The wilderness survival community has, of late, taken a keen interest in using reflector blankets or reflector tarps to help create warmer lean-too shelters. The idea is that if the inside of your lean-too has a reflective surface, it will reflect the heat of a campfire onto you as you lie in the shelter.
This is not really a new idea. I can recall Mors Kochanski advocating for this quite a few years ago when he developed his concept of the “super shelter.” Mors suggested placing a shiny Mylar survival blanket on the inside of your tarp to reflect radiant heat into the shelter. More recently I have seen several companies selling survival blankets/tarps. These survival tarps are made of more durable material than Mylar and they have a reflective surface on one side and grommets to aid in set-up of a shelter. One problem with these commercial tarps is that the ones I have found are fairly small. What I am going to show you here is how to make any size vinyl tarp into a reflective tarp that is pretty durable and quite a bit cheaper than a commercially made model. Let me emphasize that I have only done this with vinyl tarps. I don’t know how it would work with nylon or other fabrics.
The idea for this tarp came to me in a blinding flash of the obvious when I was working on one of the out-buildings on my farm. The building in question is about 25 years old and is covered in corrugated sheet metal. The metal was starting to look a little on the rusted side, so I decided that I would paint it with some Rust Stop metallic aluminum paint from our local Ace Hardware store. I bought a gallon of the stuff for about $30 US.
They also had quarts for about $10, but I knew that a quart wouldn’t be enough. So, anyway, here I am standing up on a ladder painting this building when the sun comes up over the trees. In about ten minutes I started feeling like a rotisserie chicken. Man, I thought, this stuff really reflects some heat, and that’s when it hit me. I wonder if I could paint this stuff onto a vinyl tarp? Well, sure enough, I had about a half-gallon of paint left when I finished painting the building, so I decided to try a little experiment on a tarp. I got an old tarp and painted a couple of square feet with the aluminum paint. It flowed on smoothly and covered with one coat. It also didn’t appear to be damaging the vinyl in any way. So far; so good. I let it dry in the sun for a couple of hours before I gave it the durability test. When it was dry I scraped it with my finger nails and there was no peeling. I folded it into a crease, wadded it up, and just generally tried to make the paint crack or peal. The tarp seemed to be completely flexible, and the paint adhered beautifully. I thought to myself, “We may have a winner.”
I unstrapped the 8’ x 10’ camo vinyl tarps that my wife and I have attached to our bug-out bags and went to work. I laid a tarp out on the ground and used a three inch foam brush to apply the paint.
It went on easily and took about 45 minutes to apply. I left the tarp out in the sun for a couple of hours to dry.
When it was nice and dry I gave it another round of durability testing, and it seemed to work great. Even better, painting the two 8’ x 10’ tarps barely made a dent in my half gallon of paint. I bet a quart would paint three or four of these tarps, so if you have friends that are into this kind of thing you could share the cost of the paint.
I did learn a couple of lessons from the first tarp that helped make the second one a little easier. First of all, do this in the shade or on a cloudy day. These things really, really reflect a lot of light and heat. Second, use some tent stakes to stake down the corners before you paint. This keeps the tarp from moving around as you paint it.
So there you go. An easy way to turn a $15 Walmart or Harbor Freight tarp into a high dollar reflective survival tarp.