Overbags or over quilts for sleeping bags

[Watertank]

I have a Western Mountaineering Summerlite - which is rated to 0 degrees and an EE revelation rated to 0 degrees; and a few other bags.... - I am planning to do the Overland in November (yay!) - the recommended rating for a bag then is -10 degrees. I am wondering whether I can double up by taking the Summerlite and the Revelation as a cover bag to boost the temp. Of perhaps another bag. I don’t have a -10 bag. Any thoughts on combinations and how to work out what the rating might be if I combine bags or a quilt and a bag?

[Heremeahappy1]

Nesting or stacking bags/quilts is a tried and tested method.
I have a +4 and -2 quilt that I stack for snow trips, combined weight is still under 1 kg.
See https://support.enlightenedequipment.co ... ro-camping or Shug Emery on Facetube.

[Moondog55]

So long as the overbag/overquilt is large enough it is a very valid concept, used, tried and tested for decades.
If you normally sleep naked at around 24C then a 0C rated bag should add that extra boost to the bag used as an inner, so layering two 0C rated bags should be comfortable to around -20C
A little less than the EE rating but close enough in real life.
My personal preference is for a synthetic outer as those are easier to dry out but either works, as would wearing extra cloths to sleep in but the Summerlite is far too skinny for doing that so the overbag makes sense

[Watertank]

Thanks for those really helpful responses.

[Al M]

Where are you getting the -10 C figure from? Average temperature sea level for Tasi that time is around 8-9 C with maybe 5 C less for every 1000m altitude plus or minus weather extremes so more likely around 0 C

I also have a WM Summerlite 0 C bag and got by in many places colder than that. Unless you are a very cold sleeper but even then you should be fine with additional layers as there are only five nights on the Overland to survive on. A normal liner will add a further 3-4 C warmth.

[Tino B]

Recommendations by Parks Tas is -10c. It allows a safety margin for most. I’ve camped at Leonard’s Tarn when it was cold enough to freeze water bottles solid in late March. I coped in a 4 season tent, a 30F quilt and a Borah Gear bivy bag with light thermals. Huts are probably colder than a good tent.

[Moondog55]

10 degrees is a reasonable safety margin, and while we know that part of it is CYA, unusual weather is normal.
Most reasonably experienced people know what the limits of their gear is but Parks all over need to keep thnking about the beginners and the less experienced

[flingebunt]

When you look at the rating of your bag, is it -5 for comfort or -5 for extreme. I think that the -10 rating would be for the extreme level of the bag in case of those Tasmanian summer snow storms that can happen, rather than the comfort rating of the bag.

A couple of other strategies to boost your bags rating
- If you are not planning to take a tent, you can take an emergency bivy bag as a backup shelter. When you put your sleeping bag inside the bivy while you are in a hut, it will be able to handle much colder temperatures. The emergency ones are fairly small and light, so not a big weight addition to your pack and something good to have in general for emergencies.
- Use a thermal bag liner to boost the warmth of your sleeping bag. These are much smaller and weigh less than an extra bag/quilt and they can be a good investment, with some people using these for camping in summer when a sleeping bag is over kill.
- Remember you can sleep in your clothes. Your bedtime clothes can include thermal underwear and thermal shirt, thick wool socks, gloves and a beanie. These can also be worn under regular clothes on cold days if needed.

[Moondog55]

The main problem with wearing more thaan baselayers in a Summerlite is the size of the bag, to get the weight down it is a very skinny cut. Only a 1500mm girth so if you are any bigger than a medium in the chest there is no room to layer up. The VB liner is however a great idea, adds an extra 5 C at least in my experience but a bad idea over the outside unless it is a very breathable fabric whicmost cheap and LW ones are not.
With the Summerlite being rated to 0C for comfort [ when wearing baslayers etc] and in a cold snap using a VB liner such as a big plastic bag or one of the silver ones plus a black bag over the outside I would be taking jst the sleeping bag and working out an easy way to layer a jacket over the top of the bag, a few strategically place buttons and loops works. What static insulation layers are you taking? Have you tried layering up and seeing how much clothing you can wear?

[Watertank]

The Summerlite has enough room for me to wear a down jacket inside plus thermals etc- I will be taking a tent, either a dan durston or a one person hilleberg, plus a warm sleeping mat. The Summerlite plus my EE quilt is just over 1kg so nothing that I’m concerned about and I’m a hot sleeper.So I either go Summerlite plus clothing or take the Summerlite plus the quilt. The clothing option is more attractive weight wise.

[Mark_O]

Hi Watertank, I use a very similar configuration to what you are describing and that combination will work well although the outer quilt will get quite damp. I have used a WM Summerlite with a quilt for snowcamping/winter trips as one of my winter sleeping options for over ten years. I originally paired it simply with a Mountain Designs synthetic over quilt that was designed to zip onto one of their sleeping bags for additional warmth. I picked up a couple of these for $20 each in their bargain bin many years ago and sewed some straps on so that I could use one as an overquilt for my Summerlite. The over-quilt would be more like a very narrow 5 degree bag/quilt but the combination of the two worked perfectly in the snow. The inner bag almost never gets damp however the outer quilt often does. Although I'd recommend a synthetic over quilt I think your EE will work fine despite getting a little damp. On a really long trip it might eventually become an issue though. These days I have moved to a down quilt and a custom made synthetic over quilt (both by Undercling Mike) that achieves the exact same system but at higher quality and less weight. Throughout this time I have always had a OP Winterlite bag but I really only use it for car camping in super cold weather as it is so much heavier and bulkier than the sleeping bag (or quilt) and over quilt system.

[rangersac]

Just back from a trip up to Ben Lomond where I tried out the overbag technique. Temps were down around -2 to -3 overnight, and probably just above freezing inside the tent. I paired a lightweight duck down bag rather rated for 5C comfort with a 50GSM polyester insulation XL overbag. The system worked beautifully, and space wise was much more compact than my single winter bag which is rated to -8C.

[Watertank]

I also have a https://www.astucas.com/en/products/sestrals-quilt/ rated to 2 degrees so perhaps that is better as the over bag rather than the EE quilt as it is synthetic.

[Heremeahappy1]

@rangersac great to hear your success. Stacking quilts or bags is a low-fi, economical, lighter approach and gets you a greater total temp range. One way to lessen our consumerism.

[Moondog55]

I also have a https://www.astucas.com/en/products/sestrals-quilt/ rated to 2 degrees so perhaps that is better as the over bag rather than the EE quilt as it is synthetic.

If it is rated accurately at 2C it should give you more than enough boost and in my experience synthetic is worth the small weight penalty for use as an overquilt, simply because if they get damp they dry faster in our soggy winters.
If it was the large size it would naturally be better so as not to crowd and compress the footbox of the down bag on the inside but even so it should work fine.

[ChrisJHC]

Another thing to look at is your sleeping mat.

Not much point having all that insulation on top if the heat is all seeping out the bottom.

Remember that the down underneath you gets compressed and provides almost no insulation.

[stu]

Go the double bag.
I really don't think you have to count grams on the OLT, the days are short, there are huts if you need them & it's one of the most trodden & easy tracks in Tas. Go all the luxury items, unless you're back or knees are shot. Better to be too hot than too cold. IMHO, being more pedantic about your pack list comes with the harder walks, WA's, Southern Ranges etc where there are no huts for safety & you're at the mercy of the SW weather. Keep your sleeping thermals & bag dry at all costs & you'll survive most any trip in Tas.

[emma_melbourne]

In addition to the double bag...

If you have a puffie jacket with you and Merinos anyway, in addition, you can always add layers if you get a super cold night and the sleeping bags are not enough.

When I did the Overland Track I had a -6 degree quilt, and I found at 2 degrees I was a bit cold, and wore layers and added my down hoodlum. And as the temperature rose I could shed layers.

But for other nights it was warmer and I stuck my feet out of my quilt.

So adaptability is good. Achieved well with the 2 bags, and the other layers you carry with you anyway.

Have luck!