GG Polycro vs. Window Insulation Film

Mine sure doesn't seem like it. And you can see thru the window insulation film.

Here in the UK, i've been using window insulation film. I also have polycro, and it seems to be very similar, if not the same stuff. I bought it from a hardwear store, and it seems to be just as durable as the GG Polycro.
There is a seller on e-bay selling the same stuff here.
http://cgi.ebay.co.uk/B-&-Q-DOUBLE-GLAZING-WINDOW-FILM-BRAND-NEW_W0QQitemZ160298072017QQcmdZViewItemQQimsxZ20081112?IMSfp=TL081112129001r8100
I can't seem to post a quick-link since the forum changed!

Does anyone know the pricipal differences between the two products below? Both are made from Polycryo which shrink slightly in heat, but the Heatsheet comes with a reflective material which claims to reflect 90% of the user's body temperature.

Does anyone know if one is more durable or more suitable to serve as a ground cloth? Would the reflective nature of the Heatsheet provide minimal heat transfer? While discussing this with both vendors, both mentioned that people from Backpackinglight have been inquiring about it too…so I know I'm not reinventing the wheel.

Adventure Medical Kits Heatsheets –
http://www.adventuremedicalkits.com/product.php?product=147&catname=Essentials&prodname=Heatsheets®%20Survival%20Blanket

Gossamer Gear Polycryo –
http://www.gossamergear.com/cgi-bin/gossamergear/polycryo_ground_cloth.html

James, i tried the AMK Heatsheet and twigs poked through it on the first night. It has nothing like the puncture resistance of Polycro.

> Heatsheet comes with a reflective material which claims to reflect 90% of the user's body temperature.

Which is totally meaningless marketing crap.
For a start, you can't 'reflect temperature': it has no meaning.
Secondly, radiative loss at body temperature is trivial compare to conductive and convective heat loss.

If these coated Mylar films were that good we would have adopted them 20 years ago. But everyone who has tried them has discarded them.

Cheers

A ground cloth is NOT an essential piece of gear.

You can function just fine without it, especially if you have a bivy sack.

"A ground cloth is NOT an essential piece of gear.

You can function just fine without it, especially if you have a bivy sack."

Mmmm. Depends, go for a 7 day walk in Scotland without one or the other, and you might change your mind. ;)

"A ground cloth is NOT an essential piece of gear."

If we could ask Grandma Gatewood, she'd likely tell us that most of our gear weren't essential…

.

If you have an expensive tent, with a silnylon floor, and want to preserve its water resistance, you use a ground cloth. I'm talking Evolution2P here, and, at my age, I might not live long enough to replace it.

Ben2,
Granny Gatewood's advice notwithstanding, do you use a groundcloth with your E2P?

Dennis:

I think you meant to say "if you have an expensive tent, with a silnylon floor, that you waited 340 days for and gawd knows how long a replacement will take… then you use a ground cloth". :)

I absolutely use a ground cloth with my beloved tents! :)

Dave:

It's the constant tug between our love for SUL and our love for new gear that explains why no one here is really 'normal'.

Ben2,
It was 373, agonizing days.