Questions On Sewn Through Baffling On A Quilt.

[headchange4u]

I was looking through the JRB website last night, hoping that the 8x8 tarp tent was gonna magically appear on the site, ready to order , when I noticed that both the JRB Stealth and the Shenandoah both use sewn through baffles instead of netting baffles like thicker quilts. Both quilts have a loft of 1.5" and are rated for 40-45* on the JRB website.

That started a spark of thought that turned into a 5 alarm brain fire that kept me up until about 2:00 am.

I also remembered that the Western Mountaineering Megalite and HighLite both use sewn through baffling. The Megalite is rated at 30* and has a 4" loft and the HighLite is rated at 35* and has a 3.5" loft. The loft measurements are probably for the total thickness of the bag, counting the top and bottom, so you are probably looking at about 1/2 the loft of just the top section of the quilt (2" for the ML and 1.5" for the HL).

I own the one-of-a-kind JRB ultra light Nest and No Sniveller and they have netting baffles that are 1.5" and I think Pan said they are rated at about 40*, but from my experience with these quilts, that temp rating is a little conservative.

My main question is at what temperature or loft does sewn through baffling become ineffective? At what point do you need to forget about sewn through baffles and switch to using netting baffles. Using sewn through baffles would be a pretty quick and easy way to make a 2.5 season quilt,IMHO.

Another question that came to mind about construction. Do you sew the baffles through the quilt first and then stuff with down or you you sew the edges of the quilt, try to evenly distribute the down and then sew the baffles? I guess sewing the baffles first would be the only way on insuring that the down is even in each baffle.

[slowhike]

good questions. i've wondered about the very same things. looking forward to hearing comments.

[txulrich]

When I made my quilt, we sewed the baffles to the top and bottom layers, then sewed one side. Next, the down was inserted and the side was pinned as each chamber was filled. Then the last side was sewn and the attachment loops, draw cord, cord locks and the hook and loop material were added.

If I were making a sewn through quilt, I would follow the same process. Just sew the top and bottom layer together rather than use netting.

Another question that came to mind about construction. Do you sew the baffles through the quilt first and then stuff with down or you you sew the edges of the quilt, try to evenly distribute the down and then sew the baffles? I guess sewing the baffles first would be the only way on insuring that the down is even in each baffle.

[headchange4u]

When I made my quilt, we sewed the baffles to the top and bottom layers, then sewed one side. Next, the down was inserted and the side was pinned as each chamber was filled. Then the last side was sewn and the attachment loops, draw cord, cord locks and the hook and loop material were added.

If I were making a sewn through quilt, I would follow the same process. Just sew the top and bottom layer together rather than use netting.

The only reason that I ask is that I bought a down lap quilt at Walmart on clearance for $7 (It really contains down, not feathers. I wish I had bought all they had now.). It is a sewn through box baffle design and I can feel that there is down in the areas of the stitching. I guess that's the cheapo WM construction for you.

[Coffee]

I haven't made a sewn through one yet. I don't think one is in my immedate future.

My thinking against is the weakest link in the chain concept. You are only as warm as the thinnest spot of insulation. Ideally at the sewn through baffles there is no insulation. So you would not be warm right there. In practice this isn't true. The baffles to each side would provide some insulation. The heated dead air space between you and the quilt would also help to warm those spots.

If I was to make a 1.5" think quilt I would still use baffles. IMHO you get a warmer quilt with only the added work of sewing in the baffles. Probibly an oz or 2 weight gain if that with noseeum around an 1oz per square yard.

Having said that the down jackets with sewn through baffles seem warm. After I get a job and some money flowing in I am going to order the down jacket kit from thru-hiker. If it doesn't have it I am going to talk to AYCE about adding baffles. It will make it harder to sew, but that is half the fun. It should make it even warmer.

I would definitly sew the baffles first and calculate the down needed from there.

What size baffles is everyone using? Looking at my UQ I am thinking about using larger baffles. I have one foot end with a 10" wide baffle. It seems to loft more with proportionally the same amount of down. I think if I get the chance and order enough extra down on my next balk order I will make one using walmart fabric with different spaced baffles to test out the widths.

Also has anyone made one with cross baffles? My montbell bag has that. I seem to have a lot of issues with the down shifting in my UQ. Cross baffles would be harder and add a lot of sewing time, but once again that is half the fun.

[headchange4u]

What size baffles is everyone using? Looking at my UQ I am thinking about using larger baffles. I have one foot end with a 10" wide baffle. It seems to loft more with proportionally the same amount of down. I think if I get the chance and order enough extra down on my next balk order I will make one using walmart fabric with different spaced baffles to test out the widths.

When I make my quilt I am going to be using 8" wide baffles simply because my quilts is going to be 50"x80" and 8" baffles are just a nice round number that divides evenly into 80"

[BillyBob58]

That is a darn good question. I have noticed over the years that many bag manufacturers seem to consider a change in loft of 1" ( total, top/bottom) to be equal to about 10° warmth. I notice that your two examples have 1/2" loft diff and have 5° dif per WM's rating. Now that is with no baffling confusing the issue. Although, at the WM website, it shows the Megalight has actual baffles, and is not sewn thru? Is yours an older model that was sewn thru? If so, it just makes the comparisons a bit easier, because the baffled model at their web site still is rated for 4" loft and 30°. So, 1" loft dif still makes 10° dif ( or in this case 1/2" still = 5°), with or without baffling being added to the warmer model.

As you go down the list at the WM site, with other models that are baffled, the pattern holds the same. As long as features like collars and girth are accounted for, in the same "series" of bags- 1" loft seems to make the same 10° dif in the other bags baffled or not( although, there are not many with out baffles to compare to ).

The sewn thru Linelite has 2.5" loft ( 1" less than the 35° highlite) and is 10° cooler at 45°, though intended to be used as a liner where lack of hood would not effect the rating so much. A Tamarck WITH baffles is 4" and 30°, just like your Megalite. The baffled ultralite Super is 5"=20°. Adding 1" loft PLUS baffles still made only 10° dif. The Versalite Super is 6" and 10°, with baffles.

Again, sleeping bag size, fabrics and construction can all make a 5-10° dif at the same loft. But I'm starting to wonder exactly how much baffles really contribute to raw warmth rating, as opposed to just giving better control of down and more consistency. I always thought it made a big dif, but now I'm wondering. Though importance of control of the down is not to be dismissed.

Here is another question to go with your original questions. How much do baffles weigh, and how much does adding them to a bag cost? In other words, a sewn thru bag with an extra 2 ozs of down vs. a baffled bag with less down- which would be warmer in the field, or weigh less or cost less, with all other things equal?

I figure there is someone here who knows the answers.

Bill

[Coffee]

That is a darn good question. I have noticed over the years that many bag manufacturers seem to consider a change in loft of 1" ( total, top/bottom) to be equal to about 10° warmth. I notice that your two examples have 1/2" loft diff and have 5° dif per WM's rating. Now that is with no baffling confusing the issue. Although, at the WM website, it shows the Megalight has actual baffles, and is not sewn thru? Is yours an older model that was sewn thru? If so, it just makes the comparisons a bit easier, because the baffled model at their web site still is rated for 4" loft and 30°. So, 1" loft dif still makes 10° dif ( or in this case 1/2" still = 5°), with or without baffling being added to the warmer model.

As you go down the list at the WM site, with other models that are baffled, the pattern holds the same. As long as features like collars and girth are accounted for, in the same "series" of bags- 1" loft seems to make the same 10° dif in the other bags baffled or not.

The sewn thru Linelite has 2.5" loft ( 1" less than the 35° highlite) and is 10° cooler at 45°, though intended to be used as a liner where lack of hood would not effect the rating so much. A Tamarck WITH baffles is 4" and 30°, just like your Megalite. The baffled ultralite Super is 5"=20°. Adding 1" loft PLUS baffles still made only 10° dif. The Versalite Super is 6" and 10°, with baffles.

Again, sleeping bag size, fabrics and construction can all make a 5-10° dif at the same loft. But I'm starting to wonder exactly how much baffles really contribute to raw warmth rating, as opposed to just giving better control of down and more consistency. I always thought it made a big dif, but now I'm wondering. Though importance of control of the down is not to be dismissed.

Here is another question to go with your original questions. How much do baffles weigh, and how much does adding them to a bag cost? In other words, a sewn thru bag with an extra 2 ozs of down vs. a baffled bag with less down- which would be warmer in the field, or weigh less or cost less, with all other things equal?

I figure there is someone here who knows the answers.

Bill

If I remember right I added 1.5" to the width of the baffle to get a roll seam of sorts on the end. That would make each baffle for a 1.5" think before overstuff 3". With 7 sewn in baffles it would mean 21" of width, by around 48" wide. noseeum is either 1.1 or 1 oz per square yard, nanoseeum is around .7oz per square yard. That would mean around an oz when everything is all said and done. Probibly only add an hour or so to the construction time.

If you are figuring the same loft it should use the same amount of down. If it helps the weight difference between my 2.5" loft and 3.5" loft is around 4oz, the 2.5" does have extra material on it for a headhole adding around an oz.

[Mule]

I have seen cross sections of sleeping bags years ago that were sewn thru BUT two layers, the seams staggered so that where you have the most loft in one layer of sewn thru construction you have the seam of the other one sewn through. Using 1.1 oz fabric, that would only add about six ounces max to the overall weight,
NOW FOR THE GOOD PART: If you made two quilts and staggered the seams in this manner, ( Start the say 6 " seams on one at 6 inches and start the 6 inch seams on the other at 3 inches)you could NOT sew the two together, rather, VELCRO the outside edges together to make a summer/winter Quilt, of two summer quilts. That is the way I am going to make mine when I make my quilt.
Mule

[headchange4u]

I have seen cross sections of sleeping bags years ago that were sewn thru BUT two layers, the seams staggered so that where you have the most loft in one layer of sewn thru construction you have the seam of the other one sewn through. Using 1.1 oz fabric, that would only add about six ounces max to the overall weight,
NOW FOR THE GOOD PART: If you made two quilts and staggered the seams in this manner, ( Start the say 6 " seams on one at 6 inches and start the 6 inch seams on the other at 3 inches)you could NOT sew the two together, rather, VELCRO the outside edges together to make a summer/winter Quilt, of two summer quilts. That is the way I am going to make mine when I make my quilt.
Mule

I kinda had the same idea of coupling a summer quilt with a small loft with a normal 3 season quilt with a larger loft to make a winter quilt by combining the 2.