Sleeping bag layering

[Neo]

G'day
I will be in Kosciuszko area for three weeks this winter, snow camping. July to August.
Not confident that I can sleep comfortably with a combination of my existing gear so looking for advice please.

Tent for alpine is a Bibler, BD Eldorado.

Mat is an STS xs insulated.
Add CCF 3mm of 2m length, or a use a shorter CCF 10mm and something underfoot.

My warmest bag is an STS Ascent 2, comfort -4°C

Existing gear options to add to sleeping bag is any or all of:
OMM synthetic halfbag
Klymit versa blanket, synthetic
Roman 5°C synthetic bag (mid/limit temp)
SOL lite emergency bivvy

Can I make a warm enough combo from this gear, or do I need to buy/loan a better sleeping bag...

[edit, name correction to Ascent]

[keithy]

Enlightened equipment had a good guide for layering quilts.

https://support.enlightenedequipment.co ... ro-camping

I've done similar layering with my 10°C down summer quilt and my 0°C down quilt to around -10°C.

[Neo]

Of course comfort and layering is subjective.

I guess my uncertainty is if double-bagging by putting the Roman bag with an assumed 'limit' rating of 5°C over the STS bag with official comfort rating of -4°C would boost the combo to a comfort
-10°C?

If it did but temps happened to drop lower I'd just suffer a little that night.

Or if the emergency bivvy would have any effect as a VBL or over-bag.

For me the comfort -4 rating has been accurate wearing thermals socks beanie with ground insulation, without added extremes of wind/rain/snow.

[CBee]

For me the comfort -4 has been accurate wearing thermals socks beanie with ground insulation.

Same for me. Toasty warm in the snow.

[Neo]

Loungeroom test.
The Roman (a palm 4) is shorter than the Ascent 2 long. Tried the Roman on the outside and it is a pinch tight too, probably limits the down loft of the Ascent bag.

However, tried the synthetic Roman as the inner bag and I might be on a winner with that combo!

[Neo]

No not happy with layering what I have, compromise the loft of the Ascent 2 from either inside or over-bagging. Even rediscovered a synthetic sleeping bag I had in the late 80s. Not quite right.

Have instead bought an STS Glow 1 synthetic quilt in long, made to suit my down bag. It should fit over nicely and even clip on. $191 and 750g.

Hopefully enough and may even solve that body moisture/dew-point/freeze situation nicely! Can head up the escarpment for some sub zero testing closer to snow trip time

[Lamont]

Well done. Was following whilst you found warmthness. Just curious Neo do you have the Al 1 or 11? Your specs -'Comfort' match the Al1. Just had a squiz, as I know someone looking for a bag, at the specs. Or do you actually have the Al1 model?
Do you have this one https://seatosummit.com/product/altitud ... ii-womens/ 'comfort' suggests minus 10-but you find it OK to no more than minus 4?

[Neo]

Hi Lamont
Here is a photo of the storage bag, same specifications are printed along the side zip baffle of the sleeping bag too.

From memory in 2019 I sold a Micro III which was comfort +4°C and put that money towards this green Ascent II at comfort -4°C that same winter week.

Then in 2020 we weren't allowed out for winter.Barely used as I go with the other gear in combination with a UL puffy and layers most of the year.

So mine is a green Ascent 2, not the womens version and probably a 2019/2020 release model.

I think it is great. They have a stiffened fabric treatment along the zippers which helps prevent snagging, nice added draft/draught baffles, the extra part-length zip on the opposite side can be handy, I like having a foot zip and can also open the whole thing out and use it similar a quilt.

[Lamont]

Ah ha! You egg it said 'Altitude' in the original post. That's what had me confused.
Looks good. May your feet be always toasty.

[Neo]

Struth, sorry about that! I am always saying the wrong word. Maybe I should dox all other references, but I kinda answered my own post.
[edit, fixed OP]

[Moondog55]

Like my own UL synthetic overquilt I expect it would give you an extra 8 to 10 degrees of lower limit and at the same time help with keeping the down bag dryer.
The key will be keeping it in place, the straps are important