The sulfuric cell can be made in many different ways, using many different materials. Rather than giving an exact, cut-and-dried setup, I think it's better to first get an understanding of how it works. Then, you can adapt this knowledge to your particular situation. This subject has been covered many times on the forum in great detail, especially in the early days. I would suggest that you use advanced search. An example of keywords you could use are: sulfuric cell cathode. Where it says Search for Author, type in the name of a person that has been involved in most of the sulfuric cell discussions. Two that come to mind are myself, goldsilverpro, and lazersteve. There are many others that have contributed excellent information to these discussions but, when the subject comes up, one or both of us usually gets involved. In general, this is what you need to know:
(1) Sulfuric acid. The strength should be at least 90%, by weight. Battery acid (about 35-40% H2SO4) won't work unless you first evaporate the water off by heating - the weaker acid will dissolve copper and other base metals very rapidly. If you start with a strength of 95-96%, it helps the stripping speed to add about 5% water, by volume, Always add the acid to the water. Don't add any glycerin - it's not needed.
(2) A container. This can be made of glass, certain types of plastic, or mild steel. Don't use stainless steel.
(3) A Cathode. Steve uses a slab of lead. I always used a mild steel tank to hold the sulfuric and made the tank, itself, the cathode (-).
(4) Anode (+). The parts you are stripping are made the anode. For large pieces, you can clip the parts and put them in the solution. For small parts, such as pins, Steve has designed a copper screen basket. Someone on the forum developed a small tumbler to hold and move the parts around. A tumbler works best.
(5) Amperage. The amperage is what does the stripping. The more amps, the faster the stripping. However, the more amps, the hotter the solution becomes. The hotter the solution, the more attack you will get on the base metals. This can cause big problems. In my opinion, overheating is the cause of most of the problems that people have had with this solution. For this reason, for your small 1 liter bath, I would use a maximum of 2 or 3 amps. I like to keep the solution under 120F and control it by adjusting the amperage. If you use a plastic tank, monitor the temperature closely to keep from melting or softening the plastic. You could use more amps if you keep the solution cool. I haven't done this, but you could probably place the tank in an ice water bath or a large cool water bath.
(6) Voltage. It doesn't make much difference what the voltage is. Control the amperage and let the voltage fall where it may.
(7) What happens. As the gold strips, the amperage drops. When the amps fall to zero, the gold is completely stripped. The gold forms in the solution as a black powder. At the end, when the amps approach zero, I usually increase the voltage. The amps will go up a bit and then finally drop back to zero. With a good setup, normal gold plating should strip in a few minutes.
At some point, there will be so much black powder that it will cause a partial short and the amps won't go to zero. At this point, it is time to harvest the gold. You can remove the electrodes and allow the powder to settle in the form of a sludge. Carefully decant (pour) the solution off of the sludge. The solution can then be re-used. If a little sludge is poured off with the solution, don't worry about it - you'll get it next time.
After decanting, pour the sludge into about 7 to 10 times it's volume of water. Let the gold settle and decant or siphon off the solution. Rinse the sludge a few times. Collect the sludge and dissolve it in a minimum amount of aqua regia and refine as normal.
(8) Safety. Working with strong sulfuric can be very dangerous, since it can quickly and severely burn the skin. Always use rubber gloves and a full face shield. Work slowly and carefully. Think before you do something.
