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Discussion about making bushwalking-related equipment.
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Synthetic overbag DIY number 3

Sat 30 Dec, 2017 8:38 pm

As good as my Nunatak overquilt is; it isn't warm enough.
I'm going to tackle another idea but I need some design help as I'm not sure how to handle the head area of a Gerry Cunningham "Mountain Sleeper"
The Mountain Sleeper is basically a top quilt with a full length pad sleeve sewn to it
RSbtR had some offcuts of APEX insulation very affordably priced so I will be layering 3.6# and 2.5# [ because that was what was cheap, 2 metres of 3.6# and 3.5 metres of 2.5# ] plus a small scrap of something thicker for the footbox
I have no real problem with the sleeve or the basics of the quilt itself.
I'm wondering how I will tackle the hood area tho
I'm also wondering whether I should use a single zipper on the easy side [the Left so I can use my right hand] or if I should use 2 zippers, one on either side and what fabrics to use on the bottom of the shell.
I have also asked this same question over at BPL because some of the members there are more familiar with deep cold conditions.
A layer of 3.6 plus a double layer of 2.5 over the torso should be good for a 20C boost in temperature rating

Re: Synthetic overbag DIY number 3

Mon 01 Jan, 2018 5:13 am

There is every possibility that I'm going to get Evan at TerraRosa to sew this up when i get the design done. It would be cheaper than buying a new sewing machine

Re: Synthetic overbag DIY number 3

Thu 25 Jan, 2018 9:54 am

Well my order from RSBTR has just arrived and the off-cuts were/are a little bigger than described and conversation with the company says that I will not need to have any more than the two layers separated by the scrim.
So I am going to be offering the scrap to somebody who can utilise it

Re: Synthetic overbag DIY number 3

Wed 29 May, 2019 8:59 pm

How did you get on with your overbag plans MD?

I have been contemplating that thinsulate I have. A few plans for mother in law on the go. I keep wondering whether the thinsulate would compress the down of my bag if used as a closed footbox quilt style overbag type set up, or whether it would be better to incorporate the thinsulate as the top layer on a stretchy bag liner inside the bag.

Re: Synthetic overbag DIY number 3

Thu 30 May, 2019 8:21 am

This overbag got cancelled when I bought that huge -50C winter bag. That and the fact that my sewing machine won't sew thin stuff.
It was going to be a project to stretch my current winter bag down to -40C
My thought is that if it is big enough a closed footbox will have very little impact on down loft, it just needs to be about 50mm bigger all around that the exterior dimension of the sleeping bag
The Thinsulate I sent you is probably better for clothing tho, it is a clothing specific item; although the one I made previously does work it doesn't compress for packing

Re: Synthetic overbag DIY number 3

Thu 30 May, 2019 12:23 pm

Ah that's right, I forgot you got the super dooper winter bag that would keep you warm right through the ice age should it come again.

Hmm back to the drawing board on the overbag or liner booster ideas. I do have an aldi ultralight bag here that could be a donor.

Re: Synthetic overbag DIY number 3

Thu 30 May, 2019 12:27 pm

I'd be happy to sell you the APEX I didn't use and the UL nylon fabric too. It is sitting here doing nothing. I have found that the secret to an overquilt is a pad sleeve to hold the mattress in place. Roger Caffins idea. That way the pad gives all the insulation needed on the bottom and if you make the foot box oversized it becomes a warm and dry place to put your boots so they don't freeze over night.
I don't need 2 overquilts and the Nunatak one suffices for my needs now

Re: Synthetic overbag DIY number 3

Sun 21 Jul, 2019 10:53 am

I just ordered a really cheap extra large synthetic bag
It should arrive soon and I'll give a heads-up on whether or not it is worth spending $50- ... .aspx/red/
Even as a donor it might work out as value for money. The biggest problem I foresee is that the zipper is in the wrong place.

Re: Synthetic overbag DIY number 3

Tue 31 Dec, 2019 10:05 am

I thought I should give an update on that LW overbag. While I haven't used it in anger I do think it was worth what I paid for it. This even tho the description was wrong and it has no windproof coating. The members of the Canadian Winter Trekking site have bought a lot of them tho and give good reports on its use as an overbag for deep winter camping

Re: Synthetic overbag DIY number 3

Wed 19 Aug, 2020 10:39 pm

I might have to review my sleeping systems after all. having sold my humungous Arctic bag, I think I need to revisit the idea of another LW overbag that can be used as a warm weather sleeping bag or quilt.

Re: Synthetic overbag DIY number 3

Thu 20 Aug, 2020 3:24 pm

OK I have decided to sew up a new summer quilt, I don't have enough 100GSM APEX tho.
I do however have the 40GSM LiteLoft and 3 yards of 2.5ounce APEX. The combination should be similar to the warmth of the heavier insulation.
I'll use the UL grey nylon I bought from Tier Gear to get the weight as low as I can although I know I'll pay a weight penalty for cutting it overbag size

Re: Synthetic overbag DIY number 3

Fri 02 Jul, 2021 4:33 pm

I pulled this from the unfinished projects box and just resewed it as a regular length bag.
It's heavy at 2150grams but it's synthetic and heavy duty so that is to be expected.
1750mm long not counting the hood, 1935 counting the hood, 950mm wide
Top is cut wider than the base by 200mm
Two layers of insulation on the base, one of generic polyester and one of Thinsulate; three layers on top, again one of generic poly and two layers of Thinsulate
About 30mm thick on top; guessing it adds 12 to 15C to a bags lower limit. Intended as a gift for my mate in North America but willing to sell it locally too.
Good for car camping or when using a sled to haul winter gear
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Hood detail Preshaped plus elastic drawcord
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close up of hood detail
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Big foot, oversized to fit boots etc
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