Hi Ya'all, Its time to get back on track with the more mundane thinks of colloidal chemistry.
In my investigations of making CG I have now made 5 experimental runs. All diferent porotocols, and all work some, better than others. The process is easy but somewhat expensive, but there are ways to reduce the cost. The basic process is an adaption of Bill Fernald's floatong electrode process to more aminable practices. #1.) Made with floating electordes, very time consuming and much electrode adjustment. Kimball labs said it was 1.84 PPM of gold. Made with 12 kv ac at 30 ma., not really adequate. #2.) Made with fixed electrodes with "mechanical stirring" Bubblers wont work as the stirring is to maintain as uniform temperature in the DW. NST was 12 kv at 60 ma. Brew time 3 1/2 hours. Kimball labs report 7.68 PPM. Medium dark lavender in color. Crude electrode adjustment used. Brew cell placed ina cut down paint bucket to form a water bath and 7 pounds of ice use to cool the DW. Cooling is and ABSOLUTE must. The arc was 1/4" below the DW surface, and at 90 ma, it blew water everywhere. A real violent arc. As temperature incresaes the arc gets weaker. #3.) Improved micrometer type adjustments on the consumable electrode. 2 NST used for 12kv, at 90 ma. Electrodes 1/2" under water. That was a mistake as the exposed elecrodes stole current from the arc. Brew time was 3 1/2 hours. Not tested but alost the same color as #2. The loss of current from the unprotected electrodes was the primary cause of excess time. #4.) We have arrived!!! 2 NST's 15 kv at 120 ma. the arc is 1/2" below surface and the electrodes are incased in glass except for about 3 /16" exposure. the tip of the consumable electrode sees the size of the other electrode (important) Improved water bath and 16 pounds of cooling ice. Brew time 3 1/2 hours. Color dark blue. To be tested next week. I am working on improving the tooling, the electrode shielding, and a better cooling system. I would like to work around 40 deg F. with 12 kv and 60 ma. as that would be the most economical set up for others. There is no need for long gold leads. one inch on the fixed electorde and 2" on the consumable electrode. I silver soldered the gold on to copper wire to get the required lenght to fit the tooling. Anyway you look at it the cost will be $300.00 to $400.00 to set up. "Ole Bob"
