The idea and instructions for this Applebox Reflector Oven are courtesy of Emergency Food in a Nutshell, 2nd Edition, Revised. (THANK YOU!!!) This is a great book!Supplies you will need:
1 apple box (20 inches x 13 inches and 12 1/2 inches high)
extra cardboard (to fill any holes)
heavy duty foil
metal repair tape (foil tape)
1 plastic oven bag
double sided tape
box cutter
butter knife
To start you need a 78 -inch piece of heavy duty foil and a 84 inch piece of heavy duty foil and an apple box.
First fill in any holes you may have in the box, including handle holes, with extra cardboard, tape in place.
It's easiest to trace the hole onto the extra cardboard so you get a snug fit.
Cut it out and tape in place. Repeat the same process with the other handle hole and any other holes you may have in the box.
Next up take your 78 inch piece of foil, it will cover the inside and outside ends of the box and the outside only of the bottom. Lay the foil shiny-side down. Position the box lengthwise and bottom down in the center of the foil.
Fold one side of the foil up the end and inside the box. Smooth out foil and ease into corners (be careful not to rip foil, especially in the corners). Put a few pieces of tape down to secure.
Making sure the foil on the end is snug, repeat for the other end of the box. Fold excess foil on the outside edges of the box onto the box sides and secure foil every 4-5 inches with foil tape, both inside and outside the box. (Foil tape is very easy to tear with your fingers and I like to tear strips lengthwise, and do longer skinny strips as opposed to short fat strips, but that's just me.)
If making a window (not required, but very helpful) - on one of the long sides of the box cut a horizontal window (about 7x4 inches), centered and 2 1/2 inches from the closed bottom of the box.
Next take the 84 inch piece of foil, this will cover the inner and outer sides and bottom of the box. Lay the foil shiny-side down and position the box lengthwise and bottom down, centered on the foil.
Begin on the side of the box without the window. Fold the foil over and inside with box again being careful to smooth everything down and not tear holes.
Making sure the foil on the side you just covered in snug, pull the foil around the bottom and up the side (covering the window), down the inside (covering the window) and across the bottom. Overlap and extra foil over the first edge. Secure the foil every 4-5 inches with foil tape.
Now feel carefully for the window, using the box cutter, cut a horizontal slit in the middle of the window hole, stopping 2 inches from each side. At each end, make diagonal cuts to the corners, it should look kind of like the back of an envelope.
You now have double flaps of foil on all sides of the window. Using a butter knife or your fingers if your careful, carefully ease the inside flaps through the window and down between the box and the outside foil. Fold the outside flaps through the window to the inside of the box and secure with tape.
Cut extra bits of foil tape to put in the window corners so that no part of the box is exposed. Cover edges of window with foil tape to reinforce.
Using a plastic oven bag, cut a double layer rectangle 1/2 inch larger than the window on all sides. 
Using double sided tape secure the first layer of the bag and then again use double sided tape and secure the second layer.
Secure outside plastic edges with foil tape.
Now do a once over on your box, double checking that all of the foil is secure and that there is no cardboard showing anywhere (it will burn).Baking with the Oven:
You will need:
4 empty soda cans, filled partially with sand or rocks (so they don't tip over)
10x16 inch cooling rack
Chimney Charcoal starter
Heavy duty foil longer than box
charcoal briquets
long-handled tongs
newspaper
matches
1-inch rock
This is the basic set up for cooking. The gist is that you heat up the briquets (1 briquet = 35 degrees, ex. 350 degrees = 10 briquets) and they lay under the cooling rack and the food and the heat reflects of the foil surfaces and cooks your food. Genius!
Place a piece of foil shiny-side up on level dirt or cement (nothing flammable). Place pop cans on foil and put cooling rack on top of pop cans (pop cans in very corners of cooling rack but not too far so that the box won't fit). Count out and heat the number of charcoals necessary for the temperature needed (if it's very cold or wet one or two extra charcoals may be needed). Place charcoal starter on a piece of foil, place two pieces of wadded-up newspaper in the base of chimney starter and light. Allow to stand 5 min. until top briquets have white spots at least the size of a dime. Using tongs, place briquets on foil, spreading them out evenly between the cans and across the middle. Place cooling rack on top of cans.
To pre-heat oven, place the oven over the coals and empty rack, resting one corner on a 1 inch rock. This allows enough air into the box for the charcoal to stay lit. Let stand for 5 min. Carefully lift oven off coals taking care not to tilt and place it beside the ground foil. (This holds in trapped heat.) Quickly place food, in pan, on rack and replace oven over coals, resting one corner on the rock. (Food cooked on a cookie sheet should be placed in from the corners as food directly over the cans will not cook.)
Charcoal will burn for 35-40 minutes. When longer cooking time is needed, additional hot coals can be added by slightly lifting the box and slipping them in with long tongs. When food is done, remove oven and serve. Safely deal with the charcoal, dust off ground foil and fold loosely, it can be reused.
Hints:
Use light colored baking pans so that baked foods do not get too dark on the bottom.
Face the window toward the sun so you can see in and check on the food.
For baking in freezing temperatures, place a doubled piece of wool blanket or other material that insulates on top of the box to retain heat inside.
Baking once a day at 400 degrees, will use an average of 12-13 charcoals a day.
One lb. charcoal = about 17 briquets (may vary depending on brand). To bake for 1 year store 16 (20 lbs.) bags = 320 lbs. This allows for a few extra briquets for wet or cold weather.
Again credit for the Applebox Reflector Oven goes to Probert, Harkness Emergency Food in a Nutshell, 2nd Edition, Revised.
Again credit for the Applebox Reflector Oven goes to Probert, Harkness Emergency Food in a Nutshell, 2nd Edition, Revised.
