I beginning to toy with the idea of sewing up a cold weather down bag, I think I understand the construction of just about everything except how to end the baffles. What I mean by that is that I understand how to attach the baffles to the inner and outer fabric, but where I'm stuck is how do you then attach that to the right and left sides?

I've searched through a number of threads here and on other sites and haven't found any explanation of this part. Pictures would be an incredible help.

Also, I know that most baffles are sewn in, but is it possible to use some sort of adhesive to bond the baffles to the inner/outer fabric? I feel somewhat comfortable in my sewing abilities but this will definitely be the biggest project I've ever undertaken, and anything I can do to make it easier is just fine by me.

Do you mean how to join the ends together? If the seam is on the bottom, it doesnt matter too much because you'll be laying on it; a french seam works fine. If it's on the side, sew the shell from the inside (right sides together), then sew the liner with the edges tucked in (wrong sides together with the edges folded in towards the middle).

Roger's article has some pictures, including a diagram of what I described

http://www.backpackinglight.com/cgi-bin/backpackinglight/MYOG_down_quilt_bag#.USgImePZ_-s

I have some other stuff on my blog but don't specifically address what I think you're asking

http://outlivingblog.wordpress.com/2012/12/03/mummy-bag-construction/


re: adhesive for baffles, I suppose you could, but it'd probably be more difficult than just sewing it and a lot heavier. They're just big straight lines and if they're not quite straight it doesn't matter. Draw lines and follow 'em.

Edited by brendans on 02/22/2013 17:39:00 MST.

I see what your question is. I agree, Roger doesn't really show what he does on ends, although you can see from the first pictures in his article, which is to just sew the front and back together.

I am a novice, but when I did it, the baffles go all the way to the end so they just sort of wrinkle up there and there's actually a gap that the down could theoretically flow between baffles, but in actuality, it doesn't.

I've been experimenting with just doing sewn through baffle, but having the inside fabric spacing an extra 1.5 x the baffle width (actually pi / 2):



Then, at the end, have the liner fabric and extra 0.75 x baffle width longer:





Just fold it over to consume the extra 0.75 x baffle width. Maybe you can see from thos pictures.

Maybe you could do the same thing with conventional baffles to have the loft go all the way to the end.

One other picture

You don't need to finish off the ends of the baffles - let the down flow, 'cause it won't. It also lets you redistribute the down should you decide you like having more over your chest than your thighs - just sweep the bag with your hand and some down will squeeze through the end gap.

Besides, it gives you a sneaky way to stuff your down with only a single small hole - run a paper tube (think mailer) through all those end-gaps to the furthest chamber. Stuff your measured down into the tube, ramrod it through, and retreat the tube into the next chamber. Repeat 'til complete. Heckuva lot easier than dealing with the entire side of your project open, taping it to the edge of a table, etc...

@Brendan

Thanks for the links unfortunately Roger's article is in the members only section so I'm unable to view it right now. The Mummy bag you linked to was outstanding.

My question was more or less answered by Jerry and Nathan, but it was more dealing with how do you finish off the edges of the baffles. On your mummy bag did you run the baffles all the way out to make fully separated tubes or are they connected at the end?

Excuse the crudeness of the drawing but here is what I mean. the black and blue represent the inner and outer shell and the purple represents the baffle.

By any chance you wouldn't have any kind of pattern for that mummy bag you built do you? if not, does anyone know where I could find a pattern to get me started? I'd feel more comfortable going into this project with a better idea of how to build complicated bits like the hood if I had some kind of pattern to follow.

> Roger's article is in the members only section
That problem is easily solved ... :-)
Could even be worth the investment if you are serious about gear and MYOG.

> how do you finish off the edges of the baffles.
I ran the baffles as close to the edges as possible, then closed the edges. The baffle compresses of course - but so what?
Your right hand diagram leaves far too big a gap at the end of the baffle.

Cheers

@Roger
I've certainly considered the membership a number of times, unfortunately now isn't the time. Any BPL membership, or this planned sleeping bag for that matter, are probably a few months away until some other things are paid for.

as for the baffles, I guess I was worried that I needed to keep the full loft of the baffle all the way to the edge or I would end up with a cold spot all along the side of the bag. On the zipper I will have a draft tube to add insulation in this area. But on the non-zip side how do you prevent a lack of insulation where you sew the top and bottom together if both top and bottom baffles have been compressed at the edge?


One other question, I've noticed that a select few manufacturers remove most of the fill from the back side of the sleeping bag and add it to the top. The theory is that when you lie on it you compress the down anyway, so it is more effective if it is on top of you. I do have a Exped Downmat UL7 which I've yet to test in cold conditions but is rated rather well for insulation. Is this practice of putting more fill in the top than the bottom wise?

Thanks Roger and everyone else for your sharing your advice and your experience. I never even considered myog projects until I found the forum,

"Thanks Roger and everyone else for your sharing your advice and your experience. I never even considered myog projects until I found the forum,"

I suggest you not join and quit this MYOG thing immediately before you get hooked : )

The down sort of pushes out the front and back side resulting in the edge where they join actually being pulled in a little so there is a minimal cold spot.

Some down bags have a tube filled with down running along the edge inside the bag to cover the cold spot.

Jesse,

I think I understand what you are asking. Could you do continuous baffles like WM to avoid the problem? Then each end of your baffles end at the zipper(on opposite sides). There would be no second cold spot this way, only at the zipper which your draft tube would handle. You could also put in a side baffle on the side opposite of the zipper, but probably not necessary unless you're looking at a <0 degree bag.


Ryan

Edited by ViolentGreen on 02/23/2013 09:32:56 MST.

Jerry,
I'm afraid it's too late, I've already fallen down that rabbit hole.

@ryan
I may be biting off more than I can chew here but that temp range is exactly what I'm going for. I have a great down summer bag that should last me a while yet. Where I lack is in my winter gear. I have a forever old Peak One (Coleman's ancient high end brand) synthetic bag. It's heavy and it doesn't compress well, though it is very warm.

I'm looking at trying to make this somewhere in the neighborhood of -10 to -15f.

I've seen some of the bag mfgr's use a v baffle that runs the length of the non-zip side, I'm thinking that may be an option here.

Edited by jeepin05 on 02/23/2013 08:55:45 MST.

It's going to take a LOT of down for a -10 bag. A much easier and cheaper route would be a synthetic overquilt to use with your summer down bag. A quick glance at a FF -10 bag uses 32 oz of fill. That's $$$$$$$$ and complicated things like draft tubes and differential cut start to matter a lot more. A synthetic overquilt will manage moisture better and take a fraction of the time to make. I've used a 2.5 oz climashield apex quilt over a 20* down bag down to -20 F with extra clothes.