In my set-up, I am using a small 1gold bar attached to the side of my beaker during electrolysis (I find this much less expensive to use than purchasing wire). I typically produce about 6 quarts of 50ppm colloidal gold in each batch. I find that a small amount of gold atoms plates onto the side of the beaker in the area immediately around the anode. I never see gold visible anywhere else, except that I occasionally see a small number of very small gold flakes on the fluid surface after electrolysis.
- When I increased the amount of Maltodextrin I used, the plating diminished significantly.
- I suspected that more agitation would help (even though I am using a magnetic stirrer and keep the solution boiling the whole time), so I arranged my cathode so that most of it is located below the anode, along the beaker wall. The bubbles from the cathode float up around the anode, generating quite a bit more more stirring, and I have dramatically less gold plating as a result.
On an unrelated note, and for those interested in taking-up electrolysis (but who don't want to pay for an expensive power supply), I have been using a DC-DC Boost Converter as my power supply. It is voltage adjustable, and will put out between 12 and 80V. These are easily found on eBay. Search for something like 'dc boost 600w power supply'. These guys will safely output up to 10 amps (depending on your input/output voltage ratio and output current). I normally electrolyze at around 550mA (and roughly 45-50V). For the longest time the price was around $20, including shipping, but I've noticed that the price is sometimes lower than $15 lately. I use an inexpensive 12V computer power supply to power the DC-DC Converter. This arrangement works well for me and has proved very reliable.
