Materials (for two dehydrators):
3 1x6 3/4" 6-foot cedar boards (these are fencing boards in my area - I picked for few knots)
1 sheet of 8-foot galvanized ribbed roofing (is enough for 3 dehydrators)
2 yards of 36" aluminum flashing
2 32" x 32" storm windows (or other similar sized glass)
Matte black spray paint
2 yards of 36" aluminum screen
Galvanized nails (1 1/2")
1" finishing nails for drying screens
Jigsaw with metal-cutting blade
Table saw with rip fence to produce frame elements
Step 1: A Simpler List of Materials
Two years after initially publishing this Instructable, I found myself conducting a Saturday build of three smaller dehydrators with three friends of mine. I found 3 windows of the same size at the local Habitat ReStore and worked everything from there. I also wanted to get the three of them done in less than a day, so I went with materials that simplified things.
For each dehydrator:
1 24" x 27 3/4" storm door window
Dehydrator bottom: Aluminum flashing, white on one side, shiny on the other: 24" x 27 3/4" (no need to trim ribs)
Heat sink: Aluminum flashing, black on one side, white on the other: 22" x 26" (no need to paint)
Nylon screening: 24" x 30" (easier to work with than aluminum screening)
3 1" x 6" x 6' cedar boards: one ripped 3 1/2" wide (for top and bottom), one ripped 4" wide (for the sides), one ripped into 1" wide pieces (for tray frames). Once the pieces are cut for the box, rip the remainders into 1" wide pieces.
scrap 2" x 2" (about 4" - 6" long) for heat sink handle
1 1/4" galvanized spiral nails (for making the dehydrator trays)
8 1 1/2" deck screws (to hold the outside box together)
For this size, the top and bottom were the 27 3/4" sides of the window.
Because the flashing doesn't have ribs, you'll have add "risers" to the long sides of the trays using scraps of the 1" wide pieces. The flashing is much easier to cut than galvanized roofing! We cut the screening oversize for the trays and found the nylon easier to stretch tight than aluminum screening; it was also easier to trim once the top pieces were nailed on.
We completed three dehydrators in 4 hours.