Do you guys think I'll be warm enough?

[Fish]

I've been out only a couple of times in those temperatures, but it's been the last couple of weekends, and my gear is similar. I agree with the previous poster that you might be better off layering your top insulation, rather than putting one inside the other where compression will compromise the effectiveness.

I think you might be ok. I almost survived low single digits in my back yard with a 20F underquilt, a pad, and a 20F bag + a 40F bag on top as a quilt. I was also wearing a balaclava, and a thick wool watch cap over it, plus warm gloves and lots of wool layers. Didn't have a hot water bottle or hand warmers, though I wish I did. I ended up bailing due to cold feet.

One thing to watch out for is that your CCF pad doesn't compromise the ability of your underquilt to conform to your hammock, creating even small air gaps. You might be better off putting your wool blanket between your hammock layers.

I do have an old DIY UQ that I made out of a youth sized sleeping bag, I might be better off layering the two UQ's and not worrying about the pad at all, actually.

[BillyBob58]

You should be OK to minus 35F on top and maybe minus 10-20F on the bottom.

Does that sound preposterous? Well, it may be a little exaggerated for real life, but it is what everything should add up to theoretically. IOW, if you had a minus 30F TQ, it would have roughly double the loft of your +20F TQ. If you look at temp rating charts like this one from Western Mountaineering:
http://www.westernmountaineering.com...2&ContentId=27

you can readily see that a 20F Ultralite has 5" of total loft(top and bottom layers added, probably about 2.5" top layer loft) and a minus 25F Puma has almost double the loft at 9" and a minus 40F Bison has fully double at 10" loft(caution: these bags are not all in the same series so there might be some other factors relating to temp rating, so not exact).

Your 20F TQ has X loft(probably about 2.5") and gives you roughly 55F worth of protection(75F-20F= 55F). If you use two 20F TQs you should double that loft and add another 55F of protection to 110 for 75F-110= minus 35F.

That is the theory, and it should get you at least plenty of wiggle room., if everything works perfectly. But consider what SilvrSurfr and others have cautioned about. You have the bulk insulation, and if all synchronizes perfectly you should be golden, a toast warm golden like my toast. Sadly, none of this is actually designed to work together and there is much that can go wrong.

Just a few of many things:
1: do you actually know that your TQ and sleeping bag actually keep YOU warm at 20F, or is it only 30 or 35F? 10 or 15F difference there for each could knock you back up 30F, to about zero.
2: You don't know that combining these 2 will actually work perfectly to achieve the insulation that all that insulation would have if used in one quilt made by one manufacturer. For example, fit may be off and down may be compressed, ot there may be some drafts, or both. Or one may slip off the other when you move in the night. etc.
3: Your pad has been used by some down to 30F and some have been OK, so that should buy you another 35-45F( 75F-30F=45F additional protection).
So, 20F UQ - 45F= minus 25F(or maybe minus 10F if you say it's the warm by itself at 40F instead of 30). But as already mentioned, it might interfere with the fit of you UQ. Plus, you don't know at what temp that pad or UQ will actually keep you warm at by themselves. (unless you do know?)

So be careful, you have tons of insulation but it might not all work together as planned. Still, it is all theoretically way warmer than you might need, and you should be able to get extra warmth from layers, especially poorly compressing layers like fleece, so ypu should be OK. As long as you have common sens and don't fight the cold and become hypothermic and stupid from that, well, like you said: if cold at all for more than a little while, just go in the house! So go for it, keeping very close to your bail out. Experience is the great teacher! (don't forget lots of good insulation for your face and head!) And watch that exposed skin which gets frostbite quickly!

[dudeman_atl]

+1 on layering the top insulation.

Also use one layer of clothes that will block moisture like a track suit, etc.

[DanglingModifier]

My guess is that if you get cold with that setup, it will be on the bottom. Cheap CCF Pad + 20 3/4 Length UQ = Unknown Comfort. Lots of variables at play: Experience with UQ setup, thickness and quality of the pad, deformation from pad, how tall you are, how much you move around. Bottom insulation sounds like the weakest link in the chain. Doing it in the yard is a smart call.

[BillyBob58]

My guess is that if you get cold with that setup, it will be on the bottom. Cheap CCF Pad + 20 3/4 Length UQ = Unknown Comfort. Lots of variables at play: Experience with UQ setup, thickness and quality of the pad, deformation from pad, how tall you are, how much you move around. Bottom insulation sounds like the weakest link in the chain. Doing it in the yard is a smart call.

OOPS. In my reply I missed that the UQ was 3/4. Still, for leg insulation it may be enough, especially if your feet will also be in the foot box of the synthetic bag. I am always amazed at how little short UQ users get by with in the foot pad department. Some don't even use a foot pad at temps that would for sure need something for their back.

But, also, will you be using that pad at full length? Because you are probably going to need it to try and get a 20F UQ to zero.

Dude mentioned VBs. I have found that can easily add 15-20F top or bottom for me. But that is if you understand all about VBs, and if you do it wrong it will have the opposite effect and you will be wet and cold. So you may not have time to experiment with all of that, but keep it in mind for the future.

Now speaking about experimenting for the future, is your 20F synthetic bag wide, long and with a full length 2 way zipper? Then consider a pod approach like Shug does so often. Even if it is, this might be tough with a WBBB, due to difficulty getting the net and right side wall and pocket out of the way. Might work, might not. But if you had a winter only hammock, like a netless WB or narrow Claytor or a Swithchback where it is easy to get the net out of the way and low sides or narrow, this can work amazingly well. You might have to add some minor mods to your sleeping bag, but the idea is to just wrap the bag entirely around the hammock and zip it up to your neck. Then, the lower layer of your bag becomes an draft free UQ, and the top layer a draft free TQ, because you are now zipped up in a sleeping bag, without compressing the lower layer. If you have added a suspension mod, you can tighten it up to get the lower layer of your bag closer o your back, if needed. Or leave a nice little gap below your back, and fill it with your UQ. Fill any top gaps with your TQ. I personally think that would easily take a lot of folks well below zero, even before adding your pad as needed.

Obviously it will require some experimentation and possibly some mods to the bag, but several folks have done it with great success. Shug had taken this approach to about minus 40F I believe. Obviously the roomier your bag is the easier all of this will be. For example, the purchase version of a PeaPod is 6 ft wide in the middle, tapering to 3 ft on each end. A PolarPod is significantly bigger.

Good luck, have fun, be safe!

[oldpappy]

I can't add much to this except point out that the wind/breeze on that night will play a significant factor. You need to keep any air movement from robing your heat - don't forget the face/nose. At those temps you need something covering your face and collecting your breath - Shug (the undisputed master) and his videos show what to do.

When using the hot water bottle and hand warmers - put the hot water bottle inside 2 wool socks to start with, then remove a sock as it cools down - save the hand warmers for the wee hours of the morning.
If you don't insulate the hot water bottle well, it will over heat you in the beginning of the night then be too cool to help when you really need it.

[dkurfiss]

I have layered wool blanket with a down top quilt and you will want the wool next to you because it won't compress, then add the sleeping bag, then your quilt over that.

The CCF pad with the 20 UQ should work well assuming you are not a cold sleeper. You will also want to wear a hat, gloves, and very loose fitting socks along with a couple of hot water bottles stuffed into wool sock or some Hot Hands packets. Personally I would also wear a set of light wool long johns but I am a fairly cold sleeper. For sure avoid all cotton clothing because you will sweat while you sleep and it will hold the moisture up next to you and make you really cold.

[mrh_on]

If I'd been home instead of hurtling down waterslides, I'd have come over and pelted you with snowballs while you slept. I hope you didn't get cold and end up running around the yard throwing large boulders over the fence in anger. How did it go?