emergency reflector blanket in underquilt?

[TreeBeard13]

I am gathering the necessary components for a full under-quilt, and a separate down 1/2 or 2/3 down under-quilt add on for colder weather.

Would it be advantagous to sew in one of those silvery "emergency blankets", or would that just cause problems? Anyone ever try it? Tips/tricks/input?

Example:

Top nylon shell
down fill
Sliver emergency blanket
bottom nylon shell

[zooshooter]

It would not be advantageous. The blanket you refer to is made of mylar, which is a plastic sheet with a thin coating of aluminum on both sides. These blankets do not take well to being punctured (by a sewing needle). If you're looking to save money on an underquilt, use synthetic insulation. If you're looking to increase the warmth rating of a down underquilt, use more down. The mylar will also act as a vapor barrier trapping moisture and reducing, if not eliminating, the efficacy of the down you DO have. You could place one of these blankets between the hammock and the UQ as a separate item, but please read up on how to properly use vapor barriers first as they can do much more harm than good.

[MAD777]

You definitely do not want the down between you and the mylar vapor barrier. Moisture from your body will saturate the down.

The following is true for both vapor barriers and for radiant heat reflectors;The closer they are to you, the more effective they are.

But, as cautioned above, vapor barriers are tricky to use and can backfire.

[TreeBeard13]

It sure is nice to have knowledgeable people to draw on. Trail and error sucks.
Thanks!

[BillyBob58]

I don't know about sewing, but simply adding one between my hammock and a number of under insulation types works very well indeed for me. Just keep it warm, don't put it anywhere to the outside where it can get cold because that is asking for condensation and wet insulation. Having it next to my hammock, very close to me, has resulted in (for me) either very little or zero condensation on the surface of the mylar blanket right under the hammock, while assuring that (just like any correctly working vapor barrier) that there is zero condensation or sweat getting into my insulation where it does the most harm. YMMV, but try it, you might like it. It seems to add 15 or more degrees to my HH Super Shelter, and I have used it many a time down on top of the bottom layer of a PeaPod many times also, to boost it's warmth and keep it dry.

Also be aware that, like any VB, it might boost warmth to the point where you are actually too hot- over heating. So to avoid sweating, unless you are near or below the low rating of the UQ, you might sweat. Of course, it is possible to over heat and sweat with no VB. In that case your insulation will soak up your sweat, and you may not even know you were sweating until you down starts loosing loft after a few days on the trail. (I have seen it happen) But at least if you sweat on the mylar, it will not go down into your UQ insulation. But just pay attention to your warmth and be prepared to vent to avoid sweating from over heating.

[psyculman]

There is a product called 'Thermaflect'. It is the 'paper' like blanket used in hospitals ..... a disposable 'blanket', blue on one side, and 'metalic' on the other side. You have probably seen one of them.

It is incorporated into everything I make. (as is Insultex)

I got a few in a group buy here with HF. When I ran out, I contacted the manufacturer at Thermoflect. The representative sent me 6 for free, and asked me to let her know about my use of the Thermoflect, and how I incorporated them into DIY items, which I did. It must have not made much of an impression, even with pictures. The Thermoflect representative , would not acknowledge any further requests for more. I think probably if I had a connection to someone who did purchasing for a hospital I could get more. Which I would.

The Thermoflect is the layer, behind a layer of Insultex, and then down. (of course, inner and outer down proof fabric too) It greatly adds to warmth. That's no hype. It is quiet, and sews well into a UQ, or OQ. It may however not stand up to washing. Haven't had to do that yet. Probably won't ever wash my down stuff. Although there is 'metalic' coated rip-stop available, the Thermoflect is VERY light weight, and is perfect for my use. It is a vapor barrier, and, condensation issues are not caused by it's use. It does reflect body heat.

[leave_the_bronx]

I've thought about using those emergency blankets in my UQ or TQ as well, but have never had the need. Thanks for asking the question and helping answer mine.