Roy Robinson's Cat Stove

The original tuna can stove hiked with me along the Pacific Crest Trail last year (1999) for over 1500 miles, from Donner Pass near Lake Tahoe to Manning Park, British Columbia.  It served me well for almost three months, heating water for soup, cooking dinners and warming the occasional morning cocoa without any problems or failures. This new, lightweight version of my stove was introduced at ADZPCTKOP2, (i.e., the Second Annual Day Zero Pacific Crest Trail Kick Off Party,) at Lake Morena. It wasn't the prettiest or the lightest stove there but it did boil one cup of water the fastest  in 2 minutes, 24 seconds.  Like the original tuna can alcohol stove, it will bring two cups of water to a boil in about 5 minutes, has no moving parts and will fit inside your cook pot.  Unlike the original, the new cat food can stove weighs just 1.6 ounces including the stand and windscreen.  To save space, let's just call it the Cat Stove.

MATERIALS:
The drawing below shows the three parts of the stove.  The Burner is made from a 3 oz. cat food can and the Air Jacket is a 5.5 oz. cat food can. 2 x 3 inch welded wire screen is used to make the Stand.  The aluminum foil windscreen is not shown in the drawing. raw materials needed to make the stove are shown in Photo No. 1.  These are:

§           Fiberglass insulation.

§           2 x 3 inch welded wire for stand. 

§           Heavy aluminum foil for windscreen.

Photo 1.  Required Materials.

MAKING THE BURNER: 

 

Using a small church key-type can opener, cut six tabs from the inside out around the sides of the smaller can.  Cut some fiberglass material and place it around the inside of the can, holding it in place temporarily with a coil of metal window screen.  The fiberglass should come no higher than the bottom of the tab holes (about 1 inch above the bottom of the can), and should be about 0.2 inch thick.  See Photo No. 2.

Photo 2.  Air Jacket  and Burner.

The window screen can be removed after the stove has been used once or twice.  If you prefer, you can burn a couple tablespoons of fuel in the burner now, and then remove the screen.

MAKING THE AIR JACKET:

Cut a 1.75 inch diameter hole in the bottom of the larger can and six tabs from the outside in around the edge.  I cut a hexagonal hole in my stoves for no reason other than it's easy.  You can see this in Photo No. 2.  Use a large church key to cut the tabs if you have one. 

ASSEMBLING THE BURNER AND AIR JACKET: 

 

Straighten the tabs so they point directly toward the center of the can and cut the sharp points off the tabs, no more than 1/16 inch.  This will help the tabs hold the inner can in place more firmly when they are assembled.

Now, aligning the tabs on the two cans so they will miss each other, push the burner into the air jacket.  Adjust the tabs, if necessary, so the burner is centered inside the jacket.  The jacket should be pushed down onto the burner until it and the burner are both resting on the work surface.

 

Photo 3.  Wind Stand (left), with the Burner and Air Jacket in Position for Assembly.

 

Caution:  In bright daylight, you may not be certain the stove is lit even when it's at full heat.  Be careful you don't find out the hard way by getting part of yourself or any burnable material too close to the stove while it is burning.

 

Finally:  This is an ALCOHOL stove.  DON'T USE WHITE GAS, COLEMAN FUEL, OR ANY OTHER GASOLINE FUELS IN THIS STOVE!

 

If you have questions or suggestions for improving the Cat Stove, please write to the address below.  Good luck to you on the trail!

 

Roy L Robinson

539 Los Ninos Way

Los Altos, CA  94022

 

 

OK, you talk, we listen.  My son Brian was over for Father's Day yesterday, and we spent some time working with the Cat Stove.  Here are the results:

 

Cut a 1 x 11 " piece of the aluminum foil which you have already used to make the windscreen, and wrap it around the air jacket of your Cat Stove, covering the air intake holes.  Tape the ends together so it forms a simmer ring that will slide up and down, covering or exposing the air holes (or anything in between).  I used metal tape, but a staple (punched from the inside out to avoid hang-ups) will also do the job.  You want to cut the simmer ring down to where it will just cover the air holes.  That way, it won't obstruct the air flow when you raise it to let the stove roar.  Mine ended up at 7/8 inch in width.

 

With the air holes closed and 2 tablespoons of fuel, the stove kept a pot of water simmering for 25 (!) minutes before burning out.  It acted like a Sterno can, burning the fuel very slowly because it was starved for air.  Next, we slid the simmer ring up so the air holes were completely open.  Again, 2 tbsp of fuel and a pint of cold tap water in the pot.  The water came to a full, rolling boil in under 4 minutes (ideal conditions, 70 degree evening, no wind).  I then too, the pot off, slid the simmer ring down to cover the air holes and returned the pot to the heat.  It simmered for another full six minutes (10 minutes total) on the original 2 tbsp of fuel!  BTW, is anyone still unconvinced about the merits of an air jacket to improve the efficiency of an alcohol stove?

 

With the addition of the simmer ring, your cat stove can be set to burn 2 tbsp of fuel in anywhere from 6 minutes (full power) to 25 minutes (simmer).  

 

-Roy Robinson