On a portion of one of these strips, spread all the graphite paste (messy, isn’t it?). You need cover only the first 3" of length, but cover the entire width of this 3" portion. Then place the mesh tube on the graphite and wrap the strip around the tube. The graphite will be facing the meshwork, of course.

     Put the rubber bands or string around the gauze, and set the unit aside to dry (overnight, at least). That takes care of the air electrode for our “fuel cell.” You may be wondering what part the graphite plays in the air electrode. Without getting too technical, it allows the oxygen in the air to enter the electrochemical reaction.

     For the zinc electrode, roll the length of the zinc or galvanized steel into the tube small enough to fit inside the air electrode (but don’t insert it yet). Then wrap the second gauze strip around the zinc.

     After the air electrode has had a chance to dry out, insert the wrapped zinc electrode into the tube core. It should be a snug fit.

     We will need an electrolyte. So dissolve a tablespoon of salt in two or three tablespoons of hot water, and pour this electrolyte into a saucer. That completes all the preparations for the fuel cell. Now, will it work? Let’s see.