be tricky. If you overstuff this allows room for error, but doesn't use the down as efficiently.

Sewn threw garments don't allow maximum lofting of down anyway, so it may not matter. High fill (750+) down in garments often isn't much lighter than cheap 550 down. Using the lightest fabric is where the biggest gains are made. BPL found that out when prototyping the Cocoon tops. Polarguard only fills about 380 cu. in. per ounce, but in garments come close to down unless the garment has lots of loft and sewn in baffles.

You may want to consider 2 oz Climashield (replaced polarguard). With 1.1 ounce fabric you can build pants that weigh about 12 ounces that can handle moisture and only require stitching the insulation at the seam edges.

Al Baran
(FishBone) - F

Locale: Mid-South
Down LongJohns on 01/11/2008 12:02:34 MST Print View

Outdoor stores have inexpensive down longjohns used primarily for hunting you may want to consider rather than making your own. I got a set and modified the leg openings to remove the cotton blend stretch cuffs (just added binding). About 14 oz. total for size Med-Tall; probably 650 down. I used them once on a shake-down hike last year and they were delightfully warm, but haven't used them since. They're just gathering dust now; $25 and their yours.

Jeremy Cleaveland
(jeremy11) - F

Locale: Exploring San Juan talus
Re: Down pants on 01/12/2008 22:46:08 MST Print View

(I haven't made down pants, but did just finish some primaloft pants and have made a down sleeping quilt, and lots of other sewing.)

If you make up your own pattern try it on cheap fabric first and remember that adding insulation will change the fit. Otherwise, get a windpants pattern (I use's Liberty Ridge pants pattern). I'd recommend sewing plain old windpants first or something with cheap fabric to check the fit and get used to the process. are you looking to add baffles or just sew through for baffles? working with down is messy. Measuring down accurately is difficult, and I did a poor job of it. I set up a tent inside to keep the feathers contained then vacuumed up with a piece of no-seeum netting over the vacuum hose to clean up the down. using the mesh, I could actually use virtually all of the down.
after filling the chambers with down, try taping them shut and wait a couple hours for the down to fully expand so you can move the down around if you need to. I didn't do that and just sewed it shut, and now have some overstuffed in the leg area and some understuffed baffles in the torso area.

Have fun!! Down is a fluffy experience, but don't be too scared.

Casey Cardwell
(Niles) - MLife

Locale: On the Dirt in Oregon
Re: Re: Down pants on 01/13/2008 10:36:30 MST Print View

Lol. Thanks for he advice. I plan on just sewing through both pieces for the baffles. The two things that I'm most worried about is predicting the fit, and measuring the down.

I ordered the down from Ed Speer, so the project is a go. I have a pants pattern that I made up and am tweaking in the mean time for fit. Do you think that if the pants fit loosely all around, and are a bit long they'll fit fine when stuffed?

Thanks for all the help!

Neil Bender
(nebender) - F
Re: Re: Re: Down pants on 01/13/2008 11:05:48 MST Print View

If you stitch horizontal down compartments across each leg, the crowning of the fabric will definitely require that the unfilled pattern be longer because the fluffed down will shorten the pants. A 30 inch finished inseam might need 33" plus seam allowance for cuff hemming if you fill them really puffy. The down will require some additional circumference over an uninsulated wind pant, but again it depends on how stuffed the pants are. If you cut them too big you can always trim them down later, which is easier if they aren't over filled. You can just shake the down away from the stitch line pin the down back, sew a new seam inside the old seam to shorten or tighten the pattern, then trim excess fabric and finish the seam.

It also depends on how nicely you want them to fit. Around camp clothing can be fairly crude and still function OK.

Jeremy Cleaveland
(jeremy11) - F

Locale: Exploring San Juan talus
Re: Down pants on 01/13/2008 21:40:27 MST Print View

primaloft pants

here are the complete primaloft pants for inspiration: Momentum shell and liner, 0.6" of primaloft sport, and full #3 molded tooth side zips. 11 oz on the not so accurate spring scale.

For fit, I made each of the 4 panels wider on the outside (where the zippers are) by 1.5" per panel, so for each leg it was 3 inches more in circumference, which is only about 1 inch more diameter. do not add width to the inseam and crotch seam since that might mess up the fit, especially in the hip area (ie adding an inch all the way around each piece would be 4 inches wider in the legs, but above the crotch it would be 8 inches wider. Not good.)

I then proceeded to check the fit and trimmed off about half an inch of the 1.5" I added, so it has an inch extra (on the outside edge of each panel, for a total of 2" extra diameter per leg). I also sewed the crotch seam a little narrower.

*** this was done for a looser fit that could fit over winter clothing for backcountry skiing, so they could fit smaller for pants that get used mainly for in camp at night

Casey Cardwell
(Niles) - MLife

Locale: On the Dirt in Oregon
Re: Down pants on 01/13/2008 21:58:58 MST Print View

That's great, they look really good. I'm officially inspired. The changes you made to your pattern are really helpful.

Thanks again!