(04-30-2015, 02:22 PM)Mayhem Wrote: aRM - the process is a simple one, involving a solution of soda ash (used to decrease the pH in swimming pools) a sacrificial anode and a battery charger.  I use a 20L plastic container and lined it with some weldmesh.  The process works by line of sight, so the more anodes you have (either linked or as on piece) the better the process works.

Place the positive lead to the anode and the negative lead to the part you want to clean.  Ensure they are not touching and flick the switch.  For most parts, I leave them in for 15 minutes at a time, cleaning them under hot running water with a stiff brush.  Some parts take a few cycles.  If I remember, I'll take some pictures of my set up.  I am sure I have posted them on here before but cannot find them - probably buried somewhere in this thread!

(05-01-2015, 02:31 PM)Mayhem Wrote: Hi aRM the theory is that the process doesn't work around corners.  Imagine the anode as a light source and the areas of the part on which the light shines will clean up and the parts in the shadows will not.

However, I have found that when placing a thread with a nut in situ, that the threads beneath the nut were also cleaned.  I had expected to have to move the nut and repeat the process.  

The more anodes or the larger the coverage of anodes the quicker the process appears to take place.

(04-30-2015, 06:56 PM)Hopefuldave Wrote: Hi aRM, I'll give some details of my electrolysis setup in case you're interested?

Approx 18x24x12" heavy-duty watertight plastic crate ("stack and store" bins here in the UK), 30A start-and-charge battery charger (old style "dumb" transformer type, the "smart" chargers shut down if they don't see an attached battery), washing soda crystals (Proper Hardware Store) 1 or 2 cups / Imperial Gallon, arc gouging rods (most of the copper stripped off with ferric chloride, enough left to solder the +ve leads onto) as electrodes.
For separation / insulation the plastic grids you sit on sink drainers, thrown-away plastic vegetable crates (around the back of kitchens and supermarkets), spiral cable wrap for threading the electrodes inside e.g. motorbike petrol tanks.

I started out with sheet steel for the sacrificial electrodes, found it produces a really murky solution, lots of muck and "barnacles" on the steel that have to be scraped off to keep the process going, the carbon rods seem to be much cleaner (the solution stays pretty clear, no scraping the barnacles off them), work well in an anodising tank too :)

I attach the workpiece with the charger's -ve lead (and extra pieces with some improvised jumpers, big crocodile clip each end), the +ve goes to a piece of stranded/insulated copper wire soldered to each of the gouging rods in turn (these are held against the inside of the crate by the insulating material, connections above the waterline). mix and pour in the electrolyte (or vice versa), switch on battery charger (current's dependant on the surface area of work and electrode, I've seen 15-20A on many occasions) and go away for a day or three doing something else...

On returning, check all's nice and clean, quick scrub with a scotchbriite pad or similar to loosen any black oxide particles, dry and oil swiftly before it rusts up again :)

One warning - NEVER use stainless steel as the sacrificial anode, it makes SERIOUSLY unpleasand hexavalent chromium in the bath (proper toxic waste, regulated, Official Channels for disposal and all that)
Another warning - Iron/steel only, the bath can have bad effects on aluminium/brass/bronze etc., so stick to ferrous metals