Materials Required - In addition to the part you are trying to clean, you need:

» A non-electrically conductive container large enough to hold the parts you want to clean, (i.e. a plastic bucket ? or for large engine parts perhaps an old (fibreglass) bathtub ???). There are other containers like a 45 gallon (about 200 litre) plastic drum that are used for soap and other materials sold in bulk. They are sometimes available cheap or free at recycling centres. An entire single cylinder engine could be put in one of these.

You could use a steel bucket, sink, pot etc. connected to the POSTIVE post as long as you are careful not to let the part being cleaned touch the side of the bucket (short circuit will occur).

» A 12 volt battery or other DC power source with high current capability. A battery (in conjunction with a charger)will always give superior results. A trickle ( 4 to 12 amps) battery charger can be used for small parts. A shop grade "booster" battery charger is quite effective for even large parts. 6 volt DC works as long as the current ability is high. Higher voltage DC sources will work of course BUT then it becomes a shock hazard. (see safety rules below).

» Electrodes to connect to the positive battery terminal. Iron, steel, or any metal can be used. Aluminum used as the positive electrode deteriorates quickly. Iron (and maybe brass) would last longer but requires regular cleaning. The electrode can be wire, bolts, fasteners, screening, sheet metal or thick plate.
** NEW INFO ** Stainless steel WAS previously recommended because the material I was using seemed to last longer and cleaned easier. BUT, as the electrode breaks down,the chromium in stainless steel becomes a compound (hexavalent chromium) which ends up in the liquid and there is the potential for the mist from the bath to become airborn and inhaled. LONG TERM exposure to the skin has been related to skin disorders and LONG TERM inhalation of fumes has been linked to lung cancer. In addition, the chromium in the electrolyte could be considered environmentally harmful so dumping in the ground would not be a responsible thing to do. Instead, allow the liquid to evapourate and dispose of the remaining debris as you would a hazardous waste.
Due to these problems, I can no longer recommend stainless steel to be used at all, especially in this very public forum.

» Water to mix with the electrolyte. Distilled water is not necessary but wouldn't hurt.

» The electrolyte (see above for more information). I used Arm and Hammer WASHING SODA -a common laundry detergent. I have also recently had success with Arm and Hammer Ultra Laundry Detergent. Main advantages here are; easy on your skin, NOT corrosive to the part being cleaned if you happen to leave the part in the solution, no worse than typical soap if it gets in your eyes, AND it leaves a nice soapy smell in the room. Also, the soap effectively gets rid of the putrid smell of old gasoline and oil. (great for cleaning out old gas tanks). Other soaps and detergents work fairly well and I'll leave that for you to experiment with.

Other electrolytes I have tried . Take note of the cautions mentioned

Baking Soda - Sodium Bicarbonite. It works but has much the same properties as salt in that it is mildly corrosive once electricity is applied. I have used it only only for brief tests. It is probably better to use it in place of washing soda than the others which follow.

Table salt- it is corrosive to metal in it own right. It also leaves a punjent chlorine smell behind. (It is sodium chloride). Very bad for aluminum.

Sea salt- it is corrosive to metal in it own right. But it is not the same as table salt. It actually contains many different types of dissolved minerals and salts. Some users have reported success with this. Very bad for aluminum.

Vinegar & acetic acid- Is a mild acid and has been reported to work but the smell it makes is undesirable.

Trisodium Phosphate (TSD) - Found in cleaners for heavy-duty use such as household wall and exterior cleaners, driveway cleaner etc. It is more caustic than soap (harmful to the skin and eyes) so extra caution should be used. The warning on the container says"CAUTION: Contains Trisodium Phosphate. Wear rubber gloves and eye protection. Avoid eye contact or prolonged contact with skin. Wash thoroughly after handling. If eye contact occurs, flush with water for 15 minutes. Consult physician immediately."

These work but are NOT RECOMENDED:

LYE - Sodium Hydroxide - Corrosive to metal in it's own right. Causes much more gasification of the water (LOTS of hydrogen and oxygen gas). Very hard on your skin and even worse CAN CAUSE BLINDNESS if splashed in your eyes. Very bad for aluminum , white metals (zinc alloys) or thinly electroplated materials.

Battery acid (sulphuric, hydrochloric, nitric) - I don't need to spell out that one for you do I? Way too hazardous.