[Image: 04.jpg -- Photo description: A man is holding the sheet of cardboard, with the long edge against his stomach, the other long edge with the circle cut out on the opposite side. He is using the edge of his hand for a hard edge to bend and crease the cardboard. He is creasing the cardboard to form triangular sections; the points of each triangular section are missing -- the points of all the triangles would have come together in the circular cut out area of the other long side,across from the man. Side A is the side to the left of, and directly adjacent to the half-circle. Side B is the other half of the edge, to the right of the half-circle.]
[Image: 05.jpg -- Photo description: This is looking strait down into the mouth of a cardboard funnel. A man grabbed what was the long edge of the sheet of cardboard, now divided in two by the half circle cut from it. The two now separate edges are now brought together to form a cone. The cone has no tip because of the cut-out half-circle.]
3. Glue Foil to Cardboard. Apply glue or adhesive to the top (inner) surface of the cardboard, then quickly apply the aluminum foil on top of the glue, to affix the foil to the cardboard. Make sure the shiniest side of the foil is on top, since this becomes your reflective surface in the Funnel. I like to put just enough glue for one width of foil, so that the glue stays moist while the foil is applied. I also overlap strips of foil by about 1" (or 2 cm). Try to smooth out the aluminum foil as much as you reasonably can, but small wrinkles won't make much difference. (If even cardboard is not available, one can simply dig a funnel-shaped hole in the ground and line it with a reflector, to make a fixed solar cooker for use at mid-day.)
[Image: 06.jpg-- Photo description: two men are spreading a sheet of aluminum foil across a rectangular sheet of cardboard.]
4. Join side A to side B to keep the funnel together. The easiest way to do this is to punch three holes in the cardboard that line up on side A and side B (see figure). Then put a metal brad through each hole and fasten by pulling apart the metal tines. Or you can use a nut-and-bolt to secure the two sides (A & B) together.
Be creative here with what you have available. For example, by putting two holes about a thumb-width apart, you can put a string, twine, small rope, wire or twist-tie in one hole and out the other, and tie together.
When A and B are connected together, you will have a "funnel with two wings". The wings could be cut off, but these help to gather more sunlight, so I leave them on.
