I’ve been trying to explain to people how the folks and KOA managed to cook pretty much everything for the whole weekend inside of a couple cardboard boxes.

Anyway, I’ve tried to explain the things as best as I can, but just to get the whole thing documented, here’s something like the full assembly instructions.

Take a sturdy large box. (A Computer Monitor box seems like a pretty good size.) Completely double-line the inside of the box with aluminum foil (reflective side facing the heat).

The box sits on its side, so that the former top of the box and the flaps are on the side and can be used as oven doors (which obviously need to be closed tightly to keep the heat in – seems like a longish bungee would work for this if you were real paranoid). Put steel rods (such as rebar) or hangers through the middle of the box (to form a rack to place baking trays on). Place an inverted pie tin (with a slightly bent rim to allow air to flow under it) on the new ‘bottom’ of the oven and then another pie tin (right side up) on top; this is where your charcoal goes. (It is important to have the inverted pie tin in order to insulate the bottom of the box from the charcoal.)

Place 2-3 pieces of charcoal in the pan per 100 degrees (Fahrenheit) of cooking temp you need (bigger boxes need a bit more charcoal). The main thing is to make sure that there is absolutely no exposed cardboard inside the box, otherwise your box will ignite.

The kOa variant uses a large ‘outside box’ double-lined with tinfoil on the inside, which then contains a slightly smaller “inner box” that is both double-lined and covered in tinfoil to further reduce the chance of heat escaping. They also hang an oven thermometer inside the oven on one of the pieces of rebar, so you know if you’re getting the temperature right.

(Thanks to Margie for pointing out that such things aren’t that rare and that instructions for various types are out on this ‘internet’ thing.)

Dave notes in an email (since comments don't seem to be working for him):

The lids/doors can actually be left open in varying degrees (so to speak) to control the interior heat. Since you're talking about a pan of burning coals and a lot of reflective surface, keeping the interior warm enough doesn't seem to be the biggest problem ....

The Ks' version of this uses a concrete/fiber/asbestos(?) slab under the pan of coals to insulate the bottom of the box. Pie tins would work on a smaller scale.

It's all amazingly ingenious. Darn clever, these Earthlings ...

Margie (also in an email, for the same dang reason):

The double lining also makes the oven more durable. The one we used have been in use for at least 5 years. Vent tape, designed for high heat, works well for seams and repairs. Heavy-Duty foil is a must. (You can get it in extra wide rolls.)

Asbestos glove, long handled tongs and angled pliers are all useful when handling pans of hot coals.

Archive boxes can also be good, as the lid can give a better seal, and they're a good size for small batches. We use huge tent pegs stuck through the sides of the box to raise the coal tray up, and another set of tent pegs to make a platform for the food.

It's a good technique to use with younger kids, to start teaching them about outdoor cooking, because it's less dynamic than cooking over an open fire.

Ahh, classic guide and scout cooking. Good stuff.

Acutally - you do not want to close the box oven tightly. Fire takes three elements - fuel, ignition, and oxygen - so let a little air in or the fire will smoother.

A simple version:
1. Use any heavy cardboard box (without flaps or fold flaps in) which is large enough to easily cover whatever you're planning to cook.
2. Cover the entire box inside with heavy aluminum foil. (wrap to the outside and secure with duct tape.
3. Cover the ground with foil larger than the box. (or use the grill of your barbeque). Place four smashed soft drink cans (any brand) on the foil and place a metal rack (like a cake cooling rack) on the cans.
4. Place hot briquettes (started in a can or bbq) under the rack - a pie tin makes this easier. 8 should keep the oven at 350 for an hour.
5. Place the food (cake or pie etc.) on the rack and place the foil lined box over the food. Prop up one edge with a small pebble to let in some air.
6. Bake as you would in a regular oven. 350 is 350 whether it is in a box or a kitchen.
Ginger

Acutally - you do not want to close the box oven tightly. Fire takes three elements - fuel, ignition, and oxygen - so let a little air in or the fire will smoother.

A simple version:
1. Use any heavy cardboard box (without flaps or fold flaps in) which is large enough to easily cover whatever you're planning to cook.
2. Cover the entire box inside with heavy aluminum foil. (wrap to the outside and secure with duct tape.
3. Cover the ground with foil larger than the box. (or use the grill of your barbeque). Place four smashed soft drink cans (any brand) on the foil and place a metal rack (like a cake cooling rack) on the cans.
4. Place hot briquettes (started in a can or bbq) under the rack - a pie tin makes this easier. 8 should keep the oven at 350 for an hour.
5. Place the food (cake or pie etc.) on the rack and place the foil lined box over the food. Prop up one edge with a small pebble to let in some air.
6. Bake as you would in a regular oven. 350 is 350 whether it is in a box or a kitchen.
Ginger

sorry for the double postinge - the phone rang
G