Quilt + Sleeping Bag

[chall]

Going on a trip this weekend, and it's going to be cold. What would you estimate the new temperature rating would be by using a 45* Mountain Hardware Ultralamina Synthetic bag underneath a 20* EE Revelation down quilt.

[Walkintom]

Just a guess here, but I wouldn't trust it to take me below 10 degrees without the ability to test that combo out in a situation where bailing out was easy.

Cold weather camping ain't no joke. Make sure you at least have an emergency blanket just in case.

[brancher]

Bingo. Also, proper layering is next to godliness. That EE revelation is fine for lower temps, but you didn't mention how cold it would be up there. I use a JRB quilt but also use elastic to make sure it's wrapped and secured around my pad(s) to ensure no cold air intrusion. Hope this helps.

[OwenM]

Did you try it? My conservatively rated at 30F Katabatic Palisade and 50F Underground Flight Jacket were cozy when paired at 4F, and I was using my down jacket as a pillow, not wearing it. Everyone is different, but I sleep very warm, and the Katabatic has an effective system for attaching to a pad to eliminate drafts, plus my pad is a r5.9 Downmat UL 7(supposedly good to -11F). Not something I could recommend to someone else, but I would doubtless be fine to at least -10F with that system. I'd likely wearing the down hoody, though!

[chall]

Did you try it? My conservatively rated at 30F Katabatic Palisade and 50F Underground Flight Jacket were cozy when paired at 4F, and I was using my down jacket as a pillow, not wearing it. Everyone is different, but I sleep very warm, and the Katabatic has an effective system for attaching to a pad to eliminate drafts, plus my pad is a r5.9 Downmat UL 7(supposedly good to -11F). Not something I could recommend to someone else, but I would doubtless be fine to at least -10F with that system. I'd likely wearing the down hoody, though!

When I made this post, it was when I thought I'd be spending last Friday night in very cold temperatures. We ended up cutting the trip short and just did Saturday to Sunday. Snowed all day, and the temps actually rose during the day. Nighttime low was probably high 20's. I was toasty in just the EE 20* Revelation. Here's what the Pinnacle in Hamburg, PA is looking like:
pinnacle.jpg

[Wolf - 23000]

chall,

Simple put, you will freeze your butt off. Your sleeping bag works by trapping your own body heat while keeping the outside elements out. There are other factors but simple put the higher the fill is, the warmer your rating. Your quilt is only going to fill in the extra room inside your sleeping bag. It is going to help some but not a lot. You are better off trying to rent a sleeping bag from REI (I think they still rent sleeping bags).

V/R

Wolf

[OwenM]

Your quilt is only going to fill in the extra room inside your sleeping bag. It is going to help some but not a lot.

The loft is additive. Probably better over the bag like he was asking about, but it would work either way as long as the bag has room for the quilt to loft. No different from wearing a puffy to push the lower limit of your bag, and I've taken the same 30F rated quilt to -2F like that with a down hoody and grid fleece pants over baselayers.

[Cadenza]

I realize your trip is already past, but just to add......

I think the synergistic pairing of down bag in combination with top quilt is an excellent way to go.
My absolute favorite cold weather rig is my Feathered Friends "Winter Wren" rated at 25* in combo with HG 20* Burrow top quilt.
It is a very versatile combination that has kept me toasty down to near zero.

The Winter Wren alone rated at 25* is by itself marginal when temps get down below 32* but the top quilt adds significant loft and really pushes the limits into single digits.
One thing I like about the Winter Wren is that it has zippered arm holes and a draw cord cinched foot box. When nature calls in the middle of the night I don't even have to get out of the sleeping bag. Release the draw string at the foot, and wear the bag like a gown as I walk around in camp. Hike it up to my waist to pee. Back to bed, cinch foot box closed, pull top quilt back over me, and back to snooze zone.
Yes, some of the warm air captured by the bag is lost, but not all of it. The warmth around the legs is of course dissipated when you pull the bag up to your waist, but the torso is still encapsulated by downy goodness as if wearing a parka. Your whole body will quickly warm back up after you settle back to bed.

Another advantage is in packing. The modestly rated bag and the top quilt can be packed in the same compression stuff sack. Together they create less bulk and volume than many colder rated sleeping bags.
I can barely stuff my Western Mountaineering -40 Bison into the sleeping bag compartment of a Mystery Ranch NICE 6500 pack. The Winter Wren/top quilt combo takes up much less volume and can be carried in a considerably smaller/lighter pack.