Mylar sheets are a ubiquitous first aid and survival item for those heading into the outdoors. Since I bought these cheap online just over a year ago, I have preferred to carry a mylar bag instead of a sheet because it's easier to exclude the weather. This particular bag fits in a cargo pocket and has an orange exterior colour, which is great because I generally wear camo and muted tones. This destruction test is sponsored by the last will and testament of a rodent family that ate holes in my outdoor gear. I could repair this bag with a square of duct tape, but since I have spares and have never dirt-tested the bag, it's an excellent time for a destruction test.
The front panel has some setup suggestions. I can't decipher these, but how hard is it to use a bag. The size is 213cm x 90 cm (84" x 36") which is generously sized and will fit even me.
The back panel has more useless information. I kept this paper sleeve to help protect the bag because mylar sheets have a reputation for fragility.
The seams are overlapped and taped. The taping and trimming are quite rough near the ends. I didn't expect taped seams - because taped seams are usually only for the more heavy-duty (and expensive) mylar bags and the mylar bags intended for medical use.
The taped seams peel away easily enough once past the rough top ends. The tape is stiff but reseals just fine. In medical bags, resealable tape provides access to a casualty.
The bottom corner of the bag has small holes. While these holes might look shoddy and let in the wind, cold and water, a small amount of ventilation can help with moisture build-up within the bag. The holes allow a ridgeline to pass through to set up a bivvy tent. Overall, the corner holes are positive for ventilation and enclose the bag more than a mylar tube tent.
I guess somebody tried to make a cheap version of a medical bag using thinner mylar and less expensive tape. The result is a product that was probably rejected by medics and sold cheaply to outdoors people. I'm okay with that - provided one is careful with the fragility of the bag.
An improvised "button" tie-out can be made by inserting some material, such as fluff, dust, a bottle cap or coin and then lashing around that material. In this mylar bag, the button tie out would be the only way to tie this bag out into more of a shelter than a bivvy.
Pictured above is the result of simulating a strong gust of wind; the button tie-out completely rips. Yes, mylar survival bags are known to be fragile. Okay, so this is good to know: I am best to use the bag as a bivvy without tie-outs in windy conditions.
Me and my 185cm, 150kg (6 foot, 330lbs) frame easily entered the bag. The length and width made entry and exit very easy. There was plenty of room to move inside, and I completely enclosed myself within. However, because mylar bags hold in the moisture, it's not recommended to breathe into the bag because the breath is moisture-heavy. I was quickly able to gather the bag over my head and around my face. There was ample capacity is fit a sleeping bag or blanket inside with me too. Although there is no drawstring to maintain the gather, it is easy enough to tuck the bag in so it stayed in place. The bag's size also left plenty of room to ventilate from the head end to control heat build-up. Pictured above is the bag after I had taken a one hour nap. It's hard to see, but there is some moisture build-up from my sweat. If I were there for the night, then I'd expect to feel quite damp and perhaps even have some wetness on the bottom of the bag. A good strategy is to remain in the bag until well after dawn so that you can dry out in the morning sun.
Here the tape and mylar tear as I open the bag out, as shown above. The tape leaves two edges reinforced, and some duct tape would repair the other edge if one needed a larger sheet instead of the bag. While not a total failure, opening out into a sheet was not exactly a success. While I would probably not use this bag as a tarp, it would be okay to open out and wrap around two people (not tested).
If I am out with my dog, I should be prepared to keep her warm and dry - especially if she is injured. I could also come across a lost hunting dog that needs assistance. I found the most reliable way to get the dog sheltered, while still allowing the animal to regulate heat was to open out the bag and tie it loosely around the dog's neck as pictured. Then, I ran the rest of the sheet over her back like a cape, tucked it under her back legs and then walked her backwards onto the slack mylar. At that point, I folded the loose edges under the dog, leaving a bit of the side untucked so she can regulate heat. I left the front untucked in the picture above to also aid heat regulation. Labrador's have thick double-coats, so it took a few minutes to build up noticeable warmth inside the bag.
For the size and weight, this bag has earned a place in a cargo pocket and for any loadout where I am not carrying some other kind of sleeping shelter. The orange colour is excellent for attracting attention. The user should remain cautious with mylar's fragility and be aware of moisture build-up. I am confident this bag could keep me alive in my local conditions until help arrives.
Until next time.
