Introduction: Reflector Oven for Campfires
The reflector oven, also known as a tin oven was once a popular tool for baking alongside an open fire during the 17th to 19th century. Their popularity has declined since the development of electricity, but these ovens are still used today by outfitters, camps, and outdoor enthusiasts to bake anything from breads, pastries, meats and even pizza. The oven is an enclosed container with one side open to capture the radiant heat provided by an open fire which is then reflected on the top, back and sides of the food for quick and even baking.
This instructable requires minimal tools and experience and can be completed within a day or two. This oven will expand your cuisine options while camping and will be a great conversational piece to have around the fire while enjoying freshly baked recipes in the backcountry.
Step 1: Materials and Tools Needed
For this instructable you will need a large piece of sheet metal, aluminum or stainless steel. Pop rivets, 10.5" x 15" cookie sheet and two handles.
*CAUTION*Be careful not use galvanized metal as the zinc in the galvanizing may create zinc oxide fumes when heated, this can be harmful if inhaled. Most ductwork is galvanized.*
I had found a couple of large almost new pieces of sheet metal that were left over from the construction of a new house. The pieces had been cut and dented a bit but were perfect for my reflector oven. You can get sheet metal, stainless steel or aluminum from a hardware store or local metal supplier.
Tools required: tape measure, square, straight edge, Sharpie marker, tin snips, drill, rivet gun, pliers, hammer, center punch, c clamps, scribing tool (I used an old chisel) and some scrap pieces of wood.
Step 2: Lay Out and Cutting
Layout the pieces on the sheet metal as per the drawings. Layout the large back panel first, this can be split into two pieces if you are using a smaller piece of tin. Then layout the one of the sides and support shelf. Once you cut out the first side and use it to trace out the second side.
The back panel is 17" x 28.25". Cut a 3/4" x 26.5" strip off each side with 1" at each end. Cut 1/4" into the side to make a 1" x 1" tab in each corner so that 1/4" of the edge can be folded over.
To layout the sides, mark in 1" from the edge of the tin and layout the center shape first using the diagram. Once the center is layed out mark tabs that come out 1" from each of the edges, these will be used to fasten the oven together.
Layout the shelf support 2.5" x 34.5" (or longer and cut later as I did).
Using the tin snips cut out the pieces, I suggest wearing gloves to help protect your hands.
Step 3: Shaping the Sides
To shape the tin I used an old chisel to scribe the outside of a bend or fold. This helps keep the bend following a straight line and gives better results. Once a line is scribed, attach some scrap pieces of wood along the line on the good side of the part using some c-clamps. Using a hammer begin to hammer from one side to the other and slowly work along the bend. Don't hammer all the way down in one pass as it may cause the tin to kink, use a few passes. Once you have the tin at a 90˚ bend, remove the clamps and wood and continue to hammer the edge back to complete the 180˚ fold.
Begin with the sides of the oven by folding the top, bottom and back over by 1/4" towards the outside of the oven. Then fold the front edge over in the opposite direction by 1/4" towards the inside of the oven, these folds will hide the rough edges in the seams so that there are no sharp edges. Scribe the front edge at the finished size and fold it towards the inside to hide the rough edge.
Next scribe the top, bottom and back bends at the finished sizes on the outside of the oven. Clamp the scrap wood and hammer the tabs back 90˚. Remove the wood and use the hammer to perfect the bend. Repeat with the opposite side.
Step 4: Shaping the Back
Scribe a line 1/4" from the front and bottom edge on the outside of the oven. Bend this to the inside of the oven by clamping on the scrap wood and hammering the tin. Remove the wood and continue to hammer the tin flat and repeat with the other side. Scribe the sides 1/4" from the edge on the outside of the oven and fold them to the inside.
Scribe a line 3/4" from the front and bottom edge on the outside of the oven. Bend this edge to 90˚ for now, you will adjust this angle later when the oven is assembled.
Scribe the two lines that are 4" apart in the middle of the panel on the outside of the oven. Clamp the wood and use your hands carefully bend to approximately 90˚. Tap lightly with the hammer to help get a defined edge.
Step 5: Shaping the Shelf Support
1) Begin by scribing 1/4" along the long edge of the shelf support, bend this over and hammer it flat. Repeat this with the opposite edge but bend it over to the opposite face.
2) Scribe in 1/2" and fold it over to hide one of the edges and hammer it flat. The remainder piece should be approximately 1.5".
3) On the face with the single fold, scribe a line 3/4" from the edge. Clamp and bend to 90˚.
4) Find the center point of the support, mark 7.5" each way from the center to make 15". Cut through the double fold back to the corner. Bend the support 90˚ at the cut. Measure out 9.75" from the cuts and trim off any excess material.
Step 6: Assembling the Oven
Mark the center points for holes on the side panel. Use the center punch and hammer to set the center points so the drill will not drift off when drilling, then drill all of the holes in the side panel.
Align the shelf support with the side panel, in front of one of the back holes. Clamp them together with some vise grips and drill a hole in the shelf. Set the shelf support aside, align the side panel onto the back panel and drill the two back holes. Use the rivet gun to attach the side panel and the back panel together in the top hole. Align the shelf inside the oven with the lower back holes and rivet the three pieces together. Ensure the shelf is not upside down.
Step 7: Assembly Continued
When aligning the side panel with the edge of the back panel, fold the 1" tab on the back panel 90˚ so it can tuck inside the oven. Line the edge of the back panel with the side, drill the front hole and rivet the two together. Continue with the remaining edges around the side. Once the side is fully attached, align the shelf and clamp it in position with some vise grips. Drill the two holes through the side and rivet the shelf in place. Repeat with the other side.
Step 8: Final Assembly
Hammer the two front edges of the back panel to match the angle of the side panels. Once it matches drill through the side panel and the 1" tab of the back panel and rivet them together. Repeat with the other corners.
Mark out positions for the handles and drill the holes. You can paint you oven with a bbq high heat paint at this time, I had chosen to do a couple of stencils for this instructable.
Once the paint is dry attach the handles and your oven is complete.
Step 9: Using Your New Reflector Oven
To use the reflector oven, insert the 10.5" x 15" cookie sheet on top of the shelf supports. Prepare your favorite recipe, It can be placed directly on the cookie sheet or in another dish which is placed on top of the cookie sheet.
The reflector oven works best with a medium to large pyramid/ platform fire. Get a fire burning hot and set the oven close to the edge of the fire, directly in front of the flames. Prop up the back of the oven with a piece of wood and make any needed adjustments as you go. If you get the oven the perfect distance from the fire you will get even heat on the top, bottom, and back of the food while not burning the front edge. You will need to adjust the oven closer or farther as your fire changes.
Use the handles to move the oven away from the fire to check on your food. You may need to turn the food around to prevent the front edge from burning, a pair of leather gloves are a great asset to have around a campfire for tasks such as this. A good way to check the bread is to poke a stick in the middle and see if any dough sticks. If the stick is clean the bread is ready, if it is gooey then it will need a bit more time. Cooking times will vary due to fire and weather conditions.
Cooking with the oven is a lot of fun and gives you great satisfaction with your finished food.
The oven is also transportable with an additional wooden lid. It will not be 100% waterproof, but it is great to store some small pots and other food prep items that can get wet. It can easily fit in a canoe and can also be tied to an external frame pack through the handles to transport on foot.
Step 10: Hensei
Hensei is a Japanese term used in lean manufacturing that translates to "reflection" in english. A hensei takes place at the end of a day, meeting or event and gives people a chance to express what they enjoyed, what went well and what can be improved for next time.
So far, I had used the oven to bake three different times. First was bread (as seen in the video) second was two batches of cupcakes, and third was another bread. I really enjoyed using the oven and getting outside to cook beside a fire, especially cupcakes with the scouts. It was really exhilarating publishing my instructable (which is my first) and seeing how many people were viewing and favoriting the instructable.
I thought that the oven's performance was really good, it baked the bread and cupcakes thoroughly and even without burning any of the edges.
A few improvements:
-Add two little feet on the bottom front of the oven approximately 1.5” in from the front and side edges. These would help hold the oven onto the edge of a fire pit like in the above photo.
-An edge at the back of the oven that sticks down ¾” to help keep the oven propped on the piece of wood.
-Add holes on each side of the oven so you could spit roast in the oven.
-Have hinges on the joints so the oven can be collapsible for greater ease of transportation.
Thanks for viewing my instructable, I hope it inspires you to get outside and cook on an open fire with some family and friends.