Saturday, November 24, 2007

Hobo Stove, Part I

Today's post may be more properly titled, "How Not to Make a Hobo Stove."

If enter the term "hobo stove" into Google, you get about 257,000 hits. Even leaving out the irrelevant results, that leaves a lot of pertinent info available online about them. Before making the stove below, I did look at some of these pages.

Anyway, my goal for this was to see, using nothing more than an empty coffee can and a Swiss Army Knife, if I could make a functional hobo stove for cooking either while camping or in an emergency. An important feature is the ability to use any flammable solid that you can put into the stove as fuel. E.g., twigs, bark, pine cones, cardboard, etc.

First, here are pictures of the front of the stove, with an air intake and fuel feeding window at the bottom (what was the top of the can), and then an exhaust vent/fuel feeding window at the top (formerly the bottom of the can).

As you can see above, I did not cut through the rim of the can. I left the rim on so the stove would be more rigid.

To cut out the windows, I punched out the corners of each window with the reamer on my Victorinox Farmer Swiss Army Knife. Then, I cut between the holes using the knife blade. The knife cut the can OK but was dulled quite a bit by doing so. If you're going to try this, you'll be better off using tin snips or a cutoff wheel in a Dremel. Watch out for sharp edges on the can.

Our next picture is of the tinder pile I made to get it started. I used my Victorinox Pioneer to make a pile of fatwood scrapings and some splinters onto a piece of cardboard, then used the reamer as a striker on the ferrocerium rod.

Once the tinder was going -- which took only a few strikes on the ferro rod -- I added a few twigs, then placed the stove over the burning pile and starting feeding more twigs in through the exhaust vent. The lower vent was facing the prevailing wind, so each time a breeze picked up it fanned the flames.

Note my high-tech pot, a cranberry sauce can left over from Thanksgiving. ;)

Finally, here's a shot of some flames coming out the back exhaust vent.

OK, so why is this, "How Not to Make a Hobo Stove?" Simply put, this layout doesn't allow you to build and keep going a hot enough fire, at least with scrounged fuel. It works only with rather small pieces of wood or pinecones. Despite my best efforts, the water in the cranberry sauce can never boiled. It did warm up and start giving off water vapor but never came to a good boil. A bit of water spilled on the top of the stove did sizzle off, but the two layers of metal between the fire and water kept it from getting hot enough to boil in the can. It might work better with charcoal briquets.

Having tried this setup, I'm going to play with it a bit more. I'll probably try charcoal briquets. Also, I'll flip the coffee can back over and make a pot support for the top using either wire hangers or some hard cloth/chicken wire. I may also make what was the exhaust hole a bit larger so I can feed larger pieces of fuel into it.

Stay tuned for part two.


Timbo said...

Would poking a few holes on the top of the stove allow heat to more effectively warm the can being cooked? I sound like an idiot here, but wouldn't that allow for less heat to be absorbed by the stovetop, and more heat to be transferred to the can?

Dave Markowitz said...

That might work and is worth trying. However, I have the sneaking suspicion that combined with the limited fuel capacity of this can, it won't be enough to make the stove useful.

Wil said...

Your vent is too big. That's where your heat loss is happening.

Anonymous said...

Thanks for the article. neat. I'm going to try this. said...

I've found that if you're going to use wire for a pot supports, standard coat hangers usually don't work --- unless you get the thicker hangers that you get from the dry cleaners. A standard coat hanger is not very sturdy. Metal tent pegs for the best.


Everett De Morier