Mylar Blanket as Underquilt

I had an idea for a 3-season underquilt: A mylar blanket covered in nylon, for durability and protection. The blanket could be suspended fron the hammock much like an underquilt with shock cord. The last time I used a space blanket was on a survival overnight in the pouring rain, and huddled under my shelter, I slowly tore the fragile blanket to pieces throughout the sleepless night, so the fragility of the material might prevent this idea from working at all.

Most space blankets are about 60x80in, but i think the size could be smaller, and the edges of the blanket folded down to create more strength where the nylon would attach to the blanket and where the suspension would be connected.

Has anyone tried this? Would the reflecting properties of the space blanket still work with the nylon covering? Thoughts?

It would then become a vapor barrier,,and if you sweat,,or your body heat condenses,,then no way to get rid of the moisture,,how ever,,some use it.

I use a space blanket to supplement a down under quilt in winter. I use the adventure medical kits one that is more rubbery than the standard mylar and have had much better luck with durability. It could work alone for summer temps though.

rather than go through that hassle - you could just try a reflective ripstop...
DIYGearSupply.com has some - seems to function similarly, though I haven't had a chance to put it into field use yet, just around the house...

Buy a cheap truck windshield reflector.

I use a windshield protector. Works best for me as supplemental insulation, for the windward or exposed side of the hammock(where ever the cold spot shows up).

Seems to condense minimally used that way, as compared to being employed as a vapor layer.

Thank you everyone for your replies! It seems as though condensation would be the biggest issue here, especially since heat would be trapped between my hammock and the sheet. I guess I would have to try it out to see just how bad it would get. I'd also have to see what the temperature limit is with the stuff. I am usually fine in just a 20˚ sleeping bag down to about 40 or 50 with no insulation.

The fabric that WetRiverRat suggested would seem like a good bet, and I'll I'd need would be about 2 yards, so if it doesn't work, no big deal.

Thanks again for the advice!

No, it isn't trapped heat that is the problem, it is rapidly cooling water-vapor saturated air. The metalized mylar may as well be a plastic sheet without metal for the little good the reflective surface will do you.

Several HF members joined on a group buy of fabric-backed reflective blankets, successfully sold to hospitals for short-term and disposable use in cold diagnostic procedure rooms.

Nobody was enthusiastic about the results, try as some did to make it work. Disappointment was best kept hidden with silence.

If you wish to try anyway, punch a neat hole at what will be the low point of the under-hanging sheet, so condensate can drip out.

i use the reuseable tarp/reflective blankets. fold it length wise and put it in between my UL HH and under kit. it worked amazing because its not pressed against your body especialy when you put next days clothes on top of it creates airspace.

now i have a DL blackbird and its a bit different. i need to test out how to layer it properly but im still interested in functioning the same way.

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Originally Posted by WetRivrRat

rather than go through that hassle - you could just try a reflective ripstop...
DIYGearSupply.com has some - seems to function similarly, though I haven't had a chance to put it into field use yet, just around the house...

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@WetRiverRat - Have now, and it worked! Congratulations on a nice DIY project!

HH has a reflective pad that is wider at the shoulders.

I use reflectics, you can get it as wide and as long as you need it.

I had been thinking about using thermowrap. the stuff pot cossies are made from. Its basically bublewrap with outer silver foil on it. that and maybe an old sleeping bag slung underneath.