Mar 23, 2012 at 9:28 pm #1287731
I'm begining my ultralite and myog journey with a quilt. I have some questions for all the experieced quilt makers out there. My quilt will be a tapered (42" top, 36" bottom) and 67" long. I will use the M50 and 900 fill down from Thru-hiker.
For Australian conditions I only need something around 45-50 degrees. On the Thru-hiker site one article suggested 1.5" loft for 40, 2.5" for 30, am I right in assuming that 1" loft would be ok for 45 degrees?
If I also use the width x length x height /fill power formula on the Thru-hiker site then the amount of down I require is 2.90 ounces. Does anyone see any problems with this figure?
I am going to have sewn through baffles (for ease of sewing) but I really have no idea of size for a 1" loft. Any thoughts?
Thanks in advance for your help,
RoannaMar 23, 2012 at 10:48 pm #1858544
> For Australian conditions I only need something around 45-50 degrees
You had better say what State you are in. That might be OK for Darwin. For NSW, Vic and Alice Springs I have seen sub-zero – in the Autumn.
> the amount of down I require is 2.90 ounces.
That's about 82 g. Yeah, I see a HUGE problem with that! I suggest something like 300 MINIMUM, more like 400+ g. I suggest you check your maths.
> sewn through baffles (for ease of sewing)
Lighter, easier – and cooler.
(Sydney, Oz)Mar 23, 2012 at 11:10 pm #1858548
Thanks for your input Sydney oz,
I live in Queensland and in summer/ autumn temperatures rarely fall below 10 degrees celcius (50 F) where I walk. I already have a light winter bag but it is too hot for summer/autumn.
Using the my dimensions and a 1" loft of 900 fill power down, the volume of my bag would be 2652 cubic inches divide that by the 900 and I get 2.9 ounces of down. This method came from an article on quilt making at thru-hiker. If there is a better method of working out the amount of down needed I'm interested.
More importantly I'd like some input on whether or not my asumption 1" loft for 45-50F temperature is ok.
Cheers.Mar 24, 2012 at 2:09 am #1858564
I think the 1.5 inch baffle height that appears in the Thru-hiker article is assuming that you sew in 1.5 inch baffles made from netting. It is not intended as a starting point for a sew through quilt design. For one, you will use less down, because your sew through baffles will be ellipsoidal, as opposed to (roughly) rectangular (in the case of the thru-hiker quilt). I have only modified a sew through bag into a quilt so far, so I cannot help you with fill calculations. The received wisdom is to overstuff by about 30% I believe. I did your calculation and got the same answer, so I don't know whats going on there really. 82 grams is clearly not enough. Suppose your shell weighs 150 grams, add 300 grams of down, you end up with a 450g quilt. That sounds about right for 45°. Whatever you do, remember to use a vacum cleaner, some cardboard tubes, and organza netting to handle the down. Do not attempt to stuff the bag by hand!!! You load up a tube with down, put it in the baffle, hold down the material around the tube and blow. For what it's worth, I think sew through is a good idea for a warm weather quilt, as it saves alot of weight. I added velcro tabs to my quilt, so I can attatch my down jacket (also with tabs added) to the top. This helps reduce cold spots, add warmth, and means my jacket doesn't keep slipping of during the night.
MattMar 24, 2012 at 2:58 pm #1858752
I have made many quilts and sleeping bags, so I have some idea of what works. There are MYOG articles here at BPL on this.
First of all, '900 FP' is a bit of a joke in the trade – some say 'fraud'. It's nothing like that in the field. In the field the down never fluffs up as much.
I would suggest 300 g of good down would be enough for Qld. Yes, there will be some nights when you can sleep on top of your bag instead of inside it. You could drop down to 250 g if you have thermals on, some nights.
CheersMar 24, 2012 at 5:20 pm #1858814
Thanks for the responses.
I think I'll order 6 ounces from thru hiker and see what happens. I always take a set of thermals even in summer. I can always take my MH phantom 32 if it looks like the weather will be poor (thats 40F most places in Autumn). I probably should make the quilt so it could fit over my phantom bag and take both for below freezing conditions.
Would 5" spaced sewn through baffles be ok?
I have also seen some bags with squares. Could I go 7"x5"?
CheersMar 24, 2012 at 5:33 pm #1858820
@b-g-2-2Locale: Silicon Valley
"Would 5" spaced sewn through baffles be ok? "
That 5" is about the right spacing for that temperature range. I guess you know that sewn through baffles are much easier to sew, but they are much less efficient (feels colder) than regular box baffles.
–B.G.–Mar 25, 2012 at 2:16 am #1859041
5" should be OK, although 6 oz migh not fill them very well.
Double layers work well. Recommended.
> some bags with squares.
Extremely difficult to sew.
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