Insul-Brite Layering Questions for UQ

[thedavil]

So, I've been brainstorming an underquilt design, and went to get materials yesterday. I got 2.5yds each of: PolarLoft, One-sided PolarFleece, Insul-Brite, and Some windstopper ripstop nylon. In addition, I have some super-thin WPB fabric (probably 2.5 layer) and plenty of heavy tulle.

Now I'm sitting here staring at the pile of fabric wondering how on earth I should sandwich all this stuff together. I read a great article last night that explained all the properties of Insul-Brite and the best configuration to use it. I can't find the article again, but the gist of it eludes to the fact that the insul-brite would perform best at 3/4 of an inch away without any significant amount of fabric between it and the heat source (aka me).

I considered the possibility of just using the Insul-brite, ripstop, and WPB with the 'right' side of the WPB facing the same direction of the 'right' side of the insulbrite and the ripstop on the bottom. The insulbrite would be in between the WPB and ripstop. This way I could have a vapor-barrier and shiny side of the insulbrite working for me in dry, colder temps (High Sierras...my summer/fall home), and flip the setup over in warmer, rainy temps (Hawaiian Tropics...winter stomping grounds).

To keep the 3/4 inch gap between myself and the insul-brite, I considered sandwiching strips of the PolarLoft every so often (maybe in a grid with 6"-12" cells) between the insulbrite and the WPB layer...kind of like a waffle.

Now, what I am wondering is whether the WPB layer is going to cause an issue with the heat retention capabilities of the insul-brite, and if so, would it be better to fore-go the vapor barrier layer and use the heavy duty tulle instead? Having used vapor barriers before in survival situations to keep warm (eg Trash Bags as sleeping bags), I know that they can be very effective at conserving body heat, but I see no point in carrying around the extra weight and bulk of insul-brite if it is not going to have its full effect in this setup.

Any insight would be heavily appreciated.

[JohnSawyer]

I have limited Experience with IB, but have found it seems to work best close to you...

I would go (from your backside, toward ground)
Ripstop, IB, Primaloft, Ripstop. IB isn't strong enough to hold up on it's own...

Then I would take your VB material and make it fit your UQ as an inner liner... That way you could remove it for the tropical trip...

The only downside to IB is it doesn't compress much and in dry climates, every wiggle charges it up like a static generator...

[saniun]

Im thinking about sewing an emergency blanket to a sheet of batting and nylon. The outer shell being the space or emergency blanket. I want the heat to escape from me into the batting and be sealed of by the eb so the nylon side will be next to me. I imagine I could do a full uq this way astill stay very light

[JohnSawyer]

Im thinking about sewing an emergency blanket to a sheet of batting and nylon. The outer shell being the space or emergency blanket. I want the heat to escape from me into the batting and be sealed of by the eb so the nylon side will be next to me. I imagine I could do a full uq this way astill stay very light

The only problem with this is that any moisture will collect in the batting. You're better off putting a vapor barrier next to your skin...

And cheap space blankets don't sew well, they just tear...

[thedavil]

I have limited Experience with IB, but have found it seems to work best close to you...

I would go (from your backside, toward ground)
Ripstop, IB, Primaloft, Ripstop. IB isn't strong enough to hold up on it's own...

Then I would take your VB material and make it fit your UQ as an inner liner... That way you could remove it for the tropical trip...

The only downside to IB is it doesn't compress much and in dry climates, every wiggle charges it up like a static generator...

Thanks John, now as far as the direction for the shiny side of the IB, I have seen mixed opinions, and even on the packaging it says that the IB will reflect cold as well as heat. Do you think it would be as effective as a cold barrier as opposed to a heat trapper?

[FLRider]

Thanks John, now as far as the direction for the shiny side of the IB, I have seen mixed opinions, and even on the packaging it says that the IB will reflect cold as well as heat. Do you think it would be as effective as a cold barrier as opposed to a heat trapper?

It should, but the air temperature outside would have to be warmer than your body temperature (or you'll have to have quite a bit of ice or an A/C unit in your hammock) for it to do any good. All insulators do is prevent the seepage of heat from warmer areas to cooler ones. If you're already warmer than the surrounding air, that means you're going to roast in your own heat (or stay warm, if you're in air that's cool enough).