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How to Make a Collapsible Solar Box Cooker

It is pretty simple to make a collapsible solar box cooker from two cardboard boxes. The trick is to cut off the bottom of each box, creating two pieces: the base; and the sides. After that, it is possible to collapse the box by folding up its sides and laying them into the base; or, when you want to use the cooker, insert the sides right into the base (Figure 1), extend the accordion sides, and fold the flaps down inside (Figure 2).

wpe1.jpg (28581 bytes)The lid fits perfectly onto the base of the larger box, so that, when collapsed, the cooker takes the form of a convenient, briefcase-size box.

The instructions below only show how to make the collapsing box part of the cooker. The top can be built following the instructions for the lid on the Minimum Solar Box Cooker.

Click any of the photos below to see a larger version:

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Figure 1

Cut the bottom off the larger box. Make an accordion fold in each of the shorter sides. Then place the sides down inside the base.

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Figure 2

Make two creases in each flap so that once they are folded down, they form a double wall with about a 1" (2cm - 3cm) airspace. Note that you will have to trim down the shorter flaps on each side so that they can be folded down after the longer sides have already been folded down.

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Figure 3

Place two cardboard hoops into the bottom of the larger box. These will maintain the airspace between the larger box and the smaller box.

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Figure 4

Cut the bottom off the smaller box and place it inside the larger box so that it rests on the cardboard hoops. Place the black metal drip pan into this base.

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Figure 5

Prepare the sides of the smaller box as you did with the sides of the larger box. Then set them down inside the assembly so that they go inside the base of the smaller box.

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Figure 6

Then fold down the sides of the smaller box so that they tuck into the base of the larger box. Trimming off one corner on each flap makes the tucking much easier.

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Figure 7

Now you have a completed base.

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Figure 8

 Instructions for building the lid are the same as for the Minimum Solar Box Cooker. Place the lid on, and you're ready to cook. You can make any size cooker using this method.


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