measuring down

Posted by: TurkeyBacon

measuring down - 06/28/08 05:36 AM

So my situation is a bunch of recycled down from thrift store comforters and as of now, no nylon or pattern. The nylon and pattern will come with time. The goal is a summer bag.
I'm thinking about using .5 inch no see um netting baffles to make it nice and puffy. Since my down has no loft rating and is not very high quality, I was thinking about figuring out roughly how much cu. in. I need and just making a cardboard measuring devise and just measure my down by volume, instead of weight. Does this make sence? Should I include a fabric lid to simulate the weight of the fabric in the finnished product?
Posted by: lori

Re: measuring down - 06/28/08 07:28 AM

I do believe you measure down by weighing it. You'll need a good digital scale you can zero out and a container for the down. Weigh the container, zero out, and put in down until you have the ounces required for your application. I have never seen down measured in cu. in. It sounds impossible.

Beware of recycled down - it's probably a lot less warm than new 800 or 900 fill power down. It probably has less loft and more feathers to work their way through the shell material. I don't know if it's worth the effort to try to harvest down from old comforters - I thought about it, but visions of chasing fluff around the room - yikes. If you've never worked with down consider that it gets EVERYWHERE. Some do it yourself instructions I've seen say to sit in your closed tent in your living room to avoid coating all your belongings, and prepare to be coated yourself. It would only be a "deal" (IMO) if you were picking up the old comforters for less than ten bucks apiece, which I guess is possible in a thrift store.... To me, it would be worth it to get premeasured portions for a little more money over which I could keep better control of the stuff - Speer sells high quality down for twenty six bucks per 3 oz bag. (scroll down to the bottom) There are other places like Thru HIker that sell down or a down quilt kit. If it were me I'd buy a kit from Thru Hiker for $150 and have a nice Momentum and down quilt.
Posted by: TurkeyBacon

Re: measuring down - 06/28/08 12:36 PM

I am fully aware that this sl bag will not be first quality, but its a summer bag so thats OK with me. I have ripped a small hole in both comforters and am amazed just how little feathers are in the down. I beleive I got lucky. I realize its still probably 450-550 power fill, but like I said, it will be in a summer bag so high quality down is not a requirement. The lack of quality down is also why I'm willing to try something other than the status quo for measuring the amount of down. First I would have to figure how what fill I have, then weigh it out. Since I do not have a digital scale I'm hoping to find an alternative.
I have made some very high quality products, this will not be one of them. I'm ok with that.
Posted by: TomD

Re: measuring down - 06/28/08 04:44 PM

Fill power is figured out by dropping a measured weight into a tube of down filled with one ounce and then measuring the volume. There are pictures showing how this is done on the web. Search under fill power or down, something like that.


If you go to WM or FF's websites, they tell you how much down is in each of their bags. You could use that as a comparison, even if the down you have is lesser quality.
Posted by: DJ2

Re: measuring down - 06/29/08 09:20 AM

Burton's Man In A Cold Environment says the following thicknesses are required for the temps indicated.

Degrees Thickness
40 1.5"
20 2.0"
0 2.5"
-20 3.0"
-40 3.5"
-60 4.0"

Thickness is measured from skin to outer layer of sleeping bag.
Posted by: TurkeyBacon

Re: measuring down - 06/30/08 03:31 AM

Interesting weekend. My digital camera is broke or else I would include pics. My semi-scientific results are that my down is 600 fill. The semi part comes from the fact that my scale is not overly accurate. I weighed out 1 ounce and then put it in a 7x7x20 cube that I made and measured how high it was.
The biggest discovery was that working with down is a serious pain in the butt. I think I came up with a method for working with it.
Now time for getting materials and making a pattern.
Posted by: finallyME

Re: measuring down - 06/30/08 11:43 AM

I think DJ has a good idea. Instead of measuring the weight, just figure out the thickness you need, and stuff until you reach the thickness.
Posted by: TurkeyBacon

Re: question on loft numbers - 06/30/08 12:17 PM

When people give out numbers on loft, are they talking about one layer of the bag or both. For instance, my summer bag apparently needs to be 2 inches thick. Is this two one inch layers or two two inch layers?
Posted by: jonnycat

Re: question on loft numbers - 07/01/08 09:37 AM

When people give out numbers on loft, are they talking about one layer of the bag or both. For instance, my summer bag apparently needs to be 2 inches thick. Is this two one inch layers or two two inch layers?

Normally the loft of the whole bag, top and bottom, sitting on a hard and level surface, and having been given sufficient enough time to loft.
Posted by: Paul

Re: question on loft numbers - 07/04/08 01:24 PM

Actually, there are two convetnions to be aware of. Bags are usually described in terms of total loft - the fluffed-up bag laid on a flat surface and the total height measured. On the other hand, Charts that show how much insulation is required for a given temperature usually refer to a single layer - so if the chart recommends 2" of loft for the temperature you want to be comfortable in, you need 2" of loft above you, or roughly 4" of total loft. f course, all the reccomendations for amounts of insulation have to be interpreted by you for your own needs - you may sleep warm or cold.
Posted by: jacket_inserts

Re: measuring down - 07/16/08 01:23 PM

There have been various threads in the past about working with down. I haven't used a tent myself and would be leery of it because of the static electricity interactions between the down and the tent and sleeping bag fabrics.

What I did was clear and clean up about 6-8 m2 of space on a carpet and work slowly so that the loose down settles and gets caught on the carpet (and on the down that's already on the carpet) as opposed to flying all over the room. Once you're just about finished, you can collect the down from the carpet (and from your clothes, hair, etc.) with a vacuum cleaner hose covered with a couple of layers of no-see-um (pick off the compressed down from the netting frequently if you don't want to fry the vacuum cleaner).

Posted by: BarryP

Re: measuring down - 07/16/08 02:12 PM

“like that.

That’s a very enlightening link. Thanks Tom.