DIY half bag

[perfectlydark]

Very nice work!

[Bluegum Mic]

Another amazing bag Mike. You seriously need to go into business. Your quilts are amazing. I love mine

[undercling-mike]

Thanks guys, I'll reserve judgement on the bag until Moondog has a chance to test it but I thought it was an interesting project to take on. At the moment I seem to be able to make about 1 item per month so it's not much of a business proposition unfortunately.

Mic did you have the chance to properly test your quilt yet?

[Bluegum Mic]

Ive tested it, love it, but not yet pushed its temp boundaries as we had quite balmy nights.

[Mickl]

At the moment I seem to be able to make about 1 item per month so it's not much of a business proposition unfortunately.

That's 12 quilts that don't need to be purchased from overseas! Australia Definitely needs a cottage quilt maker. If your quilts were are good as certain other companies and they certainly look it from the photo's I'd happily buy one when I needed instead of getting one overseas! Obviously I don't expect you to say the exact $ amount in a post but would the price you are able to sell them for be similar to ones available online?

[Moondog55]

The half-bag arrived this morning and I am seriously impressed with the quality of the work. I have skinny legs and this tailored fit is perfect and the length is spot on. As discussed with Mike the fit is to the waist and it fits inside the outer synthetic bag with just enough room to loft fully
I'm another one who will happily endorse Mikes work
Anybody else who wants a lightweight winter booster should look at a similar half bag
Mike I know I've paid what was discussed but I'm going to adding a little extra as I think you work is worth it

[Moondog55]

Pictures here

viewtopic.php?f=15&t=19408&p=262176#p262176

[stry]

How long should a normal half bag be MD ??

I understand waist length suits your requirements for a booster/inner, but thought more length would be desirable if used on its own. Armpits ? Mid-chest ?

Obviously too long defeats the purpose of the idea. Too short and a cold gap easily appears between top of bag and bottom of jacket.

PHD simply says "one size fits all".

[Moondog55]

PHD are often wrong. One size will fit most but not perfectly.
When used alone Mid-chest is a good length and Feathered Friends do 3 different lengths because of this but as a liner bag I only wanted to insulate my long skinny legs, therefore a bag cut to fit the fabric width sewed up perfectly at 1300mm.
Somebody taller than my ~1840 would probably want it to be longer.
I try and buy jackets that come down to my crutch also, if you prefer the shorter type of insulated jacket then obviously the half bag needs to match up by being longer.
The main advantage of Mikes work was getting the skinny cut; it save weight and minimises the amount of dead air that needs warming

[Moondog55]

Another useful attribute of the skinny and shorter half bag is for use by younger walkers. I can see this half bag making something like the Katmandu Pipsqueak kids bag usable for winter camping

[stry]

You piqued my interest a little, as I recall at least one occasion when I was tent bound with my bag pulled up under my arms and dozed off for a very comfortable and cozy snooze.

You got me thinking that maybe I could plan on doing this and save some weight and space. Unfortunately, as my tired hard drive spun a little more, I recalled that those experiences were in a J&H Winterlite, and wearing thermals, one (maybe two) fleece(s), and a WM down jacket.

So maybe not a valid comparison

[Moondog55]

As you say not really a valid comparison but perhaps if this was my WM Tamarack it would be.
It would be an excellent way of getting a 3 season quilt usable in snow however; provided the down parka was warm enough. but for that you need the standard cut so the half bag pulls over the parka at about mid chest

[stry]

You are a nuisance MD

I just looked at the FF Vireo. Nice and slim around the legs, much more so than PHD or WM. Sufficient girth for me in a jacket. More down lower down (smart). Choice of lengths.

The shortest would come up to my armpits, so I could tuck my hands in if needed.

Very tempting !!!

[Moondog55]

You are a nuisance MD

Very tempting !!!

ROLF

I wasn't trying to be. 'But that combination with a quilt is used by a few walkers Stateside I believe I did seriously look at the Vireo myself but got the Tamarack at great price as it was a sample brought in by Paddys and got sold on eBay at less than cost

[Moondog55]

Shame you can't make the Glamping WE as I'm bring all this stuff as part of the Show & Tell

[stry]

Yes - I was looking forward to it but ..............

I have a new syndrome for the forum - MMTS Syndrome. It's akin to GAS and stands for "More Money Than Sense"

The afflictions are synerginistic.

Given that I may be coming down with a bout, and given that we are wandering nicely away from DIY, would you be attracted to the Vireo UL or the Vireo Nano ?

My thinking is that given that my use would be as a stand alone bag, and not used with my usual liner, I would perhaps prefer the apparently more robust fabrics of the Nano, and pay the 50gram penalty.

Appreciate your (or anyone's) thoughts.

[Moondog55]

Start a new thread in Equipment
Heavier would be my choice 50 grams isn't much in the scheme of things

[undercling-mike]

I just got back from a trip so I'm really happy to hear that MD got the bag and is happy with it. Hopefully we'll get some field reports once he has the chance to try it out.

I'll just add some thoughts about booster and half bags. During the course of making MD's bag I was thinking about whether I would want to make something similar for myself and what purpose it would serve. As a booster to be used with an appropriate puffy jacket I think the dimensions of MD's bag are about right. It will overlap the jacket enough to prevent drafts or cold from creeping in while being minimal to reduce size and weight. If it was made with Argon 67 or equivalent instead of Argon 90 you could save around 30g, making a ~225g item. That's pretty light but starting with a bag/quilt that is warm enough would be more weight efficient in theory (assuming similar quality down/fabric), of course most people don't have the luxury of owning many quilts/bags to cover all the temperature ranges they might encounter and the booster approach gives some flexibility in that it doesn't have to be used if the weather is warmer than feared. It could also be used by different family members if they are going on trips at different times or be given to another member of a group if they are struggling and suffering more than others.

The other scenario I could imagine using a half bag is for alpine climbing where you will probably encounter awkward seated bivys (not something I do). At least for the case where you are fairly certain of bivying I'd be tempted to make the bag longer and wider at the top to allow it to go over the shoulders (like the FF vireo), you would also want more loft of course and the differential fill to optimise use with a down jacket, like the Vireo, is probably smart too. My take on these systems is that they are for situations where you are right near the temp rating or probably below it as if you're alpine climbing you need to really minimise weight/bulk and have drafts sealed out if you end up sitting. There isn't any real options to vent if it's too warm, for general bushwalking or camping I'll be sticking with quilts.

[Moondog55]

The secondary use as a kids bag also has great merit. It's only my opinion of course but the best use of the half bag may be to extend a 0C quilt into the depths of winter using an appropriate top layer; as very few of us own or use an expedition cut bag that has enough room inside for a liner bag
I do of course but such bags are quite specialised
Any more fill than the 130grams in mine and I agree with Mike that a baffled differential bag would be much better

[undercling-mike]

Just to respond to the other comments about having an Aussie quilt maker; I think it would be possible given the current AUD/USD exchange rate, I think you would need to set up production with enough volume to get decent bulk discounts on materials. It goes without saying that you'd need to optimise the design for ease of construction and streamline production (probably standard sizes versus custom). You would also need very low overheads on production (e.g. hire sewers who work from their own homes). I think there's probably just enough of a market to get to the required volume provided your marketing is good enough. Prices would likely be similar to US cottage manufacturers after exchange rate conversion I think but hopefully you'd save on postage.

It'd be quite a risk to set it up and a lot of work but that's no different from any other small business. For my part I've got a few items lined up for family and friends (as well as personal projects) but I may be able to take on a few custom projects as time permits.

[undercling-mike]

A kids bag would also be a good secondary use Moondog. It'll be interesting to see how much extra warmth you get out of it. I think we chose good specs for a booster bag because the more loft you want the booster bag to have the more space you need inside your regular bag. Your half bag would probably use all of the room in most efficiently cut sleeping bags (or the footbox of most quilts).

[Moondog55]

I think so; although it is much smaller than the outer bag, the outer bag isn't a slim cut except in the shoulder region and that is due to making that bag as cheaply as possible at the factory
I'm going to try it out next week-end at the Mt Franklin gathering. We should get down to around 5C at night there so a fair enough test. As for being a cottage manufacturer only worth while if you can get the materials at the best possible price so need to be cashed up for full roll purchases and have enough sales of at least one/two stock items to cover the basic costs.
A while ago some-one in America was producing a dedicated kids bag the had the half bag function as an added bonus as the kids got larger but I can't remember which larger maker it was, probably Gerry as he did a lot of dedicated childrens gear, including pushers and kiddy carriers

[Moondog55]

Are you still taking orders Mike? PM inbound as the Boss needs something extra warm but relatively lightweight

[Moondog55]

OK An update
I only got to use it once apart from my nite in the back yard, sadly I have to report that it wasn't as warm as I would have liked; although a lot of that is down to me being cold and tired when I went to bed.
I think for this to be a realistic survival aid without the other Thinsulate bag as well I need some extra warmth
I'm got some synthetic insulation from Simon a while ago and I think that adding a layer of that over the down half bag would give me another 5 to 10 degrees of insulation and add less weight and mass than the full Thinsulate bag and that will allow me to carry the DAS parka which is a better solution to the possible problem
Mike how many meters of Argon did you need to sew this up; 2 or 2 and a half? I'll order it and get stuck in as soon as I've finished the kitchen and Ceciles new workroom

[undercling-mike]

What were the conditions like when you used it? Did you try just half bag plus parka? I'd think something like 10C would be the rating in that use, although it depends a lot on the user and their condition of course. I notice the phd alpine ultra half bag (which has maybe a bit more loft but not much) is given a 'typical operating temperature' of -5C. That must be the total shivver bivy rating for hardened mountaineers.

Anyway, if I understand your plan you're thinking of sewing a layer of synthetic insulation (2.5 apex?) and Argon fabric to the outside of the bag. Looking back on my notes I used just under 3m to make the bag, but that's shell and liner so for a single extra shell you should need about half that, maybe slightly more if you want to make the outside layer a little looser.

[Moondog55]

Yep it was the half bag plus one of Evans Tyvek SB covers and my LW Mont-Bell parka. I wanted to see if I could survive an Alpine night with just the half bag and the clothes I was wearing, it was a cool night but no frost and the BOM said [approximately] 7C
My top half was just warm enough but my legs were cold
I was wearing 4 layers on top and 2 on my legs
But one of those leg layers were the OR insulated pants; I just get very cold legs easily, my femoral arteries run very close to the skin surface
I think if I had added the Thinsulate bag over the top I'd have been warm enough but that does weigh a kilo and I was trying it out to see if I could lose a kilo from my day trip load
Thanx for keeping those note Mike. I'll order a couple of meters of LW Argon 67 then and Simons last meter of 2.5 Apex and maybe add a second layer at the knees on top and I'll make the outer just a touch bigger

[undercling-mike]

Still, it was good to test before needing to use in an emergency situation, where you'd be cold and tired as well.

An extra layer of 2.5 apex and argon 67 should be a little under 200g and give a nice warmth boost. I wonder if you can make it removable to preserve the function of the half bag as a warmth booster inside another sleeping bag. Another option would be to make a simple synthetic sleeping bag to replace your thinsulate bag, probably looking at around 400g with 2.5 apex and argon 67 and maybe even a short zip but no hood.

Anyway, I've sent a PM with the fabric dimensions used to make your half bag.

[Moondog55]

Mike I think that even with the extra layer it is so slim by design that it will fit inside almost any bag on the market.
One way it will add warmth is that the effect of the sewn though baffles will be lessened and 10C added warmth for 200+/- grams is good value
Of course baffles and another 100 grams of down would be much warmer but I have always liked hybrid bags; my experience tells me they handle the "No bivvy bag" situation a little better

[undercling-mike]

Yep, it should still work nicely. Another option that just came to mind would be extending the synthetic layer above the top of the existing bag to make a kind of hybrid FF vireo. Probably need another ~40cm to go above the shoulders.

[Moondog55]

That is a VERY good idea and would add bugger all extra weight and if I have sufficient fabric and insulation I'll do just that and make it as wide as I can to go over a DAS parka
That would still work as a liner bag too