mycrofft
Still crazy but elsewhere
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Not just for astronauts anymore.
First the cautions; they tear, they conduct elecricity, they melt and burn, they can smother you. OK then!
They come in more than one form. The simplest is just silver Mylar without edging or backing. I have seen them with an insulating backing added and edging applied. Since Mylar strongly resists being pulled apart but can tear like tissue once started, you need to take that into consideration and maybe use tape to form gussets or eyelets. Wildland firefighting "shake and bakes" are super duper versions, but don't steal them. (Mylar will melt then burn if impinged by flame; shake n bakes have a thin reflective mylar layer laminted on, like firefighting bunker suits.
1. Keeping warm/blanket: Wrap it around yourself. Stops wind and reflects heat back to you; also reflects heat away, and can conduct heat by contact. Takes up little room when stowed, hard to re-stow as small.
2. Improving a shelter: if you are in a shelter, either wrap it as above, or line part of the shelter with it to stop air leaks and reflect heat back. Not as easy to do as it sounds.
3. Heat/light reflector: rig to reflect back to you from fire, lantern, sun. Can help make you more visible but, at night, not as good as a white sheet etc. with light shining on it. (Aussies and others did that trick with bed sheets and porch lights or headlamps so Mercury and Gemini astronauts could see their front yards from space).
4. Radar corner: if airborne search and rescue is possible, especially if they are looking for a car or plane, you have two ways to rig two types of radar reflectorts which will give a sharp unambiguous return they will look at.
TYPES OF "CORNERS": the classic is like the corner of a cube. The open end will need to point pretty closely to the direction of search you anticipate. This has the best return and the narrowest angle of reflection.
The "doghouse" or trough type is much simpler. Erect two parallel bars, fix one edge of the blanket on each bar, and place a thin long stripped branch or straightened coat hanger on the blanket to define the reflecting corner (do not fix it in place) then space them apart until the hanging angle is close to 90 degrees. This will reflect best straight up, or back if you manage to fix it in a vertical position. Wider angle of reflection, not quite as strong as the true corner but obviously not natural.
Place a corner on an adjacent hill to draw searchers to your vicintiy or a visual signal pointing to you, or right where you are.
You can do these using any metal, including aluminum foil, but it has to be unwrinkled and flat for the best result. Something you can use that baby warmer foil for besides sharing pizza!
First the cautions; they tear, they conduct elecricity, they melt and burn, they can smother you. OK then!
They come in more than one form. The simplest is just silver Mylar without edging or backing. I have seen them with an insulating backing added and edging applied. Since Mylar strongly resists being pulled apart but can tear like tissue once started, you need to take that into consideration and maybe use tape to form gussets or eyelets. Wildland firefighting "shake and bakes" are super duper versions, but don't steal them. (Mylar will melt then burn if impinged by flame; shake n bakes have a thin reflective mylar layer laminted on, like firefighting bunker suits.
1. Keeping warm/blanket: Wrap it around yourself. Stops wind and reflects heat back to you; also reflects heat away, and can conduct heat by contact. Takes up little room when stowed, hard to re-stow as small.
2. Improving a shelter: if you are in a shelter, either wrap it as above, or line part of the shelter with it to stop air leaks and reflect heat back. Not as easy to do as it sounds.
3. Heat/light reflector: rig to reflect back to you from fire, lantern, sun. Can help make you more visible but, at night, not as good as a white sheet etc. with light shining on it. (Aussies and others did that trick with bed sheets and porch lights or headlamps so Mercury and Gemini astronauts could see their front yards from space).
4. Radar corner: if airborne search and rescue is possible, especially if they are looking for a car or plane, you have two ways to rig two types of radar reflectorts which will give a sharp unambiguous return they will look at.
TYPES OF "CORNERS": the classic is like the corner of a cube. The open end will need to point pretty closely to the direction of search you anticipate. This has the best return and the narrowest angle of reflection.
The "doghouse" or trough type is much simpler. Erect two parallel bars, fix one edge of the blanket on each bar, and place a thin long stripped branch or straightened coat hanger on the blanket to define the reflecting corner (do not fix it in place) then space them apart until the hanging angle is close to 90 degrees. This will reflect best straight up, or back if you manage to fix it in a vertical position. Wider angle of reflection, not quite as strong as the true corner but obviously not natural.
Place a corner on an adjacent hill to draw searchers to your vicintiy or a visual signal pointing to you, or right where you are.
You can do these using any metal, including aluminum foil, but it has to be unwrinkled and flat for the best result. Something you can use that baby warmer foil for besides sharing pizza!
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