Make:

Very good use of reclaimed materials, to be sure! I hope you get some tasty dried apples out of it! Jerky, too. Man, I shouldn't be writing this before dinner. I'm getting hungry.

This is one of those technologies that is constantly reinvented, both because of material availability and just because when a thousand people try to build the same thing, you end up getting a thousand and one different designs. Believe it or not, several people have actually ran controlled experiments on solar food driers, such as this, and found what might be the best design. It's generally called the Appalachian Solar Food Dehydrator, and generally credited to Dr. Dennis Scanlin. He did the main work years ago and I heard him say once that it's the thing he's done that he still hears the most about, from all around the world.

There are pictures here if you scroll down a bit:

http://www.builditsolar.com/Projects/Cooking/cooking.htm

Or right here:

http://www.builditsolar.com/Projects/Cooking/HP57FoodDryer.jpg

The general idea being that the solar collector area is not the same area as where the food is. The long exposed part has some sort of collecting object in it (slanted, black steel mesh, for instance). At the bottom of that section is a screened mesh air vent. At the top, the vertical box part, is where you have mesh trays to hold your food, and all the way at the top are sliding vent doors to control air flow. It usually has wheels and handles to move it to face the sun. This design creates an air flow through and past the food, ensuring that only dry air interacts with the food and whisking away the moisture from the food itself. At night it's important to close the doors so the food doesn't rehydrate, which can be a problem.

The other nice thing about this design is that it can be built from a single sheet of plywood. There's a smaller version you can build from a half sheet. I'm not sure if Dr. Scanlin or Home Power "owns" that design, but I'll look into getting it out in the wild.

Again, great project, and good luck with the food!

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