As part of a physics class energy project I was instructed to make a Hobo stove and measure its efficiency. It has proven itself to be a worthwhile stove cooking marshmallows, hot dogs, hot cocoa, eggs, and even that cardboard called ramen. It's a low budget stove that will benefit anyone that decides to make it.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Gather Materials
- 2 No.10 cans/ One with a lip around the top as seen on coffee cans
- 1 No.2 can
- Stove Cement/ or other adhesive that can withstand high temperatures
- Drill/ or worst case screwdriver
- Wire mesh
- Tin snips
- Copper or other metal pipe 1in. in diameter
- Metal Strapping
- Wire, copper even fishing line will do
- Sheet metal
- Electrical tape
- Can opener
Using the can opener cut the bottom off of one of the No. 10 cans, save the metal disc for a later step. Cut a large semi-circle out of the side of the can, however, do not cut past the halfway points of the can. Next, cut a 4 to 5 inch strip of metal strapping and screw it into either side of the can. Make sure the strapping faces upright after tightening.
Next, using tin snips cut approximately a 2 inch square hole in the second No.10 can. Cut the bottom of this can, leave the top part with the metal lip alone.
Fasten the two cans on top of each other, the can with the large hole in the side goes on the bottom. This will act as a stand and air hole for the stove.
Using the tin snips again, cut out 2 swaths of mesh and place them criss crossed in the top can. The fuel will lay on top of this and the criss cross pattern will prevent small burnables, such as pellets used in testing, from slipping through the mesh.
Taking the No. 2 can cut a hole with the tin snips as close to the pipes diameter as possible. Next, place the pipe through this hole and have it stick out an inch past the bottom, this will be the smoke stack for the stove. Seal the cracks left by the hole in the can with an adhesive or stove cement
Wrap the copper wire around the pipe and secure it on either side of the No. 2 can with screws. Screw in two more screws perpendicular to the previous ones. This will keep the pipe from being jostled and potentially breaking the stove cement, the screws will also hold the stove up off the bottom of the can. Next, take the bottom of the No. 10 can you cut out and cut a circle the diameter of the the No.2 can, again make this cut as close to the can's diameter as possible because the screws in the No.2 can will lay on the disc to hold the stove up.
Next, cut the sheet metal out in a strip that is 5 inches wide and 4 inches longer than the circumference of the No.2 can. Wrap it around the can, having the metal stick out past the lip of the can by 2 inches. Using electrical tape tape it to the No.2 can .This metal wrapping will surround your fuel and ensure that the majority of the smoke goes up the stack.
Place the No.2 can inside the top number one can. The metal ring around No.2 can should sit on the lip of the No.10 can and the screws in the No.2 can should sit on the metal ring.
Step 10: Using Your Stove
To use your stove place your fuel in a ball of newspaper, paper towel, or among other kindling. This is if you want to conserve fuel by making it more efficient, as the ball will be then covered by the metal around the No. 2 can forcing the smoke up the stack and therefore through the No.2 can which holds the water. If conservation is not an interest the metal around the No.2 can can be removed allowing more fuel space. The fuel will receive oxygen from the holes in the mesh and the large hole in the bottom can. Use the stove Responsibly and always watch to avoid starting a forest fire.
In my testing I was concerned more with the efficiency than with food safety. Some of the stove cement comes in contact with the water as it seals the hole between the pipe. This can be a food hazard, so I recommend using this at your own risk.
Step 11: Comments
If you have comments or questions please ask them below I will be happy answer them. Thank you for reading.