PARABOLIC MIRROR PARABOLOID CONCAVE SOLAR CONCENTRATOR

If you want to make one with a better surface, use silver mirror mylar, house it on a an airtight box with a open hold down ring and draw a slight vaccum on it to vary the focal length. I was doing it with a piece of 1/4 inch tubing from the back with one end in my mouth and starting 2 x 4's on fire from 20 feet away! about 24" or 30"

at 50' it was bright but obviously not as hot

I thought he would have done more than burn sticks............

would make a kick ass snow disk too

lol

i can burn ants with a magnifying glass!!!

It has a focal length of about 30 inches.

why couldnt you heat your house and water with it,

you can,you point it at your water heater and walla scalding hotness.I cook food,like marshmellows and such.You point the parabolical lens at your torso and it keeps u nice and toasty

crap and dangerous. too flexible

Why does he keep burning sticks?